A practical enantioselective total synthesis of the bengamides B, E, and Z.
[reaction: see text] A practical total synthesis of Bengamides B, E, and Z from a common polyol intermediate is described. Consecutive aldol condensations afford a protected polyol thioester side chain suitable for coupling to the Bengamides. A novel chiral phase transfer catalyzed enantioselective alkylation affords the more highly functionalized amino caprolactams required for Bengamides B and Z. Use of the 2-naphthylmethyl ether protecting group, compatible with the boron Lewis acids required for enantioselective aldol condensation, allows direct access to Bengamide B.
Boeckman
Robert K
RK
Department of Chemistry, University of Rochester, Rochester, New York 14627-0216, USA. rkb@rkbmac.chem.rochester.edu
Clark
Tammy J
TJ
Shook
Brian C
BC
D000970:Antineoplastic Agents / Q000138:chemical synthesis* / Q000737:chemistry; D001381:Azepines / Q000138:chemical synthesis* / Q000737:chemistry*; D013237:Stereoisomerism
D000970:Antineoplastic Agents; D001381:Azepines; C460180:bengamide Z; C427480:bengamide B; C427481:bengamide E