Synthesis of C-19-chiral steroids. Preparation of (19R); (19S) and (19RS)-3β-hydroxy[19-2H1,19-3H1] androst-5-en-17-ones
Abstract
The synthesis of the title compounds by two routes is described. The syntheses were based on the stereoselective reduction of 17,17-ethylenedioxy-3β-methoxy[19-3H] androst-5-en-19-als to (19R)- and (19S)-alcoho of high diastereoisomeric purities. The alcohols were converted, with retention, into the 19-iodides without loss of diastereoisomeric purity. The iodides were then hydrogenolysed, with inversion, to 19-chiral products.