Pentodialdoses

K. P. Gable and G. A. Benz, Rhodium (I)-catalyzed cyclizations of 3-C-alkenyl pentodialdose derivatives, Tetrahedron Lett. 32 3473 (1991). 

Photolysis of D-glucose in methanol containing titanium(IV) chloride gave the D-xy/o-pentodialdose glycoside acetal 184 in 60% yield D-galactose behaved similarly.386... 

I. Kovacs, Z. Toth, P. Herczegh, and F. Sztaritskai, Pentodialdose mercaptal derivatives new chiral C5 synthetic building blocks, Tetrahedron Asymmetry, 4 (1993) 2261-2264. 

The oxidation of 1,2-O-isopropylidene-D-glucofuranose with lead tetraacetate was found by Criegee to yield formaldehyde,43 which confirmed the presence of a furanose ring in the sugar derivative. The major oxidation fragment, l,2-0-isopropylidene-5-oZde/q/do-D-a yZo-pentodialdose, was characterized subsequently by Iwadare,88 and has recently been shown to crys-... 

In the preparation of polyhydroxylated azepane as potential glycosidase inhibitors, Dha-vale [28] described a short synthetic route utilizing the Henry approach. The nitroaldol reaction of l,2-0-isopropylidene-3-0-benzyl-a-D-xylo-pentodialdose 36 and nitromethane in the presence of triethylamine at room temperature afforded a-D-gluco- and /3-L-ido- nitroal-dose 37, the precursors to (2S, 3R, 4R, 5R) and (2S, 3R, 4R, 55) tetrahydroxyazepanes 38 and 39, in a 88 12 ratio in 95% yield (O Scheme 13). 

An intriguing and important adaptation of the aldose-nitromethane reaction was also studied in Toronto by Fischer and Jean Grosheintz. By addition of nitromethane to 1,2-0-isopropylidene-n-a 2/fo-pentodialdose and subsequent hydrolysis of the acetone group, they obtained a mixture of 6-deoxy-6-nitro-D-glucose and 6-deoxy-6-nitro-L-idose. A second, intramolecular reaction of these substances led to a mixture of deoxynitro-inositols and, by reduction, to the related aminodeoxyinositols. One of the latter was successfully deaminated a few years later, by T. Posternak, to the B-vitamin, mt/o-inositol (12), thus completing a synthesis of the latter that started from n-glucose. 

The Weerman degradation was employed in one of the first preparations of dialdoses, namely of n-f/ireo-tetrodialdose, using the diamide of D-glucaric acid as starting material. An inosose has been degraded to a pentodialdose by way of its disulfone and the Nef reaction, transformation of a 6-deoxy-... 

The isopropylidene acetal of ii/fo-pentodialdose has been used as the starting material for many syntheses. In later preparations, oxidation with sodium metaperiodate was employed. " The preparation of the compound in a crystalline state, as reported by Brocca and Dansi and by Schaffer and Isbell was a considerable improvement in its further use as a starting material. (The sirupy product previously used was not completely satisfactory for syntheses as it always contained some formaldehyde from the glycol oxidation.) The compoimd crystallized as a hydrate and could also be obtained anhydrous - by recrystallization from benzene. 

Some other derivatives of xylo-pentodialdose (8) have been obtained by... 

Wolfrom and Hanessian recently prepared a 3-0-benzyl derivative of xj/io-pentodialdose by oxidation of 3-0-benzyl-l,2-0-isopropylidene-a-D-glucofuranose with lead tetraacetate in benzene. The compound was characterized as the crystalline semicarbazone. 

Finally MacDonald and Fischer have prepared the free ajyZo-pento-dialdose (8) by the sulfone-degradation method. The diethyl dithioacetal of scyllo-inosose (12) was oxidized to the corresponding disulfone which, on treatment with ammonia, gave the dialdose (8). The structure was proved by converting the compound into the bis(ethylene dithioacetal) derivative, which was identical with that obtained from a /io-pentodialdose prepared by a previous method. ... 

There is evidence that a bis(phenylhydrazone), which could be isolated in low yield from the products of bromiue treatment of silver (methyl a-D-galactosid)uronate, is a derivative of L-arabino-pentodialdose. ... 

MacDonald and Fischer prepared D- fluco-hexodialdose (27) by two different methods. By use of the Nef reaction, 6-deoxy-l,2-0-isopropyli-dene-6-nitro-n-glucose (26) was converted into the dialdose (27), which was isolated from the aqueous solution as its insoluble, crystalline bis-(diethyl dithioacetal) (in 48% yield, after recrystallization). It is of interest to note that the starting material (26) is one of the two isomeric 6-deoxy-6-nitro sugars which Grosheintz and Fischer prepared from 1,2-0-iso-propylidene-a-D-x2/lo-pentodialdo-l, 4-furanose (7). Thus, the synthesis discussed here is an ascent from a pentodialdose to a hexodialdose. 

Mester and M6czdr prepared the formazan of 1,2-0-isopropylidene-a-D-a 2/Zo-pentodialdo-l, 4-furanose and the bis(formazan) of the free xylo-pentodialdose (see Hester s review ). 

The reaction sequence of Grosheintz and Fischer,98,102 namely, 87 — 88 + 89 — 90 + 91 — 100 + 101 +102, constitutes a stepwise, nitromethane cyclization of xylo-trihydroxyglutaric dialdehyde (99) (xy(o-pentodialdose), a partially protected derivative of which is 87. 

In analogy to the nitromethane cyclization of pentodialdoses already discussed, a derivative of meso-tartraldehyde, namely, the hemialdal (124) of 2,3-O-cyclohexylidene-eryfhro-tetrodialdose, has furnished119 a mixture of stereoisomeric 2,3-0-cyclohexylidene-5-nitrocyclopentane-1,2,3,4-tetrols (125). 

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