反应详情

This compound was prepared from 4,5,5-trimethylcyclohex-2-en-1-one (10) (169 mg, 1.22 mmol) in the manner previously described for benzylated enone 11, affording 0.337 g (59%) of the less polar trans diastereomer as a colorless, oily solid, along with 22 mg (4%) of the more polar cis diastereomer as a colorless, oily solid, separable by flash column chromatography. The relative stereochemistry of each respective diastereomer was confirmed by nOe NMR experiments. 1H NMR (400 MHz, CDCl3) δ 0.21 and 0.23 [2s, 2×3H, Si(CH3)2 ], 0.98 [s, 9H, SiC(CH3)3 ], 0.90 and 1.10 (2s, 2×3H, geminal-CH3 's), 1.11 (d, 3H, CHCH3), 2.45 (dd, 1H), 2.53 (ddd, 1H), 2.72 and 2.97 (d of ABq, 2H, benzylic-H's), 3.81 (s, 3H, OCH3), 5.87 (dd, 1H, 2-H), 6.55 (dd, 1H, 3-H), 6.64 (s, 1H, Ar--H), 6.93 ppm (s, 1H, Ar--H).

1. customaffording 0.337 g (59%) of the less polar trans diastereomer as a colorless, oily solid