Mannopyranoside methyl 2,3-anhydro-4,6-0-benzylideneD

The first synthesis of D-glucosamine which proved its configuration was carried out in the following way NH3 was added to methyl-2,3-anhydro-4,6-benzylidene-a-D-mannopyranoside. After removal of the protective methyl and benzylidene groups a good deal of 3-amino-3-deoxyaltrose and a little 2-amino-2-deoxyglucose were obtained. Instead of the benzyl-... 

Ci4HlfiOs Methyl 2,3-anhydro-4,6-0-benzylidene-a-D-mannopyranoside MABMPY 30 454... 

The deamination of methyl 3-amino-3-deoxy-/3-D-altropyranoside was studied in 1934, but the products were not fully characterized.14411 The syrupy product was converted into a methylated derivative that had an elemental analysis corresponding to that calculated for a methyl tetramethylhexoside. The conditions used for methyl-ation would have opened an epoxide ring. Methyl 2,3-anhydro-4,6-0-benzylidene-a-D-mannopyranoside precipitated quantitatively from solution when the corresponding 3-amino-3-deoxyaltroside derivative was deaminated in aqueous medium.145 Epoxide formation was likewise reported to be quantitative in the deamination of the analogous 2-amino-2-deoxyaltroside.83 145 On deamination, 4-amino-l,6-anhydro-4-deoxy-/3-D-mannopyranose also gave an epoxide, namely, 1,6 2,3-dianhydro-/3-D-talopyranose, in unspecified yield.146... 

V. S. Murthy, A. S. Gaitonde, and S. P. Rao, One-pot conversion of 1,2-diols to epoxides —convenient preparation of methyl 2,3-anhydro-5-0-trityl-/ -D-lyxofuranoside and methyl 2,3-anhydro-4,6-0-benzylidene-a-D-mannopyranoside, Synth. Common., 23 (1993) 285-289. 

Reactions leading to the formation of alkenic or a,/3-unsaturated bonds are very important in synthesis. This type of functionality is synthetically versatile, and of wide utility in the carbohydrate field. The use of sulfur reagents for conversion of sugar epoxides on vicinal disulfonates into al-kenes is well established97a 97b, and subsequent work with selenium reagents provided essentially comparable results. Thus, treatment of methyl 2,3-anhydro-4,6-0-benzylidene-a-D-mannopyranoside (219) with potassium selenocyanate in aqueous 2-methoxymethanol afforded methyl 4,6-0-benzylidene-2,3-dideoxy-a-D-ery/firo-hex-2-enopyranoside (220).27 Similarly, treatment of 5,6-anhydro-l,2-0-isopropylidene-a-D-glucofuranose (221) with potassium selenocyanate in methanol at room temperature... 

Triphenyltin lithium has been used to open the oxiran rings of methyl 2,3-anhydro-4,6-0-benzylidene-a-D-allo- and -mannopyranosides to give the tin-bonded altrosides (10) and (11) in 75 and 94% yield respectively. A 43% yield of the C-6 bonded tin derivative (12) was obtained by using the reagent to displace the corresponding tosylate. The n.m.r. of these products is reported in Chapter 20." ... 

Benzyl 2,3-anhydro-4-0-a-L-arabinopyranosyl-p-D-ribopyranoside, A-848 Benzyl 2,3-anhydro-4,6-0-benzylidene-a-D-allopyranoside, A-484 Benzyl 2,3-anhydro-4,6-0-benzylidene-p-D-gulopyranoside, A-639 Benzyl 2,3-anhydro-4,6-0-benzylidene-a-D-mannopyranoside, A-676 Benzyl 3,4-anhydro-2,6-dideoxy-a-L-r -hexopyranoside, A-591 Benzyl 2,3-anhydro-4- O - p-D-galactopyranosyl- p-D-ribopyranoside, G-173 Benzyl 2,3-anhydro-a-D-mannopyranoside, A-676 Benzyl 2,3-anhydro-p-D-mannopyranoside, A-676 Benzyl 3,4-anhydro-2-0-mesyl-6-0-trityl-a-D-altropyranoside, A-495 Benzyl 2,3-anhydro-4-0-methyl-p-D-ribopyranoside, A-693 Benzyl 2,3-anhydro-p-D-ery /iro-pentopyranosid-4-ulose, A-682 Benzyl 2,3-anhydro-p-L-eyy /iro-pentopyranosid-4-ulose, A-682 Benzyl 2,3-anhydro-a-D-ribopyranoside, A-693 Benzyl 2,3-anhydro-p-D-ribopyranoside, A-693 Benzyl 2,3-anhydro-p-L-ribopyranoside, A-693... 

