Dideoxy methylation

Methyl 6,8-dideoxy-6-(l-methyl-trans-4-propyl-L-pyrrolidin-2-ylcarbonylamino)-l-thio-D-erythro-D-galacto-octopyranoside... 

Branched-chain sugars are found in nature, eg, cladinose, ie, 2,6-dideoxy-3-C-meth5l-3-0-methyl-L- 7 (9hexose [3758-45-0] a component of erythromycin. 

Product 15 was eventually transformed into methyl 4,6-dideoxy-a-D-xylo-hexopyranoside by reductive desulfurization. A related reaction is the formation (41) of the 4-thiocyanato derivative 17 in 47% yield from 16 (140°C., 22 hours in N,N-dimethylformamide). This has been suggested as a good route to 4-deoxy-D-xt/Zo-hexoses compared with the available methods (43). 

An attractive feature in this reaction is the possibility of direct substitution and formation of unblocked sugar derivatives containing one or more chlorodeoxy function in essentially two steps. Another facet is the formation of methyl 4,6-dichloro-4,6-dideoxy-hexosides from certain methyl glycosides in one step. Such compounds could be valuable intermediates in the synthesis of dideoxy and diamino sugars of biological importance. 

Treatment of l,4 3,6-dianhydro-D-glucitol with boron trichloride gives l,6-dichloro-l,6-dideoxy-D-glucitol (20). Although methyl 6-chloro-6-deoxy-a-D-glucopyranoside (isolated as the tribenzoate) could be isolated from the reaction of methyl 3,6-anhydro-a-D-glucopyranoside with boron trichloride (21), the application to the isomeric furanoside derivative led to complex results. 

Dehydroquinic acid and [l,6-14C]-D-shikimic acid methyl ester were not incorporated, indicating a very early branch from the shikimate pathway. The intermediacy of 4-amino-3,4-dideoxy-D-araf>ino-heptulosonic acid 7-phosphate (37) was proposed, consistent with later findings on the role of the variant aminoshikimate pathway [94]. 

Methyl (3/ )-3-Amino-4,6-0-1 ///.S)-henzylidcne-3-C-cyano-2,3-dideoxy-2,2-C-dimcthyEa-u-fi 6o-hexopyran-oside28 ... 

Synthesis of Chromose A (2,6-Dideoxy-4 G-methyl-n-galactose), J. S. Brimacombe, D. Portsmouth, and M. Stacey, Chem. Ind. (London), (1964) 1758. 

Nucleophilic Displacement Reactions in Carbohydrates. Part XI. Reaction of Methyl 6-Deoxy-2,3-O-isopropylidene-4-O-methyl-sulphonyl-a-L-talopyranoside with Sodium Azide A Synthesis of L-Perosamine (4-Amino-4,6-dideoxy-L-mannose) Derivatives, J. S. Brimacombe, O. A. Ching, and M. Stacey, J. Chem. Soc. C, (1969) 1270-1274. 

Methyl 5-acetamido-3,5-dideoxy-D-g/ycero-p-D-ga/acfo-non-2-ulopyranosonate... 

Methyl 3,4-dideoxy-p-D-g/ycero-hept-3-en-2-ulopyranosid-5-ulose... 

Dideoxy-3-[3-hydroxy-2-(hydroxymethyl)propyl]-4-C-methyl-L-mannose (not the alternative /Ztrco-hexose)... 

The carbon atoms of the parent chain are numbered according to 2-Carb-2.2.1. If a unique numbering is required for the branch(es) (e.g. for X-ray orNMR work), the carbon atoms may be given the locant of the appropriate branch point, with the internal branch locant as superscript, e.g. 42 for position 2 of the branch at position 4 of the main chain. This style of branch numbering is not to be used for naming purposes e.g. the side-chain-methylated derivative of compound 5 is named 4,6-dideoxy-3-C-[(I )-1 -methoxyethyl]-D-n7w-hexose, and not as a s -O-methyl derivative. 

Methyl (ethyl 2,4-dideoxy-p-D-glucopyranoside-2,4-diyl)phosphinite or ethyl 2,4-dideoxy-2,4-(methoxyphosphanediyl)-p-D-glucopyranoside... 

Note. The alternative fusion name (see 2-Carb-35.2) is hexahydro(methyl 2,3-dideoxy-P-D-glucopyranosido)[2,3]benzene... 

Methyl 2,3-(buta-1,3-diene-1,4-diyl)-2,3-dideoxy-p-D-eryfhro-hex-2-enopyranoside... 

Methyl 4-/V-acetyl-2,3-di-0-acetyl-4,6-diamino-4,6-A/-cyclo-4,6-dideoxy-a-D-... 

Cladinose 2,6-Dideoxy-3-C-methyl-3-Omethyl- L-ribo-hexose... 

Oleandrose Panose 2,6-Dideoxy-3-0-methyl-L-arab/no-hexose a-D-Glucopyranosyl-(1 ->6)-a-D-glucopyranosyl-(1- 4)-D-glucose... 

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