Showing papers on "Enone published in 1977"
TL;DR: In this article, the reaction mixture was quenched by addition of ether followed by careful addition of 3% hydrochloric acid, and the organic layer was washed with 5% sodium hydroxide solution and brine, dried over MgS04, and evaporated to dryness to afford a viscous oil.
Abstract: hexane (Alfa Inorganics) in 2 mL of dry methylene chloride was added 0.11 mL (1.0 mmol) of tert-butyl mercaptan at 0 \"C under nitrogen. The mixture was stirred and allowed to warm to room temperature over a 15-20-min period. The ester or lactone (0.5 mmol) in 0.25 mL of dry methylene chloride was added and the mixture was stirred a t room temperature under nitrogen until TLC indicated that the reaction had gone to completion (usually 4-24 h). The reaction mixture was quenched by addition of ether followed by careful addition of 3% hydrochloric acid. The organic layer was washed with 5% sodium hydroxide solution and brine, dried over MgS04, and evaporated to dryness to afford a viscous oil. All products prepared this way were found by TLC and NMR to be essentially pure upon evaporation of solvent, except for compounds 13 and 14 which were purified by preparative TLC on silica gel PF2jq. Isolated yields of products are given in Table I for several examples.
68 citations
61 citations
TL;DR: In this article, the racemic spirosesquiterpenes β-acorenol (1), β-ACoradiene (2), acorenone-B (3), α-acorenone (4) and acore none (5) have been synthesized from the ester.
Abstract: The racemic spirosesquiterpenes β-acorenol (1), β-acoradiene (2), acorenone-B (3) and acorenone (4) (Scheme 2) have been synthesized in a simple, flexible and highly stereoselective manner from the ester 5 The key step (Schemes 3 and 4), an intramolecular thermal ene reaction of the 1,6-diene 6, proceeded with 100% endo-selectivity to give the separable and interconvertible epimers 7a and 7b Transformation of the ‘trans’-ester 7a to (±)-1 and (±)-2via the enone 9 (Scheme 5) involved either a thermal retro-ene reaction 10 → 12 or, alternatively, an acid-catalysed elimination 11 → 13 + 14 followed by conversion to the 2-propanols 16 and 17 and their reduction with sodium in ammonia into 1 which was then dehydrated to 2 The conversion of the ‘cis’-ester 7b to either 3 (Scheme 6) or 4 (Scheme 7) was accomplished by transforming firstly the carbethoxy group to an isopropyl group via7b → 18 → 19 → 20, oxidation of 20 to 21, then alkylative 1,2-enone transposition 21 → 22 → 23 → 3 By regioselective hydroboration and oxidation, the same precursor 20 gave a single ketone 25 which was subjected to the regioselective sulfenylation-alkylation-desulfenylation sequence 25 → 26 → 27 → 4
39 citations
TL;DR: In this paper, the photochemistry of the α,β-unsaturated γ,δ-epoxy-enones was determined by: (i) C(γ)-O-scission of the epoxide (vinylogous β-cleavage of Type A); (ii) C (γ)-C(δ) cleavage of the oxirane (VOG-β) of Type B); (iii) (E/Z)-isomerization of the enone chromophore.
Abstract: Photoinduced Vinylogous β-Cleavage of Epoxy-enones of the Ionone Series
The photochemistry of the α,β-unsaturated γ,δ-epoxy-enones 1–3 is determined by: (i) C(γ)-O-scission of the epoxide (vinylogous β-cleavage of Type A); (ii) C(γ)-C(δ)-cleavage of the oxirane (vinylogous β-cleavage of Type B); (iii) (E/Z)-isomerization of the enone chromophore. In contrast, 4 with tertiary C(β) shows no Type B cleavage.
Type A cleavage is induced both by n,π*- and π,π*-excitation and arises probably from the T1-state, but Type B cleavage is observed only on π,π*-excitation and represents presumably a S2-reaction.
On Type A cleavage 1–4 undergo 1,2-alkyl-shifts to 1,5-dicarbonyl compounds (15–18, 25–28, 34 and 35) or rearrange to dihydrofuranes (7 and 30). The isomerization 17 proceeds by a stereoselective [1,3]-sigmatropic shift.
On Type B cleavage 1–3 isomerize to a bicyclic enol-ether (8, 29) or to a monocyclic enol-ether (9; product of a homosigmatropic [1,5]-shift) or undergo fragmentation to isomers such as allenes 10, 22 and 31 or cyclopropenes 11 and 21.
