The Methyl Ethers of D-Glucosamine

The synthesis of the 3-methyl ether of 2-amino-2-deoxy-D-glucose was accomplished in 1941 by Neuberger. The hydroxyl groups at C4 and C6 

In the course of the synthesis of 2-amino-2-deoxy-3,4-di-0-methyl-D-glucose, the 3-methyl ether of methyl 2-acetamido-2-deoxy-6-0-trityl-a-D-glucopyranoside was obtained as a secondary product on methylation with Purdie s reagents. Elimination of the trityl group afforded the same glycoside as that obtained by Neuberger. 

Proof of the location of the methoxyl group at C3 was established by application of periodate oxidation to methyl 2-acetamido-2-deoxy-3-0-methyl-a-D-glucopyranoside and to 2-amino-2-deoxy-3-0-methyl-D-gluconic acid. The first compound was resistant to oxidation, whereas the second consumed two equivalents of periodate per mole and released one mole of formaldehyde and one mole of formic acid per mole, but afforded no ammonia.  

The 3-methyl ethers of the 4,6-0-benzylidene and 4,6-0-ethylidene derivatives of methyl 2-(A-benzyloxycarbonyl)amino-2-deoxy-a-n-gluco-pyranoside have been prepared by a sequence of reactions paralleling Neuberger s synthesis. The d anomer of the latter compound was obtained directly by methylation of 2-(A-benzyloxycarbonyl)amino-2-deoxy-4,6-0-ethylidene-D-glucose with dimethyl sulfate and alkali. Both anomers were transformed into the free amines by catalytic hydrogenolysis.  

A 4-methyl ether of a 2-amino-2-deoxy-D-glucose derivative was first obtained as a by-product in the methylation of methyl 2-acetamido-2-deoxy-6-O-trityl-a-n-glucopyranoside with Purdie s reagents.  

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