Mannoside methyl 4,6-0-benzylidene-3-deoxy-3

Methyl 6-deoxy-2,3-0-isopropylidene-4-0-tosyl-L-mannoside Methyl 0-deoxy-2,3-O-isopropyIidene-5-O-tosyl-L-mannoside Methyl 0-deoxy-2,3-di-O-methyl-4-O-to9yl- -L-mannoside Methyl 4,0-O-benzylidene-2-O-methyl-3-O-tosyl- 8-n-gaIactoside Methyl 0-deoxy-3-O-methyl-2,4-di-0-tosyl- 8-D-galactoside Methyl 0-deoxy-3,4-di-O-methyl-2-O-tosyl-acL-galactoside Methyl 2,0-dideoxy-3-O-methyl-4-O-tosyl-a-D- galactoside ... 

According to Irvine and Hynd, the deamination of methyl 2-deoxy-2-(dimethylamino)-D-glucopyranoside with a hot solution of barium hydroxide provides methyl n-glucoside. The effect of conformation on the nitrous acid deamination of amino hexoses is further illustrated by the reaction of methyl 3-amino-4,6-0-benzylidene-3-deoxy-a-D-altropyrano-side (LXVII) which, on deamination with nitrous acid, provides a quantitative yield of methyl 2,3-anhydro-4,6-0-benzylidene-a-D-mannoside (LXVIII). The deamination of methyl 3-amino-3-deoxy-)8-D-altropy-ranoside, methyl epiglucosamine, gives a sirupy mixture. Similar treatment of methyl 2-amino-4,6-0-benzylidene-2-deoxy-a-D-altroside... 

Neighboring group participation involving acylamino or acyloxy groups is common in nucleophilic substitution. For example, in the reaction of methyl 4,6-0-benzylidene-2-deoxy-2-benzoylamino-3-O-mesyl-a-D-altro-pyranoside 8 with NaOEt, no 3-0-ethoxy-mannoside derivative was obtained. Instead, oxazoline 9 and epimine 10 were identified in this reaction (O Scheme 5) [12]. This results from the l,2-tra 5 -diaxial relationship between the leaving... 

A similar methodology has utilized methyl 3-acetamido-4,6-0-benzylidene-3-deoxy-a-D-glucopyranoside (24), ° which upon inversion of configuration at C-2 produced the mannoside 25, whose benzylidene group was cleaved followed by acetylation to afford the... 

Amino-sugar Derivatives.—Methyl 4,6-0-benzylidene-2,3-dideoxy-2,3-phenyl-azo-a-D-mannoside, 2,4-bis(A-acetyl-A -benzoylamino)-3,6-di-0-benzoyl-2,4-dideoxy-a-D-idopyranoside, l-(JV-benzyl-iV-methyl)amino-l-deoxy-a-D-/yxo-hexulopyranose, 3,4,6-tri-0-acetyl-2-(N-acetyl)acetamido-l,2-dideoxy-D-ara6/no-hex-l-enopyranose, 7-acetamido-6,7,8-trideoxy-l,2 3,4-di-0-iso-propylidene-a-D- /ycew-D-j a/ac/o-octopyranose, and a-A, A -diacetylchito-biose. Further amino-derivatives are noted in the acid section below. 

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