[Steroidal heterocyclic compounds: [16,15-c]-pyrazole derivatives of estradiol and of estrone]. / Eterociclici steroidali: [16,15-c]-pirazolderivati dell'estradiolo e dell'estrone

Condensation between ethyl formate and estradiol 16-keto derivatives, in which the 17beta-hydroxyl groups had been protected as tetrahydropyranyl ethers, produced the corresponding 15-hydroxymethylene compounds. These, by cyclization with hydrazine, gave the [16,15-c]-pyrazole derivatives. Further reactions, such as hydrolysis, etherification and chromic oxidation, afforded many differently substituted [16,15-c]-pyrazoles of the estradiol and estrone series.