Hydrochloric Acid → 2-(2,3-dihydro-6-methyl-4-oxo-5-phenyl-4H-1,3-oxazin-3-yl)-2-methyl-1-(2-methylenecyclopentyl)propan-1-ol

Participants

Reaction Conditions

Reaction Steps

A solution of (cyclopent-1-enyl)methylbromide (3.8 g) in tetrahydrofuran was added to a stirred mixture of 2-(2,3-dihydro-6-methyl-4-oxo-5-phenyl-4H-1,3-oxazin-3-yl)-2-methylpropionaldehyde (3.5 g) and zinc powder(1.6 g) in tetrahydrofuran at 20° C. under an inert atmosphere. The temperature increased to 53° C. slowly and after 2 hours, ethyl acetate and hydrochloric acid (1N) were added and the organic phase washed with brine, dried (magnesium sulphate), evaporated and purified by silica gel column chromatography, eluting with n-hexane/ethyl acetate (2:1) to give 2-(2,3-dihydro-6-methyl-4-oxo-5-phenyl-4H-1,3-oxazin-3-yl)-2-methyl-1-(2-methylenecyclopentyl)propan-1-ol (3.66 g), NMR: 1.46(s,3H), 1.61(s,3H), 1.88(s,3H), 1.5-1.9(4H), 2.24(2H), 2.50(1H), 3.24(d,1H), 3.80(s,1H), 4.93(s,1H), 5.06(s,1H), 5.19(d,1H), 5.26(d,1H), 7.22-7.38(5H).

Provenance & Evidence