Stereoselective Synthesis of δ-Lactones from 5-Oxoalkanals via One-Pot Sequential Acetalization, Tishchenko Reaction, and Lactonization by Cooperative Catalysis of Samarium Ion and Mercaptan
作者:Jue-Liang Hsu、Jim-Min Fang
DOI:10.1021/jo016058t
日期:2001.12.1
sequence of acetalization, Tishchenko reaction and lactonization. The deliberative use of mercaptan, by comparison with alcohol, is advantageous to facilitate the catalytic cycle. The reaction mechanism and stereochemistry are proposed and supported by some experimental evidence. Such samarium ion/mercaptan cocatalyzed reactions show the feature of remote control, which is applicable to the asymmetric synthesis
Synthesis of the enantiomers of cis-2-methyl-5-hexanolide, the major component of the sex pheromone of the carpenter bee
作者:Kenji Mori、Shuji Senda
DOI:10.1016/s0040-4020(01)96497-x
日期:1985.1
and the enantiomers of methyl β-hydroxyisobutyrate. The specific rotations of our samples were [α]D±91.0-93.5° (CHCl3), while the reported values of the samples prepared by resolution or asymmetric synthesis were ±64.5–65.6°.
(2R,5S)-2-甲基-5-己内酯及其对映体以(S)-乳酸乙酯和β-羟基异丁酸甲酯的对映体为原料,以高光学纯度(⩾98-99%ee)合成。我们样品的比旋光度为[α] D ±91.0-93.5°(CHCl 3),而通过拆分或不对称合成制备的样品的报告值为±64.5–65.6°。
A Synthesis of Enantiomerically Pure (3<i>S</i>,6<i>R</i>)- and (3<i>R</i>,6<i>S</i>)-3,6-Dimethyltetrahydropyran-2-one
作者:Rosanna Bernardi、Dario Ghiringhelli
DOI:10.1055/s-1989-27436
日期:——
The title substances (3S,6R)-5 and 3R,6S)-5 were synthesized from enantiomerically pure (R)- and (S)-2-(2-hydroxypropyl)-1,3-dithiane (1), respectively, via a four-step sequence.