反应详情

A stirred, cooled (ice bath) solution of 6-bromo-2,2,4,4-tetramethyl chroman, (0.5 g, 1.865 mmol) in anhydrous dichloromethane (5 mL) was treated with a 1M solution (1.86 mL, 1.86 mmol) of titanium tetrachloride in dichloromethane followed by α,α-dichloro methyl ether (0.214 g, 1.865 mmol). The reaction mixture was allowed to warm to ambient temperature for 4 h. The reaction mixture was diluted with diethyl ether, washed with brine (×1) and dried over anhydrous sodium sulfate, filtered and evaporated in vacuo to a residue which was subjected to flash column chromatography over silica gel (230-400 mesh) using 5% ethyl acetate in hexane to afford the title compound as a yellow solid (0.52 g, 94%).

1. washwashed with brine (×1)
2. dry with materialdried over anhydrous sodium sulfate
3. filtrationfiltered
4. customevaporated in vacuo to a residue which