Industrial process for the preparation of 17-hydroxy-6beta,7beta;15beta, 16beta-bismethylene-3-oxo-17alpha-pregn-4-ene-21-carboxylic acid y-lactone and key intermediates for this process

摘要

The invention relates to an industrial process for the preparation of 17-hydroxy-6β,7β;15β,16β-bismethylene-3-oxo-17α-pregn-4-ene-21-carboxylic acid γ-lactone of formula (I), and to the key-intermediates for this process.;