1.
Proc Natl Acad Sci U S A
; 82(7): 1879-80, 1985 Apr.
Article
in English
| MEDLINE
| ID: mdl-3856866
ABSTRACT
The total synthesis of a typical 11-hydroxylated steroid, (+/-)-11 alpha-hydroxyprogesterone, was achieved by picric acid-catalyzed tricyclization of a polyunsaturated epoxide appropriately substituted with ketal, hydroxyl, and acetylenic units. This epoxide was prepared by a multistage sequence featuring two successive alkylations of intermediary, monocyclic sulfones. The first sulfone intermediate was obtained by means of a short sequence starting from levulinic acid and diethyl succinate and involving a selective cyclization reaction.