Water → 1-(cyclohex-2-enyl)-2-(2,3-dihydro-6-methyl-4-oxo-5-phenyl-4H-1,3-oxazin-3-yl)-2-methylpropan-1-ol

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Reaction Conditions

Reaction Steps

A solution of 1-bromocyclohex-2-ene (7.2 g) in tetrahydrofuran was added dropwise during 0.5 hour to a stirred mixture of 2-(2,3-dihydro-6-methyl-4-oxo-5-phenyl-4H-1,3-oxazin-3-yl)-2-methylpropionaldehyde (4.0 g) and zinc powder (3.2 g) in tetrahydrofuran below -20° C. under an inert atmosphere. The mixture was stirred for 1 hour below -20° C. and warmed to 20° C. Ethyl acetate and water were added and the organic phase washed (brine), dried (magnesium sulphate), evaporated and purified by silica gel column chromatography, eluting with n-hexane/ethyl acetate (5:2) to give 1-(cyclohex-2-enyl)-2-(2,3-dihydro-6-methyl-4-oxo-5-phenyl-4H-1,3-oxazin-3-yl)-2-methylpropan-1-ol (5.1 g), NMR: 1.41(s,3H), 1.53(s,3H), 1.85(s,3H), 1.40-2.05(6H), 2.24(1H), 3.49(1H), 4.32(d,1H), 5.1 1(d 5.24(d,1H), 5.60(1H), 5.76(1H), 7.20-7.40(5H).

Provenance & Evidence