The solid diastereoisomeric mixture 4a+4b was obtained via the asymmetric Michael addition reaction of phenylthioalcohol with liquid epimeric mixture 5\|( )\|bornyloxy\|2(5H)\|furanone 3a+3b, which was prepared by rea...The solid diastereoisomeric mixture 4a+4b was obtained via the asymmetric Michael addition reaction of phenylthioalcohol with liquid epimeric mixture 5\|( )\|bornyloxy\|2(5H)\|furanone 3a+3b, which was prepared by reaction of the natural abundant chiral auxiliary borneol 2 with 5\|hydroxy\|2(5H)\|furanone 1. The two diastereoisomers 4a+4b were separated by means of preferential cyrstallization, which gave one optically pure compound 4b with de>98%. The absolute configuration of 4b was established by X\|ray crystallography. The method provided a new efficient route for utilizing natural chiral auxiliaries and preparing optically pure diastereoisomeric compounds based on liquid epimers.展开更多
文摘The solid diastereoisomeric mixture 4a+4b was obtained via the asymmetric Michael addition reaction of phenylthioalcohol with liquid epimeric mixture 5\|( )\|bornyloxy\|2(5H)\|furanone 3a+3b, which was prepared by reaction of the natural abundant chiral auxiliary borneol 2 with 5\|hydroxy\|2(5H)\|furanone 1. The two diastereoisomers 4a+4b were separated by means of preferential cyrstallization, which gave one optically pure compound 4b with de>98%. The absolute configuration of 4b was established by X\|ray crystallography. The method provided a new efficient route for utilizing natural chiral auxiliaries and preparing optically pure diastereoisomeric compounds based on liquid epimers.