合成路线1

The reduction of ethylene ketal (XXI) with LiAlH4 produces the hydroxymethyl compound (XXII), which by selective tosylation with tosyl chloride yields the tosyloxymethyl compound (XXIII). The cyclization of (XXIII) with NaH in DMF affords the epoxy methane derivative (XXIV), which is deprotected by treatment with piruvic acid (D) in THF to give 2-(3-hydroxy-1-octen-1-yl)-3,5-epoxymethanocyclopentane-1-carboxaldehyde (XXV). The selective protection of the hydroxyl group of (XXV) with ethyl vinyl ether (E) affords the 1-ethoxyethoxy compound (XXVI), which is submitted to homologation in the aldehyde group by treatment with methoxymethylene-triphenylphosphorane (F) and butyllithium in THF, followed by hydrolysis of the non-isolated enol ether with mercuric acetate - water to give the acetaldehyde homolog (XXVII). The Wittig reaction of (XXVII) with 4-carboxybutyltriphenylphosphonium chloride (G) and NaH in DMSO yields 9,11-dideoxy-11alpha,9alpha-epoxymethano-15-(1-ethoxyethoxy)-PGE2 (XXVIII), which is finally deprotected by treatment with acetic acid in THF-water.