6-deoxy Sucrose

Sucrose Ethers. Being next to the anomeric center and intramolecularly hydrogen-bonded, the 2 -OH of sucrose is the most acidic, which means it is deprotonated first under alkaline conditions, and thus preferentially yields to etherification. Benzylation with NaH/benzylbromide in DMF, for example, results in an 11 2 1 mixture of 2 -(9-benzyl-sucrose (Figure 2.8) and its 1-0- and 3 -0-isomers. Because the former is readily accessible, it proved to be a versatile intermediate for the generation of 2 -modified sucroses, for example, the 2 -keto and 2 -deoxy derivatives as well as sucrosamine (2 -amino-2 -deoxy-sucrose), whose application profiles remain to be investigated. 

Stoichiometric quantities of uridine diphosphate glucose were used, in the presence of a transfer enzyme, sucrose synthetase, in the soluble state (extraction given). Coupling with modified D-fructose gave sucroses modified on the D-fructosyl group, on the 1 -3-mmol scale. Thus were prepared l -deoxy-l -fluoro- (59%),98 4 -deoxy-4 -fluoro- (16%), and l -azido-l -deoxy-sucrose (15%).71 6-Deoxy-6-fluoro-D-glucose was isomerized to 6-deoxy-6-fluoro-D-fructose with isomerase, and gave 6 -deoxy-6 -fluoro-sucrose.71... 

An Improved six-step synthesis of 6-deoxy-sucrose from sucrose, ... 

Amino-3-deoxy-sucrose has been synthesized from sucrose by sequential oxidation at C-3 by Agrobacterium tumefaciens (40% yield), peracetylation, reduction of the C-3 ketone to an a//o-configured product (H2, Pt), trifluoro-methanesulfonylation, displacement by azide with inversion, deacetylation and hydrogenation. 4-Amino-4-deoxy-sucrose was obtained from a sucrose hepta-pivaloate by double inversion at C-4 by sequential triflate displacement reactions, first with nitrite then azide ion. Various 4-alkylamino-2,4-dideoxy-L-r/ireo-pentopyranosides 15, components of the calicheamicins, were synthesized from... 

Trichloro-4,6,6 -trideoxygalactosucrose or6-chloro-6-deoxy-p-D-fructofuranosyl 4,6-dichloro-4,6-dideoxy-a-D-galactopyranoside ( galactosucrose is a trivial name for the 4-epimer of sucrose)... 

Deoxy-4-fluoro- a/flc/o-sucrose (617 4-deoxy-4-fluoro-a-D-galacto-pyranosyl D-fructofuranoside), 2,3,1, 3, 4, 6 -hexa-0-benzyl-4,6-dideoxy-4,6-difluorosucrose (618), 2,3,1, 3, 4, 6 -hexa-0-benzyl-6-deoxy-6-... 

The taste properties of the di-O-methylhexopyranosyl derivatives, like those of the corresponding deoxy sugars, are never sweet, and always bitter. As with the deoxy sugars, this is possibly the result of increased lipophilicity of the molecule. In sucrose, however, the presence of two methyl groups on the D-glucopyranosyl or the D-fructofuranosyl group does not seem to cause any marked bitterness (see Table XVIII). 

Tetrachloro-4,1, 4, 6 -tetradeoxy-gaiacto-sucrose 4-Chloro-4-deoxy-a-D-galactopyranosyl l,4,6-trichloro-l,4,6- 2000... 

---