The non-isolated, unstable (Z)-epoxy-enones 14, 19, 24 and 38 isomerize by fragmentation to the furanes 12, 23, 33 and 39 respectively, on contact with traces of acid or by heating. However, for 19 and 4, Type B cleavage may lead to the furanes 23 and 39.
On UV. irradiation of the epoxy-enone 4 the initially formed (E/Z)-isomers 34 and 35 yield on π,π*-excitation the enones 37 and 40 by a vinylogous β-fragmentation. In addition, on n,π*-excitation 34 isomerizes to 35, which decarbonylates exclusively to the enone 37.
The reactions of 1–4 with BF3 · O(C2H5)2 were also studied (see appendix). The epoxy-enones 1 and 2 isomerize by an 1,2-alkyl shift in good yield to the 1,4-dicarbonyl compounds 79 and 81, whereas 3 gives the 1,4-diketone 83, and in small amounts the 1,5-diketone 84. On the other hand, 4 is converted to the fluorohydroxy-enone 85 and to the 1,5-dicarbonyl product 34, the only isomer in this series which is identical with one of the photoproducts.
38 citations
TL;DR: The sulphenylated phosphine oxides Ph2P(O)·CH(SR2)R1, easily prepared from triphenylphosphine, diphenyl or dimethyl disulphide, and an alkyl halide, form anions which act as acyl anion equivalents.
Abstract: The sulphenylated phosphine oxides Ph2P(O)·CH(SR2)R1, easily prepared from triphenylphosphine, diphenyl or dimethyl disulphide, and an alkyl halide, form anions which act as acyl anion equivalents. Reaction with aldehydes and ketones gives vinyl sulphides, which can be hydrolysed to carbonyl compounds. Reaction with α-phenylthio- and α-methoxy-aldehydes and ketones gives enone precursors. The scope and limitations of the method are described.
37 citations
TL;DR: In this paper, the structural and configurational assignments were based on the mode of preparation and from spectroscopic data, most conveniently from p.m. spectra and chiroptical properties.
33 citations
TL;DR: In this article, the 6-chloro-2-cyclohexenones 3, 6 and 11, and the 5-chloros 2-cyclopentenone 15 were newly synthesized and the results obtained with compounds 3 and 15 in photocycloadditions to olefins show that the oxetane vs cyclobutane product ratio is reduced by the substitution of florine by chlorine in the α′ -position of the enone.
Abstract: The 6-chloro-2-cyclohexenones 3, 6 and 11, and the 5-chloro-2-cyclopentenone 15 were newly synthesized. The results obtained with compounds 3 and 15 in photocycloadditions to olefins show that the oxetane vs. cyclobutane product ratio is reduced by the substitution of florine by chlorine in the α′ -position of the enone. No oxetanes are formed in the intramolecular photocycloaddition of 6. Compound 11 does not photoadd to olefins. The newly synthesized 2-chloro-3-cyclohexenones 8 and 9 are also photostable towards light of λ=366 nm, but π-π*-excitation (λ=254 nm) in pentane leads to the formation of 4,4-dimethylcyclohexanone (29).
20 citations
TL;DR: In this article, a conjugated enone was synthesized from 3β-hydroxy-5alpha-pregnan-20-one by reaction of the tosylhydrazone with butyllithium to introduce the vinyl moiety.
16 citations
TL;DR: In this paper, the same authors investigated the S2 (π,π*) state of enone S2 reactivity and showed that it is possible to achieve a 0.29 quantum yield for (Z)-6 9 under optimum conditions at 254 nm.
Abstract: 4a-(Z-1-Propenyl)-bicyclo[4.4.0]dec-1(8a)-en-2-one (6) and 4a-(Z-1-propenyl)-bicyclo[4.4.0]deca-1(8a), 7-dien-2-one (17) undergo an intramolecular hydrogen transfer from the methyl group of the propenyl substitutent to the α-carbon atom of the enone group, and cyclization to the [4.4.3]propellane derivatives 9 and 30, respectively, when excited in the π π* wavelength region. The quantum yield for (Z)-6 9 under optimum conditions is 0.29 at 254 nm. These reactions occur specifically from the S2 (π,π*) state, competing with the S2 T decay. The triplet reactions of 6 are E–Z double-bond isomerization, double-bond shift to (E,Z)-8, and rearrangement to (E)-10. Further investigations concern some structural limitations in the scope of the reaction type 6 9 and enone S2 reactivity in general.
