A new type of chiral sulfoniumsalts that are characterized by a bicyclic system has been designed and synthesized from α‐amino acids. Their corresponding ylides, which were prepared by basic treatment of the sulfoniumsalts, reacted smoothly with a broad array of simple and chiral aldehydes to provide trans‐epoxy amides in reasonable to very good yields and excellent stereoselectivities (>98 %). The
Synthetic studies on a marine polyether toxin, gambierol: stereoselective synthesis of the EFGH ring system via B -alkyl Suzuki coupling
作者:Haruhiko Fuwa、Makoto Sasaki、Kazuo Tachibana
DOI:10.1016/s0040-4020(01)00164-8
日期:2001.4
A synthetic route to the EFGH ring system (3) of gambierol (1), a marine polyethertoxin isolated from the dinoflagellate Gambierdiscus toxicus, has been developed. The present synthesis features convergent coupling of the F and H rings followed by ring-closure of the G ring based on the B-alkyl Suzuki reaction of lactone-derived enol phosphates. An angular methyl group at C23 was stereoselectively