Methyl 2-0-acetyl-3,4-anhydro-a-D-arabinopyranoside, A-504 Methyl 2-0-acetyl-3,4-anhydro-p-L-arabinopyranoside, A-504 Methyl 4-0-acetyl-2,3-anhydro-6-deoxy-a-D-gulopyranoside, A-527 Methyl 4-0-acetyl-2,3-anhydro-6-deoxy-p-D-gulopyranoside, A-527 Methyl 4-0-acetyl-2,3-anhydro-6-deoxy-a-D-mannopyranoside, A-687 Methyl 4-0-acetyl-3,6-anhydro-a-D-galactopyranoside, A-620 Methyl 5-0-acetyl-2,3-anhydro-a-D-lyxofuranoside, A-664 Methyl 5-0-acetyl-2,3-anhydro-p-D-lyxofuranoside, A-664 Methyl 3-0-acetyl-2,6-anhydro-4-0-methyl-p-D-mannopyranoside, A-678 Methyl 4-0-acetyl-2,3-anhydro-a-D-rhamnopyranoside, A-687 Methyl 5-0-acetyl-2,3-anhydro-a-D-ribofuranoside, A-690 Methyl 5-0-acetyl-2,3-anhydro-p-D-ribofuranoside, A-690 Methyl 4-0-acetyl-2,3-anhydro-p-D-ribopyranoside, A-693 Methyl 4-0-acetyl-2,3-anhydro-6-0-trityl-a-D-mannopyranoside, A-676 Methyl 2-0-acetyl-p-L-arabinopyranoside, M-153 Methyl 3-0 -acetyl-2-azido-4,6-0 -benzylidene-2-deoxy-a-D-mannopyranoside, A-912... 

Methyl 3-0-acetyl-2,6-anhydro-4-0-methyl-p-D-mannopyranoside, A-678 Methyl 4-0-acetyl-2,3-anhydro-6-0-trityl-a-D-mannopyranoside, A-676 Methyl 3-0-acetyl-4,6-0-benzylidene-2-bromo-2-deoxy-a-i> mannopyranoside, B-87... 

Methyl 6-0-acetyl-2,3-di-O-benzyl-a-D-mannopyranoside, M-204 Methyl 4-0-acetyl-2,3-di-0-methyl-a-D-mannopyranoside, D-748 Methyl 4-0-acetyl-2,3-0-isopropylidene-6-0-methyl-a-D-mannopyranoside, M-200 Methyl 4-O-acetyl-a-D-mannopyranoside, M-204 Methyl 6-O-acetyl-p-D-mannopyranoside, M-205 Methyl 4-0-acetyl-6-0-methyl-a-D-mannopyranoside, M-274 Methyl 2-0-acetyl-3,4,6-tri-0-benzyl-a-D-mannopyranoside, M-204 Methyl 4-0-acetyl-2,3,6-tri-0-methyl-a-D-mannopyranoside, T-190 Methyl 3-amino-3-deoxy-p-D-mannopyranoside, A-313 Methyl 3-amino-3-deoxy-a-D-mannopyranoside, A-313 Methyl 2,3-anhydro-4,6-0-benzylidene-(3-D-mannopyranoside, M-169 Methyl 2,3-anhydro-4,6-0-benzylidene-a-D-mannopyranoside, A-676 Methyl 2,3-anhydro-4-0-benzyl-6-0-trityl-a-D-mannopyranoside, A-676 Methyl 2,3-anhydro-4,6-di-0-methyl-p-D-mannopyranoside, A-676 Methyl 2,3-anhydro-4,6-di-0-tosyl-a-D-mannopyranoside, A-676 Methyl 2,3-anhydro-4,6-0-ethylidene- -D-mannopyranoside, A-676 Methyl 2,6-anhydro-a-D-mannofuranoside, A-671 Methyl 3,6-anhydro-a-D-mannofuranoside, A-679 Methyl 2,3-anhydro-a-D-mannopyranoside, 8CI, A-676 Methyl 2,3-anhydro-p-D-mannopyranoside, A-676 Methyl 2,6-anhydro-a-D-mannopyranoside, A-678 Methyl 3,6-anhydro-a-D-mannopyranoside, A-679 Methyl 3,6-anhydro-p-D-mannopyranoside, A-679 Methyl 2,3-anhydro-6-0-trityl-a-D-mannopyranoside, A-676 Methyl 6-azido-6-deoxy-2,3-0 -isopropylidene-a-D-mannofuranoside, A-913... 

