๐”– Bobbio Scriptorium
โœฆ   LIBER   โœฆ

Divergent diastereoselectivity in the addition of nucleophiles to tetrahydrofuran-derived oxonium ions

โœ Scribed by Jared T Shaw; K.A Woerpel

Publisher
Elsevier Science
Year
1999
Tongue
French
Weight
676 KB
Volume
55
Category
Article
ISSN
0040-4020

No coin nor oath required. For personal study only.

โœฆ Synopsis

Alkyl substituted lactol acetates have been found to undergo highly stereoselective substitution reactions mediated by tin (IV) bromide. The highest selectivity is observed in the case of 4,4-di-isopropyl, 2-methyl substitution in which the selectivity depends on the nucleophile. Allyltrimethylsilane adds with high ( ) 1,2-syn selectivity while 2-methyl-trimethylsiloxy propene adds with high (>98:2) anti selectivity. These results can be rationalized through conformational analysis of the oxonium ion intermediate.

๐Ÿ“œ SIMILAR VOLUMES

Diastereoselection in the nucleophilic c
Diastereoselection in the nucleophilic conjugate addition of amines to 2-hydroxyalkylpropenoates
โœ P. Perlmutter; M. Tabone ๐Ÿ“‚ Article ๐Ÿ“… 1988 ๐Ÿ› Elsevier Science ๐ŸŒ French โš– 192 KB

Nucleophilic conjugate addition of benzylamine to 2-hydroxyalkylpropenoates la-c proceeds in high yield with modest diastereoselection. However, addition of benxylamine to the silyl ether of lc produces only the anti-isomer 2d in high yield Although nucleophilic conjugate additions of amines to 2-su