Convenient Synthesis of Enantiomerically Enriched (Oxybutenyl)stannanes and Their Lewis Acid Catalyzed Homoaldol Reactions
- 1 January 1996
- journal article
- research article
- Published by Georg Thieme Verlag KG in Synthesis
- Vol. 1996 (01) , 141-144
- https://doi.org/10.1055/s-1996-4172
Abstract
(E)-But-2-enyl N,N-diisopropylcarbamate10 (5), after deprotonation to its lithium/(-)-sparteine complex 6, yields with trialkyltin chlorides mixtures of the 3-oxy- and 1-oxy-substituted, enantiomerically enriched allylstannanes (S)-8 and (R)-9. (R)-8 is obtained with high regioselectivity and enantiomeric purity (95% ee) via a delithiotitanation (inversion) and detitanostannylation (anti-SE’)sequence. The titanium tetrachloride mediated condensation of (S)- or (R)-8 with aldehydes or ketones proceeds via titanodestannylation to yield (Z)-anti-homoaldol products 11 with complete chirality transfer.Keywords
This publication has 0 references indexed in Scilit: