Showing papers on "Derivative (chemistry) published in 1979"
TL;DR: In this article, an efficient method of removing the benzyl protecting group in the biphenyl derivative of lythraceous alkaloids was proposed. But this method is unsuitable because of the structural limitations.
Abstract: In the course of our synthetic studies of Lythraceous alkaloids,' we needed an efficient method of removing the benzyl protecting group in the biphenyl derivative 1 which could be an important synthetic intermediate for lythranidine (2).2 Among the reported methods for removal of the benzyl protecting group, catalytic hydrogenoly~is~ or reductive cleavage with sodium in ethanol4 or in liquid ammonia5 seemed unsuitable because of the structural limitations. Attempted debenzylation of compound 1 with concentrated hydrochloric acid in refluxing ethanol6 gave a complex mixture of products. Trifluoroacetic acid has been used to cleave a number of aromatic benzyl ethers when the aromatic ring contains either meta-directing or ortho- and para-directing groups.: Applying this reagent to the compound 1 also resulted in the formation PhCH, '0 dCH
133 citations
TL;DR: In this paper, the synthesis of E -5(2-bromovinyl)-2-deoxyuridine in good yield via an intermediate organopalladium derivative is described.
121 citations
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69 citations
TL;DR: In this paper, Glucosides and disaccharides were obtained from 2-benzothiazolyl 2,3,4,6-tetra-Obenzyl-1-thio-D-glucopyranoside and alcohols including sterically hindered secondary alcohols.
Abstract: Glucosides and disaccharides were prepared in good yields from 2-benzothiazolyl 2,3,4,6-tetra-O-benzyl-1-thio-D-glucopyranoside and alcohols including sterically hindered secondary alcohols in the presence of cupric triflate α-Glucosides were obtained predominantly by this method
60 citations
TL;DR: In this paper, the reaction of tetrasodium tetrathiafulvalene-tetrathiolate with transition metal salts leads to the formation of tetrathyfulvalenes-metal bisdithiolene oligomers which in the case of the nickel derivative possesses unusually high conductivity (ca. 30 Ω-1 cm-1).
Abstract: Reaction of tetrasodium tetrathiafulvalene-tetrathiolate with transition metal salts leads to the formation of tetrathiafulvalene-metal bisdithiolene oligomers which in the case of the nickel derivative possesses unusually high conductivity (ca. 30 Ω–1 cm–1).
57 citations
TL;DR: In this article, the synthesis of both 7,8-dimethyl-8-hydroxy-5-deazoriboflavin and 8-dimethylamine-8,hydroxymethyl-5,de-de-drugs (5-DEBOD) was shown to be identical to Factor 420 (FO).
Abstract: Procedures for the synthesis of both 7,8-dimethyl-8-hydroxy-5-deazoriboflavin and 8-dimethyl-8-hydroxy-5-deazoriboflavin as well as experiments confirming that the first compound is identical with the riboflavin level derivative obtained by the acid hydrolysis of Factor 420 (FO). This Factor 420 is one of two novel enzymes contained in methane-producing bacteria which participate in the eight-electron reduction of CO/sub 2/ to CH/sub 4/. The aggregate chemical and biochemical data support the supposition that the methanogen redox coenzyme is a derivative of the first mentioned compound.
57 citations
TL;DR: In this paper, the reaction of L -ascorbic acid with hydrogen bromide in acetic acid gave 6bromo-6deoxy-L-ascorbIC acid, which was converted into 5,6-dideoxy- D - glycero -hex-2,3-enono-1,4-lactone.
TL;DR: In this paper, the role of 24-hydroxylation in the metabolism of vitamin D3 was investigated using a commercially available lithocholic acid derivative to study the role.
TL;DR: The heartwood of Libocedrus yateensis has been found to contain cumic acid and several related hydroxyacids so far not reported from any conifer, a sesquiterpene (−)-cryptomerione and (E, E)-1,4-bis-(p-hydroxyphenyl)-buta-1,3-diene, both known from Taxodiaceae.
TL;DR: Diphenyl(2-cyclopentadienylethyl)phosphne yields, by treatment of its cyclopentadiylstannyl derivative with BrMn(CO) 5, a substituted cymantrene as discussed by the authors.
TL;DR: In this paper, an effective and convenient synthesis of 2-pyridinethiol esters of carboxylic esters was developed which involves the interaction of a carboxylate salt with the S-chloroformyl derivative of 2 -pyridine.
TL;DR: In this article, the configuration of D-Isothreonine, (2R,3S)-3-amino-2-hydroxybutanoic acid (4), was deduced from the shift of molecular rotation, Cotton effect in ORD curve of 4, and NMR measurement of its oxazolidone derivative.
Abstract: D-Isothreonine, (2R,3S)-3-amino-2-hydroxybutanoic acid (4), was readily prepared by the ammonolysis of optically active 2-bromo-3-hydroxybutanoic acid derived from L-threonine. The configuration of 4 was deduced from the shift of molecular rotation, Cotton effect in ORD curve of 4, and NMR measurement of its oxazolidone derivative.
