An asymmetric synthesis of the furanocembrane (-)-bipinnatin J (3a) found in gorgonian corals is described. Treatment of 3a with VO(acaC)(2)-'BuOOH, followed by acetylation, gave acetoxypyranone 15. When 15 was heated in the presence of DBU, it underwent a transannular oxidopyrylium-alkene [5+2] cycloaddition producing the polycyclic diterpene (+)-intricarene 1, isolated from the coral Pseudopterogorgia kallos. The total synthesis of intricarene 1 mimics its most likely biosynthesis via oxidation of bipinnatin J (3a) in vivo. (c) 2006 Elsevier Ltd. All rights reserved.
Exploring Biosynthetic Relationships among Furanocembranoids: Synthesis of (−)-Bipinnatin J, (+)-Intricarene, (+)-Rubifolide, and (+)-Isoepilophodione B
作者:Paul A. Roethle、Paul T. Hernandez、Dirk Trauner
DOI:10.1021/ol062581o
日期:2006.12.1
The asymmetric total synthesis of (-)-bipinnatin J and itsconversion into (+)-intricarene through a transannular 1,3-dipolar cycloaddition is described. In addition, the conversion of (-)-bipinnatin J into (+)-rubifolide and (+)-isoepilophodione B is reported. Biosynthetic relationships among furanocembranoids and the possible role of 1,3-dipolar cycloadditions in biosynthesis are discussed. [reaction: