(R)-1,3-dimethylcyclopropene—one isomer of the smallest chiral hydrocarbon
摘要:
1-Lithio-1,3-dimethylcyclopropene has been obtained in optically active form in five steps from tiglic acid and trapped with electrophiles to produce, among others, optically active 1,3-dimethylcyclopropene.
Structure and Conformation ofβ-Oligopeptide Derivatives with Simple Proteinogenic Side Chains: Circular Dichroism and Molecular Dynamics Investigations
A Straightforward Synthesis of Polyketides via Ester Dienolate Matteson Homologation
作者:Oliver Andler、Uli Kazmaier
DOI:10.1002/chem.202004650
日期:2021.1.13
for the stereoselective synthesis of highly substituted α,β‐unsaturated δ‐hydroxy carboxyl acids, structural motifs widespread found in polyketide natural products. The protocol is rather flexible and permits the introduction of substituents and functionalities also at those positions which are not accessible by the commonly used aldol reaction. Therefore, this ester dienolate Matteson approach is an
Préparation des organozinciques dérivés de l'α-bromométhyl acrylate d'éthyle et de ses homologues
作者:Najat El Alami、Chantal Belaud、Jean Villiéras
DOI:10.1016/0022-328x(88)80333-4
日期:1988.6
α-bromoalkyl acrylates (aliphatic and alicyclic) results in high yields when carried out on 30 mesh activated granular zinc, between 14 and 20°C in ethereal solvents (THF, DME, ether). Under these conditions duplication can be minimized (5–15%) especially with t-butyl acrylates. These α-functional allylic organozinc derivatives have been characterized by hydrolysis and coupling with benzaldehyde.
Stereoselective Synthesis of a Protected Side Chain of Meliponamycin A
作者:Oliver Andler、Uli Kazmaier
DOI:10.1021/acs.orglett.2c00701
日期:2022.4.8
The Matteson homologation was found to be a versatile tool for the construction of the linear polyketide sidechain of meliponamycin and related compounds in only four steps. The ester dienolate version of this reaction allowed the introduction of the unsaturated ester moiety in a highly stereoselective fashion. Boronate oxidation/deoxygenation and Sharpless dihydroxylation are additional key steps
Davies, Stephen G.; Ichihara, Osamu; Walters, Iain A. S., Journal of the Chemical Society. Perkin transactions I, 1994, # 9, p. 1141 - 1148
作者:Davies, Stephen G.、Ichihara, Osamu、Walters, Iain A. S.
DOI:——
日期:——
Asymmetric synthesis of α-amino carbonyl derivatives using lithium (R)-N-benzyl-N-α-methylbenzylamide
作者:Stephen G. Davies、Simon W. Epstein、A.Christopher Garner、Osamu Ichihara、Andrew D. Smith
DOI:10.1016/s0957-4166(02)00406-8
日期:2002.8
An efficient protocol for the transformation of homochiral alpha-hydroxy-beta-amino esters to their alpha-amino carbonyl components is presented. Diastereoselective conjugate addition of lithium (R)-N-benzyl-N-alpha-methylbenzylamide to a range of alpha,beta-unsaturated esters and subsequent enolate hydroxylation with (1R)-(-)-(camphorsulfonyl)oxaziridine, followed by LiAlH4 reduction produces homochiral 3-amino-1,2-diols. Subsequent oxidative cleavage with H5IO6 provides N-benzyl-N-alpha-methylbenzyl protected alpha-amino aldehydes (96-98% d.e.) and ketones (88% d.e.). Further oxidation of the alpha-amino aldehydes with sodium chlorite and Pd-catalysed hydrogenation provides alpha-amino acids in 94-98% e.e. (C) 2002 Elsevier Science Ltd. All rights reserved.