15 citations
TL;DR: In this paper, the title compound 4 reacted with hydrazoic acid to give exclusively an adduct having the threo configuration, whose structure was established by reduction to the lyxo derivatives 8 and 10.
14 citations
TL;DR: In this paper, an easy synthetic route to 2-hydroxy-3-methyl cyclopent-2-enone from 5-methylfurfuryl alcoho is described, in which the key intermediates are derivatives of 2,5-dimethoxy tetrahydrofuran prepared from the anodic oxidation of the corresponding derivatives of furan, followed by hydrogenation.
Abstract: A new, easy synthetic route to 2-hydroxy-3-methyl cyclopent-2-enone from 5-methylfurfuryl alcoho is described, in which the key intermediates are derivatives of 2,5-dimethoxy tetrahydrofuran prepared from the anodic oxidation of the corresponding derivatives of furan, followed by hydrogenation.
TL;DR: In this article, the effect of binding a metal to the 1,3-diene unit is shown to raise the free energy of activation for ring closure by about 5 kcal/mol.
Abstract: The way in which the stabilities and reactivities of polyolefins are modified by coordination to transition metals has received considerable attention in recent years. Preparations of stable transition metal complexes of exceedingly reactive polyolefins, which are not normally isolable at ambient temperatures, represent some of the most intriguing and synthetically useful applications to emerge from this area. For example, the iron tricarbonyl moiety has been used successfully to stabilize and render isolable as iron complexes such highly reactive polyolefins as cyclopentadienone,’ cyclobutadiene,2 7-n0rbornadienone,~ and trimethylenemethane.4 As demonstrated by the classic work of Pettit on cyclobutadieneiron tricarbonyl, such complexes can not only be used to “store” the ligand but, through oxidative cleavage of the complex, can also serve as a convenient source of the free polyolefin for use in synthesk2 One particular aspect of this area of chemistry that has occupied our attention over the last few years has been the modification, through binding to transition metals, of the thermal chemistry of cyclic polyolefins capable of undergoing electrocyclic ring-opening and ring-closing reactions. We have observed that binding a metal to polyolefinic systems capable of such valence tautomerism can have substantial effects on both the rates of interconversion of the valence isomers and on the position of the tautomeric equilibrium. The first example of such an observed ring closure was our observation5 that protonation of cyclooctatetraeneiron tricarbonyl at low temperatures led to the cyclooctatrienyliron tricarbonyl cation, 1, which undergoes ring closure at -60°C (AG’ = 15.7 kcal/mol) to yield the previously observed bicyclo[5. i.O]octadienyliron tricarbonyl cation, 2 (see SCHEME 1). In this particular case, a meaningful comparison with the free ligand system is difficult to make, because protonation of free cyclooctatetraene leads to the homotropylium ion.6 A more direct comparison can be made in the case of cis4-cyclononatetraene (see SCHEME 1). Whereas cis4-cyclononatetraeneiron tricarbony1 (3) is stable at room temperature and undergoes ring closure to cisdihydroindeneiron tricarbonyl(4) at 100°C (AG’ = 28.4 kcal/mol),’ free cyclononatetraene undergoes ring closure to cis-dihydroindene rapidly at room temperature (AG’ 23 kcal/mol).* Thus, the effect of binding iron to the 1,3-diene unit is to raise the free energy of activation for ring closure by about 5 kcal/mol. A system for which more quantitative data is available involves the equilibrium between 1,3,5-cyclooctatriene (5) and bicyclo[4.2.0]octadiene (6), established via electrocyclic ring-opening and ring-closing reactions (see SCHEME 1). Huisgen et al. .
TL;DR: In this article, photochemical excitation of cyclopentadienyl- and methylcyclopentadiyl-tricarbonylmanganese in THF followed by addition of an α-enone produced monosubstitution and afforded olefinic enone complexes RCpMn(CO) 2 (enone).
TL;DR: Silyl ethers of biacetyl enols, an enone 2 and a diene 3, were prepared in this article, and cyclodimerization of 2 gave a dihydropyran 4, while reaction of 3 with 2, maleic anhydride, and ethyl acrylate gave Diels-Alder adduct 5, 8, and 9, respectively.
