Lithium Hydroxide → 6-(1,3-Dihydro-6-hydroxy-7-methyl-3-oxo-4-p-toluenesulfonyloxyisobenzofuran-5-yl)-4-methyl-4-hexenoic acid

Participants

Reaction Steps

A solution of methyl (E) 6-(1,3-dihydro-6-ethyl-7-methyl-3-oxo-4-p-toluenesulfonyloxylisobenzofuran-5-yl)-4-methyl-4-hexenoate (3.16 g) and lithium hydroxide (1.2 g) in 1:1 aqueous methanol (40 ml) was heated at 62° C. for 18 hours. The solution was acidified and extracted with ethyl acetate. The extract was dried and evaporated and the residue chromatographed on silica gel, eluting wth ethyl acetate/hexane/acetic acid to afford (E) 6-(1,3-dihydro-6-ethyl-4-hydroxy-7-methyl-3-oxoisobenzofuran-5-yl)-4-methyl-4-hexenoic acid, m.p. 141°-142° C. (t-butylmethylether).

Provenance & Evidence