1.
J Org Chem
; 69(19): 6335-40, 2004 Sep 17.
Artigo
em Inglês
| MEDLINE
| ID: mdl-15357593
RESUMO
The first example of an asymmetric intramolecular Michael addition reaction with use of alpha-lithiated vinylic sulfoxide as a Michael donor is reported. Michael addition of the alpha-lithiated vinylic sulfoxide to (Z)-enoates proceeds with high diastereoselectivity to give the adducts with (R)-configuration at the beta-position of the ester in the five-membered-ring formation. The selectivity was reversed in the six-membered-ring formation. The resulting ester enolates were reacted with alkyl halides or benzaldehyde with high diastereoselectivity.