合成路线1

1,4-Benzenedimethanol (I) was monoprotected with tert-butyldimethylsilyl chloride in the presence of imidazole, and the resulting silyl ether (II) was oxidized with MnO2 in refluxing THF to aldehyde (III). This was treated with 3-lithiopyridine (IV), (generated from 3-bromopyridine and butyllithium at -78 C in Et2O), to give carbinol (V), which was oxidized with MnO2 to ketone (VI). Wittig reaction with 5-carboxypentylphosphonium bromide (VII) and t-BuOK in THF at low temperature yielded a 4:1 mixture of Z and E heptenoic acids (VIII). Subsequent reaction with diazomethane provided a mixture of esters, from which the E isomer (IX) was separated by column chromatography. Oxidation of TBDMS ether with Jones reagent provided acid (X), and this was coupled with N-(4-cyclohexylbutyl)-L-serinamide (XI) using N-(dimethylaminopropyl)-N'-ethylcarbodiimide.HCl (EDC) in the presence of HOBT and N-methylmorpholine to give amide (XII). Cyclization to oxazolidine (XIII) was effected by treatment with triphenyl phosphine and diisopropylethylamine.