反应详情

To a stirring solution of 3 (9.342 g, 40 mmol) in acetone (115 mL) in a flame dried round bottom flask under an inert atmosphere was added 2,2-dimethoxypropane (66 mL). To this solution was added BF3.OEt2 (0.30 mL, cat.) and stirring was continued at rt for 2 h. The reaction mixture was then concentrated in vacuo to an orange oil which was purified by flash chromatography to provide 4 (9.392 g, 85%) as a white solid. Rf=0.55 (1:3 EtOAc/hexanes). Compound was observed as an uneven mixture of rotomers.

1. concentrationThe reaction mixture was then concentrated in vacuo to an orange oil which
2. customwas purified by flash chromatography