A Concise Synthesis of R-(-)-Cicutoxin, a Natural 17-Carbon Polyenyne.

ABSTRACT: A concise synthesis of the natural polyenyne R-(-)-cicutoxin (1) is described. After several trials, the successful synthesis commenced with three key fragments, R-(-)-1-hexyn-3-ol (8), 1,4-diiodo-1,3-butadiene (9), and the THP protected 4,6-heptadiyn-1-ol (6). Sonogashira coupling of compound 9 with acetylenes 6 and 8 gave the 17-carbon frame, which upon regio-selective reduction of a triple bond with red Al and removal of the THP protecting group afforded the natural product in four linear steps. The triply convergent synthesis gave R-(-)-cicutoxin in 18% overall yield.

SUBMITTER: Gung BW 

PROVIDER: S-EPMC3835075 | biostudies-literature | 2009 Mar

REPOSITORIES: biostudies-literature