Methods for the preparation of Drospirenone and intermediates thereof

摘要

The invention relates to a process for the preparation of Drospirenone in high yields and purity starting from a compound of formula 2
wherein R is a hydroxyl protective group as defined in the claims, through a sequence of oxidation, deprotection, lactonization and water elimination steps, and wherein the steps of oxidation and lactonization are performed with 1,3,5-trichloro 1,3,5-triazine-2,4,6-(1H,3H,5H)-trione (trichloroisocyanuric acid, TCCA) or 1,3-dichloro-1,3,5-triazine-2,4,6-(1H,3H,5H)-trione (dichloroisocyanuric acid, DCCA) or an alkaline metal salt thereof such as the sodium salt dihydrate (DCCA sodium salt) or 1-hydroxyl,2-benziodoxol-3(777)-one 1-oxide (IBX). New synthetic intermediates useful for the synthesis of Drospirenone are disclosed, too.