合成路线1

4-Ethylpent-4-enoic acid (XXIV) is coupled to (R)-4-benzyl-2-oxazolidinone (XXV) via its mixed anhydride with pivaloyl chloride, producing the N-acyl oxazolidinone (XXVI). Diastereoselective cyanoethylation of (XXVI) with acrylonitrile leads to (XXVII). Reduction of imide (XXVII) with NaBH4, followed by protection of the resulting alcohol with t-butyldiphenylsilyl chloride furnishes the silyl ether (XXVIII). The nitrile function of (XXVIII) is then reduced by means of DIBAL to the aldehyde (XXIX), which is further treated with hydroxylamine to yield the corresponding oxime (XXX). Exposure of oxime (XXX) to NaOCl generates an intermediate nitrile oxide, which undergoes intramolecular 1,3-dipolar cycloaddition to the isoxazoline (XXXI). Subsequent reductive cleavage of the isoxazoline (XXXI) N-O bond with Zn/AcOH leads to compound (XXXII). Cyclohexanone (XXXII) is then converted to lactone (XXXIII) under Baeyer-Villiger conditions. Further methanolysis of lactone (XXXIII) gives rise to the open-chain dihydroxyester (XXXIV). Sequential protection of the primary hydroxyl group with triethylchlorosilane and the tertiary hydroxyl with trimethylchlorosilane furnishes the fully silylated triol (XXXV) (8). The lithium enolate of ester (XXXV) is then condensed with isothiocyanate (XXXVI) to produce thioanilide (XXXVII) (8, 9).