Synthesis of (3a S- cis)-(−)- and (3a R- cis)-(+)-debromoflustramine B

A synthesis of the (3a S- cis)-(−)- and (3a R- cis)-(+)-enantiomers of debromoflustramine B 1 is reported. The synthesis involves the chromatographic separation of the corresponding (−)- and (+)- N-phenylethyl lactams 10 and 11, obtained by the reaction of racemic lactone 6 with ( S)-(−)-1-phenyleth...

Full description

Saved in:
Bibliographic Details
Published in:Tetrahedron: asymmetry 2005-07, Vol.16 (14), p.2493-2499
Main Authors: Morales-Ríos, Martha S., Rivera-Becerril, Ernesto, Joseph-Nathan, Pedro
Format: Article
Language:English
Citations: Items that this one cites
Items that cite this one
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:A synthesis of the (3a S- cis)-(−)- and (3a R- cis)-(+)-enantiomers of debromoflustramine B 1 is reported. The synthesis involves the chromatographic separation of the corresponding (−)- and (+)- N-phenylethyl lactams 10 and 11, obtained by the reaction of racemic lactone 6 with ( S)-(−)-1-phenylethylamine, followed by hydrolysis to give both enantiomers of 6 with very high enantiomeric excesses. The lactamization of (−)- 6 gives (−)- 7, which was converted to (−)- 1 by reduction with LiAlH 4 without racemization. Optically active (+)- 1 was similarly prepared from (+)- 6. The absolute configurations were established by comparison with the known negative Cotton effect of (3a S- cis)-(−)-physostigmine.
ISSN:0957-4166
1362-511X
DOI:10.1016/j.tetasy.2005.06.022