Abstract: Silyl ethers of biacetyl enols, an enone 2 and a diene 3, were prepared. Cyclodimerization of 2 gave a dihydropyran 4, while reaction of 3 with 2, maleic anhydride, and ethyl acrylate gave Diels–Alder adduct 5, 8, and 9, respectively. The compounds 4 and 5 were desilylated to afford 6 and a mixture of 7 and 7′, respectively.
TL;DR: The [π2 +π2] photocycloaddition reactions between cyclopent-2-enone and various electron-rich alkenes proceed in both good quantum yields and useful chemical yields.
Abstract: The [π2 +π2] photocycloaddition reactions between cyclopent-2-enone and various electron-rich alkenes proceed in both good quantum yields and useful chemical yields. The stereochemistry of the cycloadducts (1)–(5) has been determined by chemical ionization mass spectrometry and chemical transformations. The regioselectivity increases with increasing nucleophilicity of the alkene, and the stereoselectivity depends on the steric properties of the alkene substituents. The reaction between cyclopent-2-enone and 1-ethoxy-1-ethylthioethylene occurs in a fully regio- and stereo-specific way.
TL;DR: Several cyclic β-diketones were prepared by acid-catalysed intramolecular cyclisation of appropriate oxo-acids as discussed by the authors, including bicyclo[4.2.1]nonane-2,8-dione, which was converted into the bridgehead enone named in the title.
Abstract: Several cyclic β-diketones were prepared by acid-catalysed intramolecular cyclisation of appropriate oxo-acids. One of them, bicyclo[4.2.1]nonane-2,8-dione, was converted into the bridgehead enone named in the title. Some reactions of this compound are reported. Reaction of (5R*,6R*)-6-tosyloxyspiro[4,4]nonan-1-one with boiling collidine gave 1,2,3,5,6,7-hexahydroinden-4-one by elimination and rearrangement.
TL;DR: In this paper, the temperature dependence of model enone compounds in poly (methyl methacrylate) matrix and glassy methylcyclohexane/isopentane solution and of enones formed from thermal oxidation of poly (butadiene) has been studied over the temperature range 77-220°K.
TL;DR: In this article, the reaction of 4-Pyrones and chromone with carbanions to the anion of acetophenone to the phenol derivatives 5a and 10 was investigated.
Abstract: Pyron (1) und 2,6-Dimethylpyron (6) reagieren mit dem Anion von Acetophenon zu den Phenol-Derivaten 5a und 10; aus Chromon (12) entstehen mit Aceto- bzw. Propiophenon-Anionen die Enone 13a und b, die sich in die Pyridin-Derivate 14a und b uberfuhren lassen.
Reaction of 4-Pyrones and Chromone with Carbanions1)
Pyrone (1) and 2,6-dimethylpyrone (6) react with the anion of acetophenone to the phenol derivatives 5a and 10. From chromone (12) and the acetophenone or propiophenone anions the enones 13a and b are obtained. They are converted into the pyridine derivatives 14a and b.
TL;DR: In this paper, a 1H-quinolone was synthesized by intramolecular Michael addition of an amino enone (IV) and catalytic hydrogenation of a bicyclic lactam (V).
Abstract: cis-Octahydro-7 (1H)-quinolone (III) was synthesized stereoselectively by two different routes, one via intramolecular Michael addition of an amino enone (IV) and the other via catalytic hydrogenation of a bicyclic lactam (V). Detailed examinations of hydrogenation products in the latter was also described.
TL;DR: In this paper, perimidin-4-and-6-one systems reacted readily with primary and secondary amines at room temperature, and side-chain amination of 9-methyl substituents was observed, analogous to processes encountered in quinone chemistry.
Abstract: π-Deficient perimidin-4- and -6-one systems reacted readily with primary and secondary amines at room temperature. Nucleophilic attack occurred not only at the enone double bond, but also at positions 7 and 9 on the benzenoid ring. Highly coloured mono-, di- or tri-aminated derivatives were thereby obtained. A significant degree of bond fixation was indicated. Side-chain amination of 9-methyl substituents was observed, analogous to processes encountered in quinone chemistry. On continued contact with amine the products were converted partly into 9-formyl derivatives and partly into 9-amino compounds.
