[EN] PROCESS FOR THE PREPARATION OF (1S,4R)-2-OXA-3-AZABICYCLO[2,2.1]HEPT-5-ENES<br/>[FR] PROCÉDÉ POUR LA PRÉPARATION DE (1S, 4R)-2-OXA-3-AZABICYCLO[2,2.1]HEPT-5-ÈNES
申请人:LONZA AG
公开号:WO2011023374A1
公开(公告)日:2011-03-03
Enantiomerically enriched (1 S,4R)-2-oxa-3-azabicyclo[2.2.1]hept-5-ene of formula wherein PG1 is an amino-protective group, are prepared from cyclopentadiene via hetero-Diels-Alder cycloaddition with protected 1-C-nitroso-β-D-ribofuranosyl halides of formula wherein X is a halogen atom selected from fluorine, chlorine, bromine and iodine, PG2 is a hydroxyl-protective group and PG3 is a 1,2-diol-protective group.