The Michael reaction of a methyl 2- C-nitro-α- d-hex-2-enopyranoside: Preparation and structural determination of the adducts having the d- altro-, d- gluco, and d- manno configurations

Abstract

The reactions of methyl 4,6- O-benzylidene-2,3-dideoxy-2- C-nitro-α- d- erythro-hex-2-enopyranoside ( 1) with 2,4-pentanedione and diethyl malonate afforded adducts having the d- altro, d- gluco, and d- manno configurations. Besides the adducts having the d- gluco and d- altro configurations, a 1,5-anhydro-2- C-nitrohex-1-enitol derivative was isolated in the reaction of 1 with dimethyl malonate. The product ratio was found to depend on the solvent. The nucleophilic addition and subsequent protonation appear to be respectively controlled kinetically and thermodynamically.