Winkler JD.
*
Doherty EM.
The University of Pennsylvania, Philadelphia, USA
The First Total Synthesis of (±)-Saudin.
J. Am. Chem. Soc. 1999;
121: 7425-7426
Key words
(±)-saudin - [2+2] cycloaddition - Stille cross-coupling - Michael addition–aldol
addition cascade
Significance
Saudin is a diterpenoid that was isolated from Cluytia richardiana in 1985. It possesses a highly oxidized rearranged labdane skeleton and exhibits
potent noninsulin dependent hypoglycemic activity. In 1999, Winkler and Doherty reported
the first total synthesis of (±)-saudin by photochemical [2+2] cycloaddition of diene
I.
Comment
A Michael addition–aldol addition cascade of A and B afforded C. Irradiation of I gave cyclobutane J as a single diastereomer. The furyl substituent was introduced by ketene acetal triflate
formation and Stille cross-coupling. The natural product was obtained by treating
M first with aqueous base and then with acid.
