The migration of C-2 and/or C-4 to O or N in the Beckmann, Schmidt, and Baeyer-Villiger reactions of 3-keto steroids has been studied with the aid of 13Cmr spectroscopy. Authentic specimens of the eight possible lactone and lactam products from both 5α-and 5β-cholestan- 3-one have been prepared; their physical properties and 13Cmr assignments are given. Seven ring expansion reactions reported to give only one product have been found to give ...