1,2-O-Isopropylidene-D-glucofuranose

O-isopropyliden-D-glucofuranose erhalt man z.B. in 55%iger Ausbeute 6-Desoxy-... 

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-... 

The mass spectra of methyl 3-deoxy-p-v-tkreo-pentopyrano-side, methyl 4-deoxy-j3-T>-thieo-pentopyranoside, and 5-deoxy-fi-D-xylo-furanoside are discussed and compared fragmentation paths are sufficiently different to allow identification on the basis of their mass spectra. On the other hand, the mass spectra of methyl 2- and 3-deoxy-5-O-methyl-f3-i>-erythro-pentofuranosides do not exhibit fragmentation differences. The mass spectra of 3-deoxy-l,2 5,6-di-O-isopropylidene -d-xylo - hexofuranose, 5- deoxy -1,2-0-isopropylidene-D-xy o-hexofuranose, and 6-deoxy-l,2-0-iso-propylidene-D-glucofuranose show prominent differences, even between the 5- and 6-deoxy isomers. The interpretation of the spectra was aided by metastable-ion peaks, mass spectra of DzO-exchanged analogs, and the mass spectrum of an O-isopropylidene derivative prepared with acetone-d6. 

A novel synthesis of D-glucose 6-phosphate (in 55% yield) has been reported it involves alcoholysis of the cyclic phosphate of catechol with 1,2-O-isopropylidene-a-D-glucofuranose, followed by acid hydrolysis of the so-formed phosphoric diester.192 The reagent... 

In contrast to the oxidation of acyclic polyhydric alcohols in benzene,508 treatment of 1,2-O-isopropylidene-a-D-glucofuranose with silver carbonate-on-Celite in boiling methanol led to selective oxidation of the primary hydroxyl group, with the formation of the al-duronic acid derivative in 68% yield.517... 

Bakke and Theander132 described an interesting, new synthesis of L-ascorbic acid by one-step oxidation of 1,2-O-isopropylidene-a-D-glucofuranose to l,2-0-isopropylidene-a-D-xyfo-5-hexulofuranurono-6,3-lactone hydrate (74), followed by hydrolysis of the isopropyli-dene group, and specific, borohydride reduction of the aldehyde group liberated. 

Hydrolysis of 5,6-anhydro-l,2-0-isopropylidene-a-D-glucofuranose with sodium hydroxide under controlled conditions can lead71-74 to both 3,5-anhydro-l,2-0-isopropylidene-/3-L-idofuranose and 3,6-anhydro-l,2-0-isopropylidene-a-D-glucofuranose, in addition to 1,2-O-isopropylidene-a-D-glucofuranose (see p. 130), whereas mild hydrolysis with 5 mM sulfuric acid can give up to 25% of 2,5-anhydro-L-idose (62), besides the expected D-glucose.195 This reaction must in-... 

Nitrogen-containing bases have been used to bring about partial deprotection of carbohydrate nitrates. Considerable selectivity was achieved in the reaction245 of 6-0-acetyl-l,2-0-isopropylidene-a-D-glucofuranose 3,5-dinitrate in benzene solution with a 30% solution of dimethylamine in ethanol, from which 1,2-O-isopropylidene-a-D-glu-cofuranose 5-nitrate was isolated in 47% yield. 

An alternative synthesis468 of L-idonic acid is shown in Scheme 15. On oxidation with periodate, 1,2-O-isopropylidene-a-D-glucofuranose (56) yields the protected dialdose 91. When 91 is treated with hydrogen cyanide, a mixture (92) of the Q-gluco and L-tdo nitriles results, with the D-gluco nitrile preponderating. Hydrolysis affords L-iduronic... 

O-isopropylidene-a-D-glucofuranose by zinc methoxypropanol complex catalyst, J. Polym. Sci., Part A Polym. Chem., 22 (1984) 3593-3598. 

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