TL;DR: The decomposition of 1-hydroperoxy-1-isopropylnaphthalen-2(1H)-one by various bases has been studied in this article.
Abstract: The decomposition of 1-hydroperoxy-1-isopropylnaphthalen-2(1H)-one (1) by various bases has been studied. Complex redox and rearrangement processes lead to 1-hydroxy-1-isopropylnaphthalen-2(1H)-one (11), the trans-epoxide (12) of this enone, and the rearrangement product (14) of that epoxide, along with r-3,4-epoxy-3,4-dihydro-c-2-hydroxy-2-isopropylnaphthalen-1(2H)-one (15) and an acid resulting from oxidation and ring cleavage. Both intra- and inter-molecular oxygen transfers between the hydroperoxy and enone groups probably occur.
TL;DR: The spectral data of the enone (1) are not identical with the corresponding values reported for a triterpene ketone (alnus-5(10)-en-1-one) isolated from Euphorbia nerifolia.
Abstract: The Ratcliffe oxidation of D:B-friedo-olean-5(10)-ene (2) gave D:B-friedo-olean-5(10)-en-1-one (1), D:B-friedo-olean-5(10)-en-6-one (3), and D:B-friedo-olean-5(10)-ene-1,6-dione (4). The spectral data of the enone (1) are not identical with the corresponding values reported for a triterpene ketone “alnus-5(10)-en-1-one” isolated from Euphorbia nerifolia, indicating that the structure of this natural triterpene must be revised.
TL;DR: In this article, the relative basicities of 3-aryl-5-phenylcyclohex-2-en ones have been determined by i.r. spectroscopy from the shifts of the stretching frequency of the hydroxy-group of phenol hydrogen-bonded with these ketones and from the νco values (in KBr, CCl4, and CHCl3) together with the dipole moments (in benzene).
Abstract: The relative basicities of 3-aryl-5-phenylcyclohex-2-en ones have been determined by i.r. spectroscopy from the shifts of the stretching frequency of the hydroxy-group of phenol hydrogen-bonded with these ketones and from the νco values (in KBr, CCl4, and CHCl3) together with the dipole moments (in benzene). The values are discussed and ccmpared with those of arylideneacetones having analogous conjugated systems. It is shown that the fixed s-trans-configuration of cyclohexenone derivatives causes their high polarities and basicities. Correlation analysis has been performed and it is found that the rigid π-system of cyclohexenone possesses a substantially better transmission of electronic influence in comparison with carbonyl compounds with an open-chain structure.
01 Jan 1977
TL;DR: In this article, a large number of the 11-deoxyprostaglandin E 1 analogues have been screened for bronchodilator and anti-secretory activity.
Abstract: (±)-11-Deoxyprostaglandins of the E 1 series are synthesised by elaboration of the aldehyde (vii) which is prepared from the enone (iv) via thenitrile (vi) or nitromethyl compound (xii). The stereochemistry of the intermediates is discussed and evidence presented thatnitrile and nitromethyl compounds are cis/trans mixtures and that most of the cis is converted to the trans form at the aldehyde stage.11-Deoxy-PGF 1 analogues are prepared directly from the nitrile (v) via the aldehyde (xvi). The synthesis has also been adapted to give 15- and 16-methyl analogues, and the finding that epoxides of 2-alkylcyclopent-2-enones react with acetic acid to give 5-acetoxy-2-alkylcyclopent-2-enones affords an approach to10-hydroxyprostenoic acids. A large number of the 11-deoxypros-taglandin E 1 analogues have been screened for bronchodilator and anti-secretory activity. Numerous side effects have been observed in animals and in man after treatment with both natural and synthetic analogues of PGE 1 and PGE 2 . We have designed new screening tests in an effort to detect these side effects in animals during the routine evaluation of the pharmacological properties ofour analogues. This has enabled us to derive an index of selectivity for each compound, and the pharmacological profiles of the more selective analogues are described in this paper.
Patent•
03 May 1977TL;DR: In this paper, a four-stage reaction sequence was proposed to obtain enone intermediates for prostaglandin analogues from 4 beta -dimethoxymethyl-2,3,3 alpha beta,6 alpha beta -tetrahydro-5 alpha -hydroxy-6 beta -iodo-2-oxocyclopenteno[b]furan in substantially increased yield.
