Patent ID: 8242288

Claim:
A method of preparing a (6R)-3-hexyl-4-hydroxy-6-undecyl-5,6-dihydropyran-2-one of formula (I), which comprises: 1) subjecting a compound of formula (II) to a reaction with a compound of formula (III) in the presence of zinc; 2) treating a resulting reaction mixture with an aqueous acid to produce a precipitate; 3) washing the precipitate with an organic solvent to obtain an organic layer; and 4) subjecting the organic layer to a cyclization under an acidic condition to obtain (6R)-3-hexyl-4-hydroxy-6-undecyl-5,6-dihydropyran-2-one of formula (I): wherein, P′ is hydrogen or a protecting group selected from trialkylsilyl and alkoxyalkyl which can be deprotected under an acidic condition, and R is methyl, ethyl, or propyl.