2-Bromohexanoic acid → Diphenylmethyl alpha-bromohexanoate

関与物質

反応手順

α-Bromohexanoic acid (1.95 g) in light petroleum spirit (25 ml, b.p. 40°-60°) was treated with a stock solution of diphenyldiazomethane in petroleum spirit (b.p. 40°-60°) (ca. 3.8 mmole/10ml) dropwise with stirring until a faint violet colour persisted. The mixture was stirred for 2 hours at room temperature, whereupon the solvent was removed in vacuo. The resulting oil in ethyl acetate was washed with a saturated aqueous solution of sodium bicarbonate then with water and dried. Removal of the solvent gave the title ester (3.0 g, 90%), λmax (EtOH) 252, 258, 263.5, 267.5 and 276 nm (ε 1650, 1600, 1350, 1150 and 850).

情報源と証拠