Steroids and steroidases—XIX : Comparison of diazomethane and tiffeneau-demjanov homologations of 5α-3-oxosteroids. Evidence for predominant equatorial approach of the C-3 carbonyl group by diazomethane

Quantitative comparisons of the product ratios of the mechanistically similar diazomethane and Tiffeneau-Demjanov homologations of 17β-hydroxy-5α-androstan-3-one and 5α-cholestan-3-one have shown that equatorial approach of diazomethane to the C-3 CO group predominates to the extent of 70–79%. The data for both the C-17β-OH and -C₈H₁₇ substituted steroids are in close agreement thereby confirming that the C-17 substituents do not exert any significant long range effect on the reactions studied.