Methyl 2,3-diacetainido-2,3-dideoxy-a-D-mannopyranoside, D-449 Methyl 2,3-diacetamido-2,3-dideoxy-p-D-mannopyranoside, D-449 Methyl 3,6-diacetamido-3,6-dideoxy-a-D-mannopyranoside, D-451 Methyl 3,4-di-0-acetyl-2,6-anhydro-a-D-niannopyranoside, A-67S Methyl 3,4-di-0-acetyl-2,6-anhydro-p-i>mannopyranoside, A-67S Methyl 2,3-di-0-acetyl-4,6-0-benzylidene-a-D-mannopyranoside, M-169 Methyl 2,4-di-0-acetyl-3,6-di-0-benzoyl-a-D-mannopyranoside, M-204 Methyl 4,6-di-0-acetyl-2,3-di-0-benzyl-a-D-mannopyranoside, M-204 Methyl 2,3-di-0-acetyl-4,6-0-ethylidene-a-D-mannopyranoside, M-I80 Methyl 5,6-di-0-acetyl-2,3-0-isopropylidene-a-D-mannofuranoside, 1-71 Methyl 4,6-di-O-acetyl-a-D-mannopyranoside, M-204 Methyl 2,3-di-0-acetyl-4,6-0-methylene-a-D-mannopyranoside, M-204 Methyl 2,3-diamino-2,3-dideoxy-p-D-mannopyranoside, D-449 Methyl 3,6-diamino-3,6-dideoxy-a-D-mannopyranoside, D-451 Methyl 3,6-di-0-benzoyl-2,4-di-0-methyl-a-D-mannopyranoside, D-749 Methyl 3,6-di-O-benzoyl-a-D-mannopyranoside, M-204 Methyl 2,6-di-0-benzoyl-3-0-methyl-p-D-mannopyranoside, M-205 Methyl 2,3-di-0-benzyl-4,6-0-benzylidene-a-D-mannopyranoside, M-169 Methyl 2,3 4,6-di-0-benzylidenemannopyranoside 0L-i>-( R, R)-form, M-172... 

The 2,3-> 3>5- and 5 6-benzylidene acetals of 1,4-anhydro-D-mannitol with the ( R)- and ( )-acetal configurations have all been obtained. Interconversion of the exo- and endo-2.3-0-benzylidene acetal in methyl 2,3 4>>6-di- -benzylidene— (-D-mannopyranoside using catalytic aluminium(III) chloride has been described. The exo-... 

The reaction of gaseous [ F] fluorine or [ F] acetyl hypofluorite with tri-Q-acetyl-D-galactal has allowed the synthesis of 2-deoxy-2[ Flfluoro-D-galactose. Nucleophilic displacements employing [ F] fluoride ions on either methyl 3-Q-benzyl-4,6-0-benzylidene-2-Q-triflyl-p-D-mannopyranoside or 1,6-anhydro-3,4-di-Q-benzyl-2-Q-triflyl-p-D-mannopyranose have given access to 2-deoxy-2-[ F]fluoro-D-glucose. 

Syntheses of naturally occurring (-f)-blastmycinone (280) and its C-3 and C-4 stereoisomers have been reported. The C-butyl branch was introduced by reaction of methyl 2,3-anhydro-4,6-0-benzylidene-a-D-mannopyranoside with n-butyl magnesium chloride to give methyl 4,6-6>-benzylidene-3-C-butyl-3-deoxy-a-D-altropyranoside, which was degraded and transformed into the i. arabino isomer (280) (see Vol. 9, p. 204). 

The reaction of methyl 2,3-anhydro-4,6-0-benzylidene-o-D-mannopyranoside with Ph2AsLi gave rise to the corresponding 3-deoxy-3-C-diphenylarsino-altropyranoside, whereas methyl 2,3-anhydro-4,6-D-benzylidene-a-D-allopyra-noside with Ph2AsLi or PhsSnLi gave the corresponding 2-deoxy-2-C-diphenyl-... 

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