反应详情

Treatment of (±)-3-[2-(benzyloxy)-5-chloro-3-methoxyphenyl]-1,2-propanediol (32 g, 0.1 mol) with p-toluenesulfonyl chloride (21 g, 0.11 mol) in pyridine generally according to the procedure described for intermediate 3 provided (±)-3-[2-(benzyloxy)-5-chloro-3-methoxyphenyl]-2-hydroxypropyl 4-methylbenzenesulfonate. Treatment of the tosylate with palladium on carbon (2.32 g, 5 wt. %) generally according to the procedure described for Intermediate 4 afforded (±)-3-(5-chloro-2-hydroxy-3-methoxyphenyl)-2-hydroxypropyl 4-methylbenzenesulfonate. Treatment of the phenol with triphenylphosphine (23.6 g, 0.09 mol) and diisopropyl azodicarboxylate (18.2 g, 0.09 mol) generally according to the procedure described for Intermediate 5 afforded 28 g (76%) of (±)-(5-chloro-7-methoxy-2,3-dihydro-1-benzofuran-2-yl)methyl 4-methylbenzenesulfonate as a pale yellow solid. mp 99-102° C.; Anal. calcd. for C17H17ClO5S: C, 55.36; H, 4.65. Found: C, 55.35; H, 4.62.