4-Toluenesulfonyl chloride → HCID 22118341, compound

Participants

Reaction Conditions

Reaction Steps

A solution of ethyl lithium (1.4M) in diethyl ether was added to a stirred solution of 2-(2,3-dihydro-6-methyl-4-oxo-5-phenyl-4H-1,3-oxazin-3-yl)-1-(3-hydroxymethyl-cyclopent-2-enyl)-2-methylpropan-1-ol (0.39 g) in tetrahydrofuran below -60° C. under an argon atmosphere. A solution of p-toluenesulphonyl chloride (0.23 g) in tetrahydrofuran was added below -65° C., followed after 0.5 hour by tetrakis(triphenylphosphine)palladium(0) (0.01 g) in tetrahydrofuran added below -60° C. Finally lithium triethylborohydride (1M) in tetrahydrofuran (1.4 ml) was added below -60° C. The mixture was allowed to slowly warm to 20° C. whilst stirring for 3 hours. Ethyl acetate and water were added and the organic phase washed (brine), dried (magnesium sulphate), evaporated and purified by column chromatography eluting with n-hexane/acetone (2:1) to give a mixture of 2-(2,3-dihydro-6-methyl-4-oxo-5-phenyl-4H-1,3-oxazin-3-yl)-2-methyl-1-(3-methylenecyclopentyl)propan-1-ol and 2-(2,3-dihydro-6-methyl-4-oxo-5-phenyl-4H-1,3-oxazin-3-yl)-2-methyl-1-(3-methylcyclopent-2-en-1-yl)propan-1-ol (0.1 g). To a stirred solution of the above mixture in dichloromethane were added powdered molecular sieve 4A (0.6 g) and pyridinium chlorochromate (0.15 g) at 20° C. After 3 hours, ether was added, the mixture filtered, evaporated and purified by silica gel column chromatography eluting with n-hexane/diethyl ether (2:1) to give 2-(2,3-dihydro-6-methyl-4-oxo-5-phenyl-4H-1,3-oxazin-3-yl)-2-methyl-1-(3-methylenecyclopentyl)propan-1-one (Compound 1076, 25 mg), NMR: 1.44(s,6H), 1.94(s,3H), 1.85-2.60(6H), 3.32(1H), 4.84(s,1H), 5.27(s,2H), 7.22-7.40(5H).

Provenance & Evidence