反应详情

A mixture of 1.0 g (3.48 mmoles) of rac.-6-acetyloxy-3,4-dihydro-2,5,7,8-tetramethyl-2H-1-benzopyran-2-acetonitrile, 1.0 g (15.2 mmoles) of 85% KOH, 1 ml of water and 8 ml of ethylene glycol was stirred and refluxed for 16 hr. The reaction mixture was cooled to room temperature, then poured into water. The pH of the solution was adjusted to 8 with 1 N aqueous HCl. The resulting mixture was extracted with two portions of ether (the ether extracts were discarded). The aqueous phase was acidified with 3 N aqueous HCl and worked-up with ether in the usual manner giving 756 mg (82%) of rac.-(6-hydroxy-3,4-dihydro-2,5,7,8-tetramethyl-2H-1-benzopyran-2-yl)acetic acid as a tan solid.

1. temperaturerefluxed for 16 hr
2. extractionThe resulting mixture was extracted with two portions of ether (the ether extracts