Showing papers in "Tetrahedron Letters in 1984"

TL;DR: A mild olefination procedure, utilizing LiCl and an amine, has been developed for use with base-sensitive aldehydes and phosphonates as discussed by the authors.

TL;DR: Aromatic nitro compounds are readily reduced by SnCl2, 2 H2O in alcohol or ethyl acetate or by anhydrous SnCl 2 in alcohol where other reducible or acid sensitive groups such as aldehyde, ketone, ester, cyano, halogen and O-benzyl remain unaffected as mentioned in this paper.

TL;DR: The three component reaction (Et 2 N) 3 P/CF 3 Br/R n SiCl 4-n (n = 1 2,3; RCH 3,Ph) gave CF 3 -substituted organyl(chloro)silanes for the first time as mentioned in this paper.

TL;DR: The reaction of diethylzinc with benzaldehyde catalyzed by a small amount of chiral 2-amino-1-alcohols in toluene at room temperature gave optically active 1-phenylpropan-1ol almost quantitatively in ∼, 50% ee as discussed by the authors.

TL;DR: In this paper, a deprotonation of ketones and esters with lithium dialkylamides in the presence of trimethylchlorosilane leads to enhanced selectivity for the kinetically generated enolate.

TL;DR: The title glycosylation method is economical and operationally simple as mentioned in this paper, and the steric course is highly influenced by the nature of the reaction media, which is the most common reaction media used in glycolysis.

TL;DR: Organocerium reagents, prepared from organolithiums and anhydrous cerium (III) chloride, react cleanly with easily enolizable ketones to afford the addition products in good to excellent yields as discussed by the authors.

TL;DR: In this paper, the conformational analysis of the hydroxymethyl groups of free, acetylated and benzoylated D-glucopyranoses and D-galactopyransoses was described based on the 1 H-NMR spectra of sugars chirally deuterated at C6.

TL;DR: The Sharpless reagent (Ti(OiPr) 4 + 1 mol eq. H 2 O) was used in this paper to cleanly oxidize sulfides into sulfoxides in dichloromethane.

TL;DR: The high endo/exo product ratio in the Diels-Alder reaction of cyclopentadiene with methyl vinyl ketone in water does not reflect aggregation, but the ratio is affected by salts which change the hydrophobicity of the medium.

TL;DR: Alkali metal trimethylsilanolates, M⊕⊖OSiMe3, convert carboxylic acid derivatives into their corresponding anhydrous acid salts under mild non-aqueous conditions as mentioned in this paper.

TL;DR: In this article, water-soluble host molecules derived from calix[6]arene were synthesized and measured using fluorescence and absorption spectral probes, showing that the cavity of calix can accept a naphthalene molecule but not a pyrene molecule and that (1b) has a hydrophobic cavity constructed from the aggregate of the hexyl groups.

TL;DR: Phenylalanine ethyl ester-selective polymers have been prepared using the ion-pair association of substrate and carboxyl-containing vinyl monomers in the polymerization step as discussed by the authors.

TL;DR: In this article, photolysis of several hydroxy compounds in presence of iodosobenzene diacetate and iodine leads to alkoxy radical derivatives which undergo intramolecular hydrogen abstraction to produce cyclic ethers in good yield.

TL;DR: In this paper, various aliphatic and aromatic nitro compounds were selectively and rapidly reduced to their corresponding amino derivatives in very good yield using anhydrous ammonium formate as a catalytic hydrogen transfer agent.

TL;DR: In this article, the unit peptide, cadystin, of the cadmium-binding peptides occurring in a fission yeast was further separated into two major components.

TL;DR: Berberis darwinii Hook (Berberidaceae) has yielded the lactams (±)-nuevamine (7) and (−)-lennoxamine (8) as discussed by the authors.

TL;DR: In this article, the asymmetric synthesis of threo -β-hydroxy-L-glutamic acid via a stereo-selective addition to the chiral penaldic acid equivalent was described.

TL;DR: In this paper, a two-stage, one-flask operation using NaBH4/2-propanol, then acetic acid was used to convert phthalimides to primary amines.

TL;DR: The reactivity pattern of the butyllithium/potassium tert-butoxide mixt. with cumene differs significantly from that of BuK and thus disproves the claimed identity of these two reagents as mentioned in this paper.

TL;DR: In this article, the reformatskii addition to aldehydes and ketones to form 2,2-difluoro-3-hydroxyesters is described.

TL;DR: In this paper, the anti-stereochemistry observed in organocuprate SN2′ displacements can be rationalized as a stereoelectronic effect arising from bidentate binding involving a d orbital of nueleophilic copper and π* and σ* orbitals of the substrate.

TL;DR: Uracil and thymine react with benzoyl chloride in acetonitrile-pyridine solution at room temperature to give first their 1- N -benzoyl (2b and 3b) and then their 1 − N, 3 − N -dibenzoyl derivatives (4a and 4b, respectively) under mild conditions of basic hydrolysis as mentioned in this paper.

TL;DR: A C 35 pentacyclic triterpenoid of the hopane series containing a thiophene ring, 30-(2′-methylene thienyl)-17β(H),21β (H)-hopane 1, has been confirmed in immature sediments by synthesis, suggesting incorporation of bacterial sulfur into geological organic matter at early stages of sedimentation as mentioned in this paper.

TL;DR: Enol triflates react with trialkylammonium formate-palladium reagent to give alkenes as discussed by the authors, which is a reagent that can be used to synthesize polycyclic polycyclohexadecane.

TL;DR: In this article, Lewis acid and hydroxyl protecting group were used for selective addition of crotyltri-n -butylstannane to either face of the aldehyde carbonyl in derivatives of 2-methyl-3-hydroxypropanal with preservation of erythro selectivity for the bond construction; allyl additions are limited to diastereofacial selectivity consistent with chelation control.

TL;DR: In this paper, the peroxide in the presence of (NH4)6Mo7O24 · 4H2O and potassium carbonate is a chemoselective method to oxidize secondary alcohols to ketones, the latter also accelerated by cerium chloride.

TL;DR: In this paper, new and efficient procedures are described for the conversion of homoallylic alcohols to esters of diazoacetic acid and for the further intramolecular cyclopropanation of those esters.

TL;DR: Trans-2,5-Bis(methoxymethyl)- and trans-2.5-bis(methyl)pyrrolidines proved to be excellent chiral auxiliaries for the asymmetric alkylation of the corresponding carboxyamide enolates giving good chemical yield and high stereoselectivity as discussed by the authors.

TL;DR: By proper choice of Lewis acid and protecting group, the Lewis acid mediated addition of allyltri-n -butylstannane to the α-hydroxyaldehyde derivatives 1b and 1c can be controlled to give excellent (95:5 to > 250:1) stereoselectivity for the formation of either erythro or threo products as mentioned in this paper.