Deoxy sugars 3.6- dideoxy hexoses

The paper-chromatographic properties of the common deoxy and dideoxy sugars have been treated in several reviews,2 28 a book,829 and individual publications. Common solvent-systems are 6 4 3 1-butanol-pyridine-water (Solvent A) 4 1 5 1-butanol-acetic acid-water (Solvent B) and 1-buta-nol-ethanol-water (4 1 5, upper phase, Solvent C or 3 1 1, Solvent D). The four 2-deoxy-D-hexoses and the 2,6-dideoxyhexoses may be separated as their borate complexes. 0 The use of 1-butanol-water on the one hand, and of 2-butanone-borate buffer on the other, usually provides adequate separation and, by use of a combination of solvents, these deoxy sugars may be identified. 80 The use of buffered systems has proved highly advantageous in the separation and identification of the isomeric 6-deoxy-hexoses.8 1 Other systems, such as Solvent A and 2 1 2 ethyl acetate-... 

Hydride reduction of methyl 3-deoxy-3- dimethylamino)-2,4,6-tri-O-p-tolylsulfonyl-a-D-rtho-hexopyranoside in tetrahydrofuran gave the corresponding 6-deoxy sugar which, on hydrolysis, afforded 3,6-dideoxy-3-(dimethylamino)-j8-D-riho-hexose this was found to be identical witii mycaminose, a component of an antibiotic substance. Syntheses of 4,6-dideoxy-3-0-methyl-D-xyi o-hexose (chalcose) have been reported by the intermediate hydride reduction, in tetrahydrofuran, of 6-p-toluenesulfonates methyl 4-deoxy-6-0-p-tolylsulfonyl-a-D-xy/o-hexopyranoside afforded, by such treatment, the corresponding 6-deoxy glycoside, and methyl 4-deoxy-3-0-methyl-2,6-di-O-p-tolylsulfonyl-a-D-xi/Zo-hexopyranoside gave a mixture of five products, from which methyl a-D-chalcoside was isolated in 26% yield. 

Among the 2-deoxy sugars found as the carbohydrate portion of cardiac glycosides and other glycosides in plants are o-cymarose (2,6-dideoxy-3-(9-methyl-D-n7 o-hexose) (12), D-sarmentose (2,6-dideoxy-3-(9-methyl-o-xy/c>-hex-ose) (13), L-oleandrose (2,6-dideoxy-3-0-methyl-L-am m< -hexose) (14), o-diginose (2,6-dideoxy-3-(9-methyl-o-/yxo-hexose) (15), o-digitoxose (2,6-dideoxy-D-nZ o-hexose) (16), and o-boivinose (2,6-dideoxy-o-xy/o-hexose) (17) (Courtois and Percheron, 1970). 

P2j Z = 2 D = 1.17 R = 0.080 for 3,888 intensities. This is aconfigu-rational analysis of the macrolide antibiotic 23672RP from Streptomyces chryeus. All three sugar residues are pyranoid the conformation of the a-ketose is CX, with Q = 56 pm, 0 = 9° that of the / -D-mycinose (6-deoxy-2,3-di-0-methyl-D-allose) is 4Clt with Q = 59 pm, 0 = 6° and that of the / -L-mycarose (2,6-dideoxy-3-C-methyl-L-riho-hexose) is 1C4, with Q = 53 pm, 0= 177°. The O-5-C-l-O-l-C glycosidic torsion-angles are —71, —87, —83°. The atomic coordinates reported in the paper refer to the opposite enantiomer. 

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