Stereoselective intramolecular 1,3-dipolar cycloaddition of chiral chromium tricarbonyl complexed nitrone
作者:Clara Baldoli、Paola Del Buttero、Emanuela Licandro、Stefano Maiorana、Antonio Papagni、Alberto Albinati
DOI:10.1016/0957-4166(95)00217-d
日期:1995.7
The new tricarbonyl(2-allyloxybenzaldehyde)chromium(O) complex (4a) has been prepared in both a racemic and an enantiomerically pure form. The thermal intramolecular 1,3-dipolar cycloaddition of the corresponding (1R)-N-methyl nitrone (5a) afforded, after decomplexation, cis-(3aS,9bR)-1,3a,4,9b-tetrahydro-1-methyl-3H-[1] benzopyrano[4,3-c]isoxa zole (7) with complete enantioselection.