A Study on the Kinetically Controlled Cyclization of 6-Deoxy-3-O-methyl-6-nitro-D-glucose and-L-idose, and the Preparation of Optically Active Nitroinositol Derivatives

The cyclization (internal Henry addition) of 6-deoxy-3-O-methyl-6-nitro-D-glucose (1) and-L-idose (2) was investigated with respect to the sequence in which stereoisomeric deoxynitroinositol methyl ethers are formed from each. It was found that, under conditions of kinetic control, the primary products generated from 1 are the nitronate 4′ (that corresponds to the epimeric deoxynitroinositols 4 and 5 having the epi-3 and muco-3 configurations, respectively) and the nitronate D-6′ of optically active 1-deoxy-4-O-methyl-1-nitro-L-myo-inositol (L-6). They are formed in approximately equal proportions. Ensuing thermodynamically controlled processes lead to racemization of L-6 and formation of the scyllo isomer 3 at a relatively slow rate. The cyclization of 2, found to be faster than that of 1, gave as primary products the enantiomeric nitronate D-6′ and the nitronate 3′ in a ratio of about 4:1. The nitronate 4′ arose by subsequent epimerization. The optically active compounds D-6 and L-6 were isolated in pure, crystalline form.