Abstract
N-Sulfonylated 3-methoxycholestane (5→3)-lactams (Vc), (VIc) and (VId) were subjected to reductive fragmentation initiated with lithium aluminum hydride giving in good yields N-sulfonylated cis-amino alcohols (3α, 5α and 3β, 5β) (XIIIa), (XIVc), and (XIVa). These compounds were smoothly cyclized to 3α, 5-iminomethano-5α-and 3β, -5-iminomethano-5β-cholestane derivatives, (Ia), (IIa), and (IIb), which were then desulfonylated to give 3α, 5α-and 3β, 5β-pyrrolidinocholestanes (Ib) and (IIc), respectively.
