The Methyl Ethers of 2-Amino-2,6-dideoxy-D-galactopyranose (D-Fucosamine)

The 3-, 4-, and 3,4-dimethyl ethers of 2-amino-2,6-dideoxy-D-galactose (D-fucosamine) have been synthesized. 2-Amino-2,6-dideoxy-3,4-di-O-methyl-D-galactose was made by the methylation of methyl 2-acetamido-2,6-dideoxy-α-D-galactopyranoside to its 3,4-di-O-methyl derivative which was hydrolyzed to yield pure 2-amino-2,6-dideoxy-3,4-di-O-methyl-D-galactose hydrochloride. 2-Amino-2,6-dideoxy-3-O-methyl-D-galactose was made from methyl 2-acetamido-2-deoxy-3-O-methyl-α-D-galactopyranoside by conversion of its 6-sulfonate to the 6-deoxy-6-iodo derivative, followed by reduction to the 6-deoxy derivative which, on hydrolysis, gave 2-amino-2,6-dideoxy-3-O-methyl-D-galactose hydrochloride. 2-Amino-2,6-dideoxy-4-O-methyl-D-galactose was made from methyl 2-acetamido-2-deoxy-3,6-di-O-(p-tolylsulfonyl)-α-D-galactopyranoside which was methylated to yield the 4-O-methyl derivative and subsequent conversion of the latter compound to its 6-deoxy derivative, via its 6-deoxy-6-iodo derivative, followed by detosylation, gave methyl 2-acetamido-2,6-dideoxy-4-O-methyl-α-D-galactopy-ranoside convertible by acid hydrolysis to 2-amino-2,6-dideoxy-4-O-methyl-D-galactose hydrochloride.