合成路线1

Mono-protection of 1,4-butanediol (XI) by means of 4-methoxybenzyl chloride, followed by Swern oxidation with DMSO/SO3-Pyr, leads to the aldehyde (XII). Condensation of (XII)with the boron enolate of the N-propionyl oxazolidinone (III) and subsequent silylation with tert-butyldimethylsilyl triflate furnishes the N-acyl oxoazolidinone (XIII), which is reduced by LiBH4 to the primary alcohol (XIV), which is then subjected to Swern oxidation to produce the aldehyde (XV). Further condensation of (XV) with acyl oxazolidinone (III) leads to adduct (XVI). The free hydroxyl group of (XVI) is alkylated with chloromethyl methyl ether to produce the O-methoxymethyl derivative (XVII), which under desilylation conditions with HF-pyridine cyclizes to the lactone (XVIII).