Diethyl Ether → 2-(2,3-dihydro-4-oxo-6-methyl-5-phenyl-4H-1,3-oxazin-3-yl)-2-methyl-1-(2-methylenecyclopentyl)propan-1-one

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Reaction Steps

Powdered molecular sieve (4 A, 17 g) and pyridinium chlorochromate (4.3 g) were added to a stirred solution of 2-(2,3-dihydro-6-methyl-4-oxo-5-phenyl-4H-1,3-oxazin-3-yl)-2-methyl-1-(2-methylenecyclopentyl)propan-1-ol (3.1 g) in dichloromethane at 20° C. After 3 hours, ether was added and the mixture filtered, evaporated and the residue purified by silica gel column chromatography eluting with n-hexane/ethyl acetate (3:1) 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-one (Compound 1072, 1.55 g), NMR: 1.49(s,3H), 1.55(s,3H), 1.93(s,3H), 1.85-2.00(3H) 2.25-2.52(2H), 3.89(1H), 4.87(s,1H), 5.28(2H), 7.2-7.4(5H).

Provenance & Evidence