The oxidation of A-nor-5β-cholestan-3-one with peracids gave 4-oxa-5β-cholestan-3-one. This was identical with one of the two lactones produced by the reduction of Windaus' keto acid; the other lactone must be 4-oxa-5α-cholestan-3-one. The two lactones were reduced by lithium aluminum hydride to diols, which were cyclized to 4-oxa-5α- and -5β-cholestane.
A-nor-5β-cholestan-3-one 用过酸氧化得到 4-oxa-5β-cholestan-3-one。这与通过还原温道斯
酮酸产生的两种内酯之一相同;另一个内酯必须是 4-oxa-5α-cholestan-3-one。这两种内酯被
氢化铝锂还原成二醇,然后环化成 4-oxa-5α- 和 -5β-胆甾烷。