Glucoside methyl 2-acetamido-2-deoxy

The synthesis of this substance, starting with methyl 2-acetamido-4,6-0-benzylidene-2-deoxy-a-D-glucoside, was performed as follows. The two isomers which were formed were separated on a Dowex 50 colunm, and one (Md +109°) was shown to be identical with natural muramic acid. The strong dextrorotation effectively ruled out the L-glucosamine configuration, and the configuration of the lactic moiety was deduced to be most likely d. The second isomer had [ ] +52° and differed, in its behavior on resin columns and in paper chromatography, from natural muramic acid. 

Graded hydrolysis with dilute acetic acid released methyl 2-acetamido-2-deoxy-3,4-di-0-methyl-a-n-glucoside, from which the known 3,4,6-trimethyl ether was prepared as evidence for the stability of the pyranose ring during the methylation procedure. The crystalline hydrochloride of the a anomer of the free sugar was obtained after hydrolysis with hydrochloric acid. Its free base was further characterized by crystalline JV-acetyl, iV-(benzyloxycarbonyl), and (2-hydroxy-1-naphthylmethylene) derivatives. 

The first preparation of a 4,6-dimethyl ether of 2-amino-2-deoxy-D-glucose was reported by Haworth, Lake, and Peat. Action of ammonia on methyl 2,3-anhydro-4,6-di-0-methyl-j3-D-mannoside, followed by N-acetylation of the product, led to the formation of methyl 3-acetamido-3-deoxy-4,6-di-0-methyl- S-D-altroside (in high yield) and of methyl 2-acetamido-2-deoxy-4,6-di-0-methyl- S-D-glucoside (in a 9.4% yield). Methylation of the latter compound yielded a 3,4,6-trimethyl ether identical with the one prepared from natural n-glucosamine. ... 

Walden inversion, at C3, of methyl 2-acetamido-2-deoxy-4-0-methyl-3,6-di-O-methylsulfonyl-a-D-glucoside took place on heating it with sodium acetate in 2-methoxyethanol (methyl Cellosolve) solution the product afforded, after acetylation, a sirupy methyl 2-acetamido-3,6-di-0-acetyl-2-deoxy-4-0-methyl-a-D-alloside. Removal of the 0-acetyl groups, followed by methylation, gave the same 3,4,6-trimethyl ether previously reported. 

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