Bromide ion → HCID 22118336, compound

Participants

Reaction Conditions

Reaction Steps

A part of a solution of 1-bromocyclopent-1-ene (3.9 g) in tetrahydrofuran was added to a stirred mixture of magnesium turnings (0.68 g) and 1 drop of 1,2-dibromoethane in tetrahydrofuran at 20° C. under an inert atmosphere. The mixture was heated to reflux and the remaining bromide solution added dropwise over 15 minutes. The mixture was stirred for 0.5 hour, cooled to 0° C., and a solution of 2-(2,3-dihydro-6-methyl-4-oxo-5-phenyl-4H-1,3-oxazin-3-yl)-2-methylpropionaldehyde (4.0 g) in tetrahydrofuran added below 10° C. The mixture was stirred for 1 hour and ethyl acetate and hydrochloric acid (1N) added. The organic phase was washed (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-(cyclopent-1-enyl)propan-1-ol (4.95 g), NMR: 1.45(s,3H), 1.60(s,3H), 1.90(s,3H), 1.80-1.92(2H), 2.15-2.53(4H), 4.37(d,1H), 5.04(d,1H), 5.20-5.30(2H), 5.63(s,1H), 7.22-7.41(5H).

Provenance & Evidence