合成路线1

Opening of the (S,S)-epoxide (I) with the silylmethyl Grignard reagent (II) in the presence of CuI, followed by oxidative cleavage of the silyl alcohol (III) with H2O2 gave diol (IV). Then, selective protection of the primary hydroxyl group of (IV) with tert-butyldimethylsilyl chloride, followed by condensation with methanesulfonyl chloride, afforded mesylate (V). Subsequent alkylation of the sodium salt of ethyl mercaptoacetate (VI) gave thioether (VII). Desilylation of (VII) with tetrabutylammonium fluoride, followed by mesylation provided sulfonate (VIII). Subsequent intramolecular ring closure of (VIII) using NaH in DMF produced the tetrahydrothiophene (IX) as a 2:3 mixture of stereoisomers. Hydrolysis of the ethyl ester of (IX) with LiOH gave carboxylic acid (X), which was submitted to a modified Hunsdiecker reaction with Pb(OAc)4 to furnish the 1-O-acetate (XI) as a 1:1 anomeric mixture.