Veratrole → 5,6-Dimethoxy-3-methyl-2,3-dihydro-1H-inden-1-one

Participants

Reaction Conditions

Reaction Steps

A mixture of 1,2-dimethoxy-benzene (Compound 47a) (19.1 mL, 0.150 mole) and but-3-enoic acid (Compound 49a) (19.2 mL, 0.225 mole) was stirred under argon in an ice bath. Polyphosphoric acid (230 g, 1.05 mole) was added slowly. After addition was complete, the ice bath was removed and the reaction heated for 16 hours at 60° C. The reaction was added to ice water and extracted with ether. The organic extracts were washed with 3N NaOH, water, brine and dried over Na2SO4. The solvent was then removed in vacuo to yield a yellow solid containing a racemic mixture of the title compounds. The crude material was purified on a silica gel column using 1:2 EtOAc:hexane as the eluents. The pure fractions were combined and concentrated to yield the racemic mixture of the title compound (Intermediate X) as an off-white solid.

Provenance & Evidence