11-Dehydrosteroids - intermediates

Process:- R = a (1-10 C) hydrocarbon residue, e.g. pMe.C6H4-; S = the residue of the (opt. subst.) steroid nucleus Both base and solvent must be non-hydroxylic e.g. NaOMe/D.M.F., MeLi/PhH. Pharmaceutical intermediates. (a) MeSO2NHNH2 (2.0 g.) was added to hecogenin acetate (4 g.) in AcOH (90 ml.) at 40 deg., stirred overnight at 20 deg., and filtered, giving (II) (1.33 g.), m.p. 260-3 deg. (d.). A further 3.42 g. were obtained from the mother liquors. (b) The hydrazone (0.5 g.) was heated over 10 mins., to 150 deg., with NaOMe (0.4 g.) in DMF (10 ml.), kept 26 mins. at 150 deg., cooled and pptd. with H2O (100 ml), giving the 11-ene (378 mg.).