(20R) 3-oxo-18,20-oxydo (5alpha) pregname - and 3-alpha-N-dimethylamino-18,20-diacetoxy (5alpha) pregnane prepd in a multistage process from isofuntomidne

摘要

Iso ferntamidine (I) (prepd. by catalytic reduction of funtumidine is trifluoracetylated to give the O, N-di tri fluoracetyl deriv (II) which is hydrolysed to the 3 alpha-N-trifluoracetyl deriv (III) halogenated with hypoiodite to 3 alpha-N-triflu oroacetamido-18, 20-3xydo (5 alpha-pregnane (V), hydrolysed to give (20R) 3 alpha-amino-18, 20-oxydo (5 alpha) pregnane (VI) and finally oxidatively deaminated to (20R) 3 oxo-18, 20-oxydo-(5 alpha) pregnane (VI) is dimethylated then converted by the Jeger method to 3 alpha-N-dimethylamino-18, 20-diacetoxy (5 alpha) pregnane (VIII) and opt. hydrolysed to the diol. The corresponding -S-stereoisomer can be prepd. by a similar method.