Oxidative cyclization and fragmentation of steroidal alcohols induced by ceric ammonium nitrate
作者:Venkataraman Balasubramanian、Cecil H. Robinson
DOI:10.1016/s0040-4039(01)90139-x
日期:——
Oxidative cyclizations of steroidal alcohols (1a–1d) using cericammoniumnitrate (CAN) in aqueous acetonitrile or aqueous acetic acid gave the corresponding cyclic ethers (2a–2d), whereas the tertiary alcohol (4) gave secosteroid (5).
Methods are described for effecting the molecular rearrangement of 3β-acetoxy-4aα-hydroxy-5β-methyl-A-homo-B-nor steroids into corresponding normal structures of the 6-methylene-5β-H series. NMR spectral data lead to the assignment of the α-configuration to the 4a-hydroxyl group present in the initial steroidal A-homo-B-nor types.
6-Hydroxy and 6-oxo-androstane derivatives having the general formula (I):
wherein the symbol represents a single or a double bond and A, R1 and R2 have the meanings given in the description; a pharmaceutical composition comprising the same and their use for the preparation of a medicament useful for the treatment of cardiovascular disorders such as heart failure and hypertension are disclosed.