Michael R Flavin

US Patent:

54896975, Feb 6, 1996

Filed:

Aug 3, 1994

Appl. No.:

8/285655

Inventors:

William A. Boulanger - Schenectady NY
Michael T. Flavin - Darien IL
Alla Kucherenko - Lemont IL
Abram K. Sheynkman - Lemont IL

Assignee:

MediChem Research, Inc. - Lemont IL

International Classification:

C07D31178
C07D31176

US Classification:

549278

Abstract:

A method for preparing (. +-. )-calanolide A, 1, a potent HIV reverse transcriptase inhibitor, from chromene 4 is provided. Useful intermediates for preparing (. +-. )-calanolide A and its derivatives are also provided. According to the disclosed method, chromene 4 intermediate was reacted with acetaldehyde diethyl acetal in the presence of an acid catalyst with heating to produce chromanone 7. Reduction of chromene 7 with sodium borohydride, in the presence of cerium trichloride, produced (. +-. )-calanolide A, which was purified chromatographically.