Prostaglandins: a novel synthesis of ±-PGF1αvia cyclopentane-1,3-dione derivatives

Abstract

An efficient synthesis of PGF_{1 α}via cyclization of an easily available acyclic precursor is described. Thus, alkylation of ethyl acetoacetate with ethyl α-iodo-oleate to give (1), followed by cyclization with LDA, provided an expeditious route to the cyclopentanedione (2). Sequential protection by means of ethylene glycol and selective deprotection of (2) afforded the monoacetal (4) in good yield. Stereospecific reduction of (4) by L-Selectride, followed by deacetalization and stereospecific reduction with NaBH₄, efficiently furnished the derivative (8). Oxidative cleavage of the side-chain of (8) after protection of the hydroxy group with dihydropyran led in good yield to compound (10), which was converted into PGF_1α according to literature procedures