4-Pregnene-3,20-dione-21-ol benzoate → 4,9(11)-Pregnadiene-3,20-dione-21-ol benzoate

Participants

Reaction Steps

The process described for the preparation of 4-pregnene-3,20-dione-21-ol benzoate (see the further-conversion of the product described in Example 4) is followed by using 4.97 g (9.7 mmoles) of 21-benzoyloxy-4,9(11)-pregnadiene-3,20-dione-3-ethylenedithioacetal as starting material [prepared as described in the preceding Step (a)], except that the crude product is not subjected to chromatography, but it is recrystallized from ethyl acetate under purifying with activated carbon to give 1.8 g (42% yield) of the aimed product, m.p.: 176°-177° C., [α]D =+175.1° (c=1 in chloroform).

Provenance & Evidence