| abstract |
(17R)-Spiro-[androstane-17,1'-cyclobutan]-2'-ones are prepared by the reaction of a 17-oxo androstane, wherein all other ketones are blocked, with a cyclopropylarylsulfide or with a cyclopropylarylsulfonium salt having a non-nucleophilic anion, in an organic solvent together with a strong base, followed by reaction in situ of the intermediate thereby formed with aqueous acid or water. n Some (17R)-spiro-[androstan-17,1'-cyclobutan]-2'-ones are useful as intermediates in preparing (17R)-spiro-[3-oxo-4-androstene-17,1'-cyclobutan]-2'-ones which are aldosterone antagonists. Additionally, (17R)-spiro-[androstane-17,1'-cyclobutan]-2'-ones are useful as intermediates in preparing known 17α-pregnane-21,17β-carbolactones, valuable aldosterone blocking agents. |