A new class of recoverable chiral sulphoxide: Application to the asymmetric synthesis of β-hydroxy esters.
作者:Martin Wills、Roger J. Butlin、Ian D. Linney
DOI:10.1016/s0040-4039(00)79112-x
日期:1992.9
Enantiomerically pure cyclic sulphinadime S(S)R-(+)-2 was prepared from homochiral sulphinic acid R-(−)-1 and subsequently converted to the ester S(S)R-(−)-3 via ring opening with an ester enolate. Aldol reactions of S(S)R-(−)-3 with aromatic aldehydes gave, with one exception, aldol products4 in high diastereoisomeric excess. Reductive cleavage of the aldol adducts4 gave β-hydroxy esters5 in high
对映体纯的环状磺胺嘧啶S (S) R-(+)- 2由高手性亚磺酸R-(-)- 1制备,随后通过开环将其转化为酯S (S) R-(-)- 3。酯烯酸酯。S (S) R-(-)- 3与芳族醛的醛醇缩合反应,除一种例外,是高非对映异构体过量的醛醇缩合产物4。醛醇加合物4的还原裂解得到高(> 95%)对映异构体过量的β-羟基酯5和可以再循环至S (S) R-(+)- 2的硫醇6。因此,S (S)R-(+)- 2代表可回收手性亚砜的来源。