tert-butyl (4aS,7aR)-3,4,4a,5,7,7a-hexahydro-2H-pyrrolo[3,4-b][1,4]oxazine-6-carboxylate

Conditions: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: A mixture of 417 mg of cis-8-tert-butoxycarbonyl-5-[(1R)-1-phenylethylamino]-2-oxa-5,8-diazabicyclo[4.3.0]nonane 14a and 200 mg of 10% palladium on charcoal in 50 ml of ethanol was shaken under a pressured hydrogen atmosphere of 4.5 kg/cm2 for 4 hours. Then further 100 mg of 10% palladium on charcoal was added and hydrogenation was carried out under the above-mentioned condition. Throughout the reaction, the reaction vessel was heated by irradiation with a tungsten lamp. The catalyst was removed by filtration, and the solvent of the filtrate was removed under reduced pressure. The residue was subjected to silica gel column chromatography. From an eluant of chloroform containing 10% methanol, the titled compound 15a weighing 286 mg was obtained. Throughout the reaction the reaction vessel was heated by irradiation with a tungsten lamp The catalyst was removed by filtration the solvent of the filtrate was removed under reduced pressure was obtained