Zur Synthese des Ecdysons. IV. Mitteilung über Insektenhormone. Die Synthese des natürlichen Häutungshormons

Ecdysone ( 9 ), a hormone responsible for the skin shedding process of arthropoda , has been synthesized. (20 S )‐2β,3β‐Diacetoxy‐20‐formyl‐5β‐pregn‐7‐en‐6‐one was prepared from the corresponding carboxylic acid and converted into ecdysone by a G RIGNARD reaction with 2‐methyl‐3‐butyn‐2‐ol tetrahydropyran‐2‐yl ether, followed by hydrogenation of the triple bond, removal of the protecting groups, and hydroxylation in the 14α‐position. C‐22‐isoecdysone was obtained as a by‐product.