合成路线1

Grignard reagent (II), prepared from 1,4-dibromobutane (I), was added to lactone (III) to produce the cyclopentanol derivative (IV). Oxidation of the primary alcohol of (IV) with sulfur trioxide-pyridine complex in the presence of DMSO gave rise to lactone (V), which was reduced to the corresponding lactol (VI) by means of DIBAL at low temperature. Subsequent acid hydrolysis of the ketal group of (VI) afforded triol (VII). Mitsunobu coupling with 4-(diphenylmethoxy)-7-hydroxycoumarin (VIII) furnished ether (IX). After selective hydroxyl group protection of (IX) with chlorotriethylsilane to give (X), the remaining free hydroxyl was further protected as the tetrahydropyranyl ether (XI). Then, removal of the benzhydryl protecting group of (XI) was achieved by hydrogenation over Pd/C to give (XII).