Other Cyclitol Derivatives

7 Other Cyclitol Derivatives. - The distribution of products in the gas-phase acid-induced ring-opening with methanol, as well as condensed phase meth-anolysis, of cyclohexene oxides e.g. 220) bearing remote O-functionality has been studied. Products and ratios varied widely depending on the reaction phase. 

D-Glucose-derived radical precursors 225 and 226 have been subjected to carbocyclization reactions to yield cyclic polyol derivatives in enantiomerically pure form. They underwent 6-exo-trig and 7-exo-dig radical cyclizations upon treatment with tributyltin hydride and AIBN to give the cyclo-hexitol and -heptitols, 227 and 228 respectively, in moderate yields.  

Sakamoto, K. Ichimura and H. Ohrui, Biosci. Biotechnol. Biochem., 2000, 64, 1915. 

Leclercq, C. Dubertret, B. Pitard, D. Scherman and J. Herscovici, Bioorg. Med. Chem. Lett., 2000,10,1233. 

Le Merrer, L. Gauzy, C. Gravier-Pelletier and J.-C. Depezay, Bioorg. Med. 

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D-Quercitol (73) is common in members of the genus Quercus, oaks, of the family Fagaceae. This cyclitol derivative is known from at least nine other families. D-Pinitol (63) is known from six families of gymnosperms, in which it is widespread, but it is also known from a number of angio-sperms. 

Many other cyclitols and derived compounds are themselves achiral, but are capable of giving rise to chiral derivatives when suitably substituted. One of the best studied examples is deoxystreptamine, which occurs as substitution products in antibiotics of the Kananycin-neomycin type. See p. C3 and also M. Hichens and K. L. Rinehart, J. Amer. Chem. Soc., 1963,85, 1547. 

Among the four cyclitol derivatives were isolated from a Korean SteUetta sp., three have already been isolated from two other sponges from Korea, a Petrosia sp. (Haploscler-ida) and a Sarcotragus sp. (Dictyoceratida) and the fourth, norsarcotride A is new (Zhao et al, 2003b). This suggests... 

In the last twenty years, nitro sugars became powerful chemical tools on account of their usefulness for the construction of carbon-carbon bonds prior to the transformation of the nitro group into a variety of other chemical functionalities. As a result, a diverse range of funcionalized carbohydrates and other derivatives as carbasugars, cyclitols and heterocycles have been prepared. 

Other avenues of research were not ignored, however, as is indicated by the preparation of the first furanose-related glycal and the study of inversions in the cyclitol series by treatment of their esters with liquid hydrogen fluoride. Then, in the mid-sixties, Dr. Fletcher began to turn to the chemistry of acylamidodeoxyhexoses. Together with Drs. Nevenka Pravdic and T. D- Inch, he prepared 1,2-ox-azoline derivatives of such carbohydrates. This led to a method for... 

Cyclohexylidene derivatives of 1,2-diob. Whereas 1,2-diols had traditionally been characterized by reaction with acetone to produce the acetonide or isopropylidene derivatives, Micovic and Stojiljkovic recommended conversion of sugars and other polyols into their cyclohexylidene derivatives because of the ease with which these substances crystallize. Angyal et al. explored the behavior of inositol (1) and found that this cyclitol gradually dissolved in a mixture of cyclohexanone and benzene containing p-toluenesulfonic acid on boiling under a Dean-Stark water separator. 

It has often been assumed that any cyclitol having two cts-l,2-diol structures will react with acetone to give a diacetal. However, the dinitro-tetrol (106) affords only a monoacetal, for steric reasons. b. Diaminocyclohexanetetrols.— The dinitrotetrol (106), on reduction, gave the corresponding diaminotetrol. The conversion of dibromotetrols into diaminotetrols has been mentioned. Other methods include the reduction of a nitroaminotetrol derivative and of rhodizonic acid diimine (108). ... 

In addition to methods employing nuclear magnetic resonance and optical rotation, numerous other physical methods have been applied to cyclitols or their derivatives. 

Other carba disaccharides to have been prepared include carba-a-o-Glcp-, carba-a-D-Manp-, carba-P-D-Man/j- and carba-P-o-GIcNAcp- (l- 4)-l,6-anhydro-2,3-0-isopropylidene-P-D-mannopyranoses. The a-linked compounds were prepared by adding the anion of l,6-anhydro-2,3-C>-isopropylidene-p-D-mannopyranose to epoxide 98 and the P-linked derivatives were obtained from the a-linked compounds by epimerization after oxidation of the free cyclitol OH group. Further standard transformations of the free cyclitol OH also gave the cyclitol configurations noted above.In a similar way, opening of a cyclitol... 

Other Unsaturated Compounds. - The dienals 13 (with D-xylo-, D-lyxo- and D-arahino-configurations) have been condensed with the phosphonate 14 to give the enone adducts 15 the intramolecular Diels-Alder reactions of these adducts are mentioned in Chapter 22. Treatment of the unsaturated lactone 16 with the Tebbe reagent has afforded 17 its conversion into a cyclooctene derivative is covered in Chapter 18. Exposure of the cyclic sulfate 18 to base has afforded a mixture of the exo- and endo-olefins 19 and 20, ° and a syn-selective dihydroxyla-tion of the 3,4-unsaturated pyranoside 21 generated predominantly the D-allo product. Synthesis of the branched-chain 5,6-ene 22 using standard methods, and its conversion into a cyclitol during the first total synthesis of (—)-tetracyc-line is mentioned in Chapter 22. 

The di(benzyloxy)cyclohexene (9) mentioned above has also been used to synthesize racemic deoxyinosamine, deoxyinosadiamine, and inosamine derivatives via the unsaturated inosamine derivatives (16) and (17) Scheme 5 illustrates the basic sequences that were applied to both isomers. The same group has similarly prepared racemic amino-cyclitols from 3-benzyloxycyclohexene, and 3-methoxycyclohexene was used for a synthesis of the peracety-late d DL - 2,5 - diamino -2,3,5- trideoxy-4 -0-5-N- dimethyl - ch iro - inositol (18). Base-catalysed cyclization of the substituted diones (19) gave the corresponding cyclitols (20), which were then used to prepare other 2,l -substituted cyclitols including mono- and di-amino-cyclitols, e.g., (21). ... 

In view of the wide distribution of the cyclohexanehexols (called inositols or cyclitols) and the importance of one in particular (myo-inositol) to certain bacteria, plants, and perhaps even to warm-blooded animals, the naturally occurring and synthetic compounds of this carbocyclic class have received considerable study. Naturally occurring members include four inositols, monomethyl ethers, a dimethyl ether, monodeoxy derivatives, one dideoxy derivative, a methyl homolog, and deoxy carboxylic acids. Five inositols and many other synthetic members, including ketones (cycloses or inososes), are known. 

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