Cellobiose benzoylation

A remarkable inertness towards acylation is shown by the secondary hydroxyl group on C-3 in maltose, lactose, and their methyl j8-glycosides. Benzoylation of maltose with 10 molar equivalents of the acid chloride in pyridine gave122 the octabenzoate and the l,2,6,2, 3, 4, 6 -hepta-0-benzoyl derivative in the ratio of 5 6, and treatment of /3-maltose monohydrate with 8.8 molar equivalents of acetyl chloride in pyridine-toluene at 0° gave123 the 1,2,6,2, 3, 4, 6 -heptaacetate and the octaacetate in the ratio of 27 10. Under similar conditions of benzoylation, cellobiose was converted into its oc-... 

R. S. Bhatt, L. Hough, and A. C. Richardson, The chemistry of cellobiose and lactose. Part 7. Selective benzoylation of methyl P-lactoside, J. Chem. Soc. Perkin Trans. 1, 1 (1977) 2001-2005. 

Importantly, this halogenation process can be extended to members of the disaccharide series, and the lactose, maltose, and cellobiose derivatives 61, 62, and 63 afford the crystalline a-glycosyl bromides 64,65, and 66 in almost quantitative yields (see Scheme 10).51 As these O-benzoylated oximes are... 

Linear Homotrisaccharides. - Maltose, cellobiose and lactose as 0-pro-tected p-thioglycosides have been tethered via their 0-2 to 0-3 of benzyl 6-0-benzyl-2-O-benzoyl-a-D-glucopyranoside. Cyclization induced by NIS gave a-linked trisaccharide products in about 60% yield. This approach has therefore given access to a-D-Glc-(l- 4)-a-D-Glc-(l- 4)-D-Glc, p-D-Glc-(l- 4)-a-D-Glc-(1—4)-d-G1c and p-D-Gal-(l- 4)-a-D-Glc-(l- 4)-D-Glc.3 ... 

The preparation of the octa-Q-benzoyl-aldobiononitriles of cellobiose, gentiobiose, lactose, and maltose from the unprotected oximes has been effected by treatment with benzoyl chloride in pyridine at SO C. Reaction of melibiononitrile perbenzoate with methanolic ammonia yielded the 1,1-dibenzamido-derivative (37) as the major product, isolated in 38% yield.The erythro- and threo-cyanohvdrins (38) were obtained in a 4 1 ratio from 2,3-Q-isopropylidene-D-glyceraldehyde on reaction with trimethylsilyl cyanide, and were converted to the four carbon lactone synthons (39). The chiral hexane-1,6-dinitrile (40) has been synthesized CHjOH... 

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