Abstract: The disclosure relates to a novel four-stage reaction sequence whereby known enone intermediates for prostaglandin analogues may be obtained from 4 beta -dimethoxymethyl-2,3,3 alpha beta ,6 alpha beta -tetrahydro-5 alpha -hydroxy-6 beta -iodo-2-oxocyclopenteno[b]furan in substantially increased yield. A novel intermediate produced in the novel four-stage reaction sequence is also claimed.
TL;DR: In this article, the β-ketoglutaric acid with benzil in ethanolic KOH furnished the 1:1 adduct, and partial decarboxylation gave the monoacid, the structure of which was erroneously reported.
Abstract: Reaction of β-ketoglutaric acid with benzil in ethanolic KOH furnished the 1:1 adduct 7. Hydrolysis and partial decarboxylation gave the monoacid 8, the structure of which was erroneously reported ...
TL;DR: In this paper, the 6-chloro-2-cyclohexenones 3, 6 and 11, and the 5-chloros 2-cyclopentenone 15 were newly synthesized and the results obtained with compounds 3 and 15 in photocycloadditions to olefins show that the oxetane vs cyclobutane product ratio is reduced by the substitution of florine by chlorine in the α′ -position of the enone.
Abstract: The 6-chloro-2-cyclohexenones 3, 6 and 11, and the 5-chloro-2-cyclopentenone 15 were newly synthesized. The results obtained with compounds 3 and 15 in photocycloadditions to olefins show that the oxetane vs. cyclobutane product ratio is reduced by the substitution of florine by chlorine in the α′ -position of the enone. No oxetanes are formed in the intramolecular photocycloaddition of 6. Compound 11 does not photoadd to olefins. The newly synthesized 2-chloro-3-cyclohexenones 8 and 9 are also photostable towards light of λ=366 nm, but π-π*-excitation (λ=254 nm) in pentane leads to the formation of 4,4-dimethylcyclohexanone (29).
TL;DR: In this article, it was argued that halogenation of cholest-5-en-3-one differs from that of Cholest5-ene and its 3-monosubstituted derivatives in the ratio of attack on the α- and β-faces of the molecule for two main reasons: because of the availability of a concerted pathway for substitution involving the chair conformation of ring A of the enone, and because in non-concerted pathways for addition and substitution, ring A can reach a boat conformation.
Abstract: Reactions of cholest-5-ene or its 3β-substituted derivatives with chlorine in chloroform or chlorobenzene give as kinetically controlled products the expected 5α,5β-dichloride, accompanied by the isomeric 5β,6α-dichloride as a minor component. The proportion of the latter decreases with the electron-withdrawing power of the 3β-substituent. Neither added pyridine nor added chloride ion affects the product proportions significantly. Cholest-5-en-3-one, on the other hand, when treated with chlorine in chlorobenzene containing 2-methyloxiran gives not only the expected 5α,6β-dichloride but also much 6α- and 6β-chlorocholest-4-en-3-one. Comparison with the results for 4β-deuteriocholest-5-ene shows that the formation of 6α-chlorocholest-4-en-3-one involves mainly displacement of the 4β-hydrogen atom, and that the formation of its 6β-isomer involves mainly but not exclusively displacement of the 4β-hydrogen atom. Similar products are obtained in deuteriochloroform containing pyridine; in acetic acid, substitution is accompanied by little addition and much unidentified material The results are compared with the corresponding results for bromination, epoxidation, and iodination. It is argued that halogenation of cholest-5-en-3-one differs from that of cholest-5-ene and its 3-monosubstituted derivatives in the ratio of attack on the α- and β-faces of the molecule for two main reasons: because of the availability of a concerted pathway for substitution involving the chair conformation of ring A of the enone, and because in non-concerted pathways for addition and substitution, ring A of the intermediate halogenonium ion derived from the enone can reach a boat conformation. Two types of AdE3 additions having different stereochemical preferences can also be recognised.
Patent•
22 Feb 1977
TL;DR: In this paper, a process for the preparation of bicyclic enon compounds is described, in which a lactone diol is selectively oxidized to obtain a hydroxy-aldehyde with one hydroxyl group and the reaction product can be acylated or silylated.
Abstract: A process for the preparation of bicyclic enon compounds in which a lactone diol is selectively oxidized to obtain a hydroxy-aldehyde with one hydroxyl group and, without isolation, the hydroxy-aldehyde is reacted with a phosphorus compound. The reaction product can be acylated or silylated.