A new procedure for the enantioselective vinylogous aldol reaction of Chan’s diene
摘要:
Chiral delta-hydroxy-delta-ketoesters are easily available through the enantio selective vinylogous aldol reaction of Chan's diene promoted by a SiCl4/chiral phosphoramide catalytic system. The procedure is conveniently exploited for a very rapid approach to (+)-kavain, a natural bio-active alpha-pyrone compound. (c) 2007 Elsevier Ltd. All rights reserved.
methyl-3-hydroxy-5-phenylpentanoate and (6E)-ethyl 5-hydroxy-3-oxo-7-phenylhept-6-enoate is described in high enantiomeric excess and good yields. The effect of different lipases in different solvents has been screened using different acylating agents. This protocol has been extended for the preparation of enantiomerically pure biologically important kavalactones.
Chiral delta-hydroxy-delta-ketoesters are easily available through the enantio selective vinylogous aldol reaction of Chan's diene promoted by a SiCl4/chiral phosphoramide catalytic system. The procedure is conveniently exploited for a very rapid approach to (+)-kavain, a natural bio-active alpha-pyrone compound. (c) 2007 Elsevier Ltd. All rights reserved.