Diastereoselective synthesis of C-glycosylnorbornenones

Article abstract of DOI:10.1016/0040-4020(95)00428-B

Thermal reaction of (E)-3,4,5,6,7-penta-O-acetyl-1,2-dideoxy-1-C-nitro-D-galacto- (1a) and D-manno-hept-1-enitol (1b) with 2-methyl-3,4-diaryl-5-phenylcyclopentadienones (2a-c) afforded diastereoselectively 1-methyl-2,3-diaryl-4-phenyl-(5S,6R)-5-exo-(D-galacto- (3a-c) and -(5R,6S)-5-exo-(D-manno-penta-O-acetylpentitol-1-yl)-6-endo-nitrobicyc lo[2.2.1]hept-2-en-7-ones (6a-c) and variable amounts of the 1-phenyl-4-methyl regioisomers 4a-c and 7a-c, depending upon the p-substituent in the aryl moiety. 1-C-arylalditols 5, 8-9 are also obtained in refluxing xylene.