Steroids having an α-spiro β-methylene γ-lactone structure, (3R) and (3S)-4'-methylenedihydrospiro-[5α-cholestane-3, 3'(2'H)-furan]-2'-one, were synthesized from 5α-cholestan-3-one by means of the Knoevenagel reaction, conjugated addition of a cyanide ion, reduction of ester groups, hydrolysis and dehydration.