(+)-(R,Z)-5-Muscenone and (-)-(R)-muscone by enantioselective aldol reaction and Grob fragmentation.
(+)-(R,Z)-5-Muscenone ((R)-1) was synthesized by an enantioselective aldol reaction, catalyzed by new ephedrine-type Ti reagents (up to 70 % enantiomeric excess). Substrate-directed diastereoselective reduction of the aldol product and Grob fragmentation of the tosylate of the resultant 1,3-diol afforded (+)-1. This approach also gave access to (-)-(R,E)-5-muscenone and (-)-(R)-muscone.
Fehr
Charles
C
Firmenich SA, Corporate R&D Division, P.O. Box 239, 1211 Geneva 8, Switzerland. charles.fehr@firmenich.com
Buzas
Andrea K
AK
Knopff
Oliver
O
de Saint Laumer
Jean-Yves
JY