A SYNTHESIS OF 2,3,4,6-TETRADEOXY-4-(DIMETHYLAMINO)-D-ERYTHRO-HEXOSE (FOROSAMINE) AND ITS D-THREO EPIMER

Oxidation of methyl 2,3,6-trideoxy-α-D-erythro-hexopyranoside (methyl α-amicetoside, 1) gave the 4-ketone 2, which was converted into the oxime 3 and (p-nitrophenyl)hydrazone. Hydrogenation of 3 in ethanolic hydrochloric acid over platinum gave a 2:3 mixture of methyl 4-amino-2,3,4,6-tetradeoxy-α-d-erythro-hexopyranoside hydrochloride and the D-threo isomer which, on N-dimethylation gave methyl 2,3,4,6-tetradeoxy-4-(dimethylamino)-α-D-erythro-hexopyranoside (8) and the D-threo isomer (11). Hydrolysis of 8 gave crystalline 2,3,4,6-tetradeoxy-4-(dimethylamino)-D-erythro-hexose (forosamine), and hydrolysis of 11 gave 2,3,4,6-tetradeoxy-4-(dimethylamino)-D-threo-hexose. Reduction of the ketone 2 with lithium aluminum hydride regenerated the starting alcohol 1 stereospecifically. Base-catalyzed deuterium-exchange converted ketone 2 into its 3,3-dideuterio derivative. Treatment of 2 with base, and subsequently with (p-nitrophenyl)hydrazine, in the presence of deuterium oxide, gave a 3,3,5-trideuterio (p-nitrophenyl)hydrazone derivative. © 1969.