TL;DR: In this article, the authors showed that methyl 4-O -benzoyl-2,3- O -isopropylidene-α- l -rhamnopyranoside and methyl 5-O-benzyl-2.3-OISOPropylIDene-β- d -ribofuranoside with dibromomethyl methyl ether gave 2-bromo-2-deoxy-3 O -formyl glycosyl bromides in good yields.
TL;DR: A new compound isolated from cultures of Aspergillus candidus Link is shown to be 3-hydroxyterphenyllin, which was assigned by comparing the 1H and 13C nmr spectra of the metabolite and its acetate derivative with those of ter phenyllin and terphenyll in triacetate.
Abstract: A new compound isolated from cultures of Aspergillus candidus LINK is shown to be 3-hydroxyterphenyllin. The structure was assigned by comparing the 1H and 13C nmr spectra of the metabolite and its acetate derivative with those of terphenyllin and terphenyllintriacetate.
Journal Article•
01 Dec 1979
TL;DR: In this article, the results of an X-ray analysis of the reaction of erythromycylamine with (2methoxy-ethoxy)-acetaldehyde (Maier et al., 1977) are reported.
Abstract: Antibiotics of the erythromycin group are well-known drugs with activity against Gram-positive bacteria. The title compound, formula C42H78N2014, which was obtained from the reaction of erythromycylamine with (2methoxy-ethoxy)-acetaldehyde (Maier et al., 1977) is expected to be active also against Gram-negative bacteria and to have improved pharmacokinetic properties. Since is was ambiguous, from spectroscopic data, whether the compound had an oxazine structure (Fig. la) or an oxazepine structure (Fig. lb), an X-ray analysis was carried out. Large colorless single crystals were obtained from evaporation of a solution in acetonitrile. The crystals were found to decompose within a few hours in the open air; they were stable if sealed in a glass capillary together with a drop of acetonitrile. The crystal data are: space group orthorhombic P21212, unit-cell constants a = 31.320(4), b = 13.205(5), c = 12.481(3) A, Z = 4 . The intensities of 4853 independent reflections were recorded with Nifiltered Cu Kot radiation (h= 1.5418 A) on a Stoe four-circle diffractometer up to a 0-limit of 62. 5 ~ using the r scan technique: 768 reflections having intensities less than twice the statistical error were coded as unobserved. The structure was solved with MULa'AN (Main et al., 1971), and refined by least-squares methods using the corresponding programs of the XRAY-76
TL;DR: Penta-N,O-acetyl-DL-validamine was prepared from readily available endo-2, exo-3-diacetoxy-endo-6-acetoxymethyl-7-oxabicyclo[2.2]heptane in three steps in an overall yield of 36% as mentioned in this paper.
Abstract: Penta-N,O-acetyl-DL-validamine was prepared from readily available endo-2, exo-3-diacetoxy-endo-6-acetoxymethyl-7-oxabicyclo[2.2.1]heptane in three steps in an overall yield of 36%.
TL;DR: In this article, a 3-mercaptopropanoyl derivative inhibited angiotensin converting enzyme with I 50 = 1.7 μM using 1-pyrroline trimer and diethyl phosphite.
TL;DR: Under strictly anaerobic conditions deoxyhaemOCyanin and methaemocyanin, treated with NO, gave the same derivative as shown by circular dichroism and EPR spectra.
Abstract: Deoxyhaemocyanin, treated with NO under strictly anaerobic conditions, yielded methaemocyanin and N2O in a fast reaction.
In a further slow reaction this methaemocyanin lost its triplet electron paramagnetic resonance (EPR) signal at g= 4 and yielded a nitrosyl derivative with a characteristic g= 2 Cu(II) EPR signal, indicating the binding of a single NO per copper pair. Thus under strictly anaerobic conditions deoxyhaemocyanin and methaemocyanin, treated with NO, gave the same derivative as shown by circular dichroism and EPR spectra.
Methaemocyanin yielded, moreover, reversibly a nitrite derivative, characterized by a triplet signal at g= 4 with 7 hyperfine lines.
Patent•
24 Sep 1979TL;DR: In this paper, a thioether and a xanthine derivative were combined with a trans-cutaneous electrophoresis to provide a slimming and anti-cellulitis action when applied to the body.
Abstract: The invention provides compositions which have a slimming and anti-cellulitis action when applied to the body, topically with massage or using trans-cutaneous electrophoresis. The compositions contain, in combination, a thioether and a xanthine derivative.
Patent•
26 Mar 1979TL;DR: In this article, the present invention is prepared by acylating hydrocortisone 17-butyrate with propionic acid anhydride or halide, which has excellent anti-inflammatory effect, percutaneous absorption and less side effect.
Abstract: 17α-butyryloxy-11β-hydroxy-21-propionyloxy-4-pregnen-3,20-dione, i.e., hydrocortisone 17-butyrate 21-propionate of the present invention is prepared by acylating hydrocortisone 17-butyrate with propionic acid anhydride or halide. The compound of the present invention has excellent anti-inflammatory effect, percutaneous absorption and less side effect.