Carbamate → tert-Butyl [2-(3-acetyl-5-chloro-2-methoxy-6-methylphenyl)-2-hydroxyethyl]carbamate

Participants

Reaction Steps

0.2 M Osmium tetraoxide in water (1 mL) was added to a solution of tert-butyl [(4-chlorobenzoyl)oxy]carbamate (2.0 g, 7.2 mmol) (Ref Lawrence Harris, J. Org. Chem., 2011, 76, 358-372) in acetonitrile (22 mL) and stirred for 10 minutes. 1-(5-Chloro-2-methoxy-4-methyl-3-vinylphenyl)ethanone (1.1 g, 4.8 mmol) as a solution in acetonitrile (22 mL) was added to the carbamate solution followed by the addition of water (5 mL). The reaction was stirred for 3 hours at room temperature. The reaction was quenched with saturated 10 M dipotassium disulfite in water (25 mL) and stirred for 5 minutes. Water was added to the reaction and the mixture was extracted with ethyl acetate. The organic extracts were washed with saturated sodium bicarbonate solution, brine, dried over sodium sulfate and evaporated under reduced pressure. Purification on silica gel using ethyl acetate in hexane (0-100%) gave the desired compound as a racemic mixture, 1.2 g, 69%. LCMS calculated for C17H24ClNO5Na (M+Na)+: m/z=380.1; found: 380.1. 1H NMR (500 MHz, DMSO-d6): δ 7.48 (s, 1 H), 6.80 (m, 1 H), 5.50 (br s, 1 H), 5.20 (br s, 1 H), 3.83 (s, 3 H), 3.32 (m, 1 H), 3.22 (m, 1 H), 2.59 (s, 3 H), 2.55 (s, 3 H), 1.32 (s, 9 H).

Provenance & Evidence