反应详情

A solution of 6-nitro-2,2-dimethyl-3-(trifluoroacetamido)methyl-2H-1-benzopyran (0.5 g, 1.52 mmol) in dichloromethane (10 ml) at 0° C. was treated with m-chloroperbenzoic acid (70%, 0.45 g, 1.52 mmol). After stirring for sixteen hours at room temperature, water and sodium hydrogen carbonate were added and the organic phase separated and evaporated under reduced pressure. The residue was chromatographed on silica gel, eluting with dichloromethane/acetone (95/5), to give 0.43 g of 6-nitro-2,2-dimethyl-3-(trifluoroacetamido)methyl-3,4-dihydro-3,4-epoxy-2H-1-benzopyran 1NMR (CDCl3): δ 1.4 (s, 3H) , 1.6 (s, 3H), 3.7 (dd,1H), 3.85 (s, 1H), 4.15 (dd, 1H), 6.70 (br.s, 1H), 6.95 (d, 1H), 8.2 (d, 1H), 8.30 (s, 1H).

1. customthe organic phase separated
2. customevaporated under reduced pressure
3. customThe residue was chromatographed on silica gel
4. washeluting with dichloromethane/acetone (95/5)