NUCLEOPHILIC RING-OPENING IN A CARBOHYDRATE NITROCYCLOPROPANE: A STEREOSPECIFIC APPROACH TO CHIRAL ISOALKYL STRUCTURES

Article abstract of DOI:10.1016/0008-6215(88)85098-5

Chemical reactions to open the cyclopropane ring in (1R)-1,2-dideoxy-3,4:5,6-di-O-isopropylidene-1,2-C-methylene-1-nitro-D-mannitol (1) were investigated.Catalytic hydrogenation over Pd-C produced the corresponding 1-amino compound, isolated as its N-acetyl derivative, but failed to cleave the ring.However, ring opening succeeded by nucleophilic addition of sodium thiophenoxide to 1, giving 1,2-dideoxy-3,4:5,6-di-O-isopropylidene-1-nitro-2-C-(phenylthio)methyl-D-mannitol.The latter reacted further with thiophenoxide to furnish phenyl 2-deoxy-3,4:5,6-di-O-isopropylidene-2-C-(phenylthio)methyl-D-mannothiohydroximate.Raney nickel converted both of these thio sugar derivatives into the same product, namely, 1-acetamido-1,2-dideoxy-3,4:5,6-di-O-isopropylidene-2-C-methyl-D-mannitol.The use of these transformations for the design of stereospecific syntheses of chiral isoalkyl structures is proposed.