Lithium hydroxide, monohydrate → HCID 67754673, compound

Participants

Reaction Steps

A solution of methyl (E)-6-(1,3-dihydro-4-isocyanato-6-methoxy-7-methyl-3-oxoisobenzofuran-5-yl)-4-methyl-4-hexenoate (1.0 g) in 10 ml methanol was heated to reflux for 4 hours and then evaporated to dryness. The residue was recrystallized from acetone/hexane to give 0.41 g of methyl (E)-6-(1,3-dihydro-4-methoxycarbonylamino-6-methoxy-7-methyl-3-oxoisobenzofuran-5-yl)-4-methyl-4-hexenoate. The ester (0.35 g) and 0.05 g of LiOH-H2O in 9 ml 2:1 MeOH-H2O was heated at reflux for 4 hours. The mixture was acidified, extracted with ethyl acetate, and the organic layer was dried over MgSO4. The organic layer was concentrated and the residue was further purified by silica gel chromatography (eluant 60:40:2 hexane:ethyl acetate:acetic acid) to give 0.21 g of (E)-6-(1,3-dihydro-4-methoxycarbonylamino-6-methoxy-7-methyl-3-oxoisobenzofuran-5-yl)-4-methyl-4-hexenoic acid, mp 155°-158° C.

Provenance & Evidence