Sodium hydride → (R)-3-((S)-1-(4-bromophenyl)ethyl)-6-(2-methylallyl)-6-phenyl-1,3-oxazinan-2-one

Participants

Reaction Conditions

Reaction Steps

The crude methyl (S)-1-(4-bromophenyl)ethyl(3-hydroxy-5-methyl-3-phenylhex-5-enyl)carbamate from above procedure was dissolved in dry THF (75 mL), NaH (60% in mineral oil, 274 mg, 2 equiv) was added slowly at rt. After 10 min, the mixture was heated to reflux for 2 h. LC-MS found reaction completed. The mixture was cooled to 0° C., quenched with satd aq NH4Cl (10 mL), diluted with ether (100 mL), washed with 1% aq HCl (25 mL) and brine (15 mL), and dried over Na2SO4. After filtration and concentration, the crude product was purified by chromatography on a 40-g silica gel column, eluted with 10-35% EtOAc in hexanes. The second UV active peak was collected to afford (R)-3-((S)-1-(4-bromophenyl)ethyl)-6-(2-methylallyl)-6-phenyl-1,3-oxazinan-2-one (490 mg 34.5% overall yield for Steps 3 and 4).

Provenance & Evidence