反应详情

Aldehyde 12 (23 g) was suspended in 2% sodium hydroxide (300 mL) and a solution of 30% hydrogen peroxide (15.8 g, 1.4 eq.) was added. After 2 hours, another portion of 30% hydrogen peroxide (1.4 eq.) was added and the solution stirred overnight. The reaction mixture was acidified, extracted with dichloromethane, washed with sodium thiosulfate and the solvent removed in vacuo to afford a tan solid. The solid was recrystallized from methanol to afford colorless crystals (14 g, 64%): m.p. 122.3-124.3° C., lit20 m.p. 124-126° C.; EIMS m/z 220 (M+, 81Br), 218 (M+, 79Br), 205, 203, 177, 175, 95; 1HNMR δ 6.99 (1H, d, J=9.0 Hz, H5), 6.42 (1H, d, J=9.0 Hz, H4), 5.56 (1H, s, OH), 5.51 (1H, s, OH), 3.88 (3H, s, OCH3); 13C—NMR (75.5 MHZ) δ 146.59, 140.95, 133.47, 122.21, 104.35, 101.55, 56.31; Anal. Calcd. For C7H7O3Br: C, 38.39; H, 3.22. Found: C, 38.47; H, 3.36.

1. extractionextracted with dichloromethane
2. washwashed with sodium thiosulfate
3. customthe solvent removed in vacuo
4. customto afford a tan solid
5. customThe solid was recrystallized from methanol