Ribitol 5-deoxy-2,3-0-isopropylidene

D-Ribono-1,4-lactone (1) readily condenses with acetone, under acidic catalysis with mineral acids or anhydrous copper sulfate, to give 2,3-0-isopropylidene-D-ribono-1,4-lactone (16a), which was employed for the synthesis of 5-deoxy and 5-0-substituted derivatives of D-ribono- 1,4-lactone and D-ribitol (24). Acid removal of the 1,3-dioxolane protecting group gave products having probable inhibitory activity of arabinose 5-phosphate isomerase (25). Other applications of 16a for the synthesis of natural products will be discussed later. 

The isocyanide method of reduction has been applied successfully for preparing a series of diversely protected 1,4-anhydroalditols 188 l,4-anhydro-5-O-tert-butyldimethylsilyl-2,3-0-isopropylidene-D-ribitol (56, 81%), l,4-anhydro-5-0-terf-butyldimethylsilyl-6-deoxy-2,3-0-isopropylidene-D-allitol (57,87%) and -l-talitol (58,87%), 1,4-anhydro-2- 0-rert-butyldimethylsilyl-3,5- 0 -isopropylidene-... 

Acetamido-5-deoxy-D-threo-pentulose and 5-acetamido-5-deoxy-L-erythro-pentulose (204) are obtainable by the bacterial oxidation of 1-acetamido-l-deoxy-D-arabinitol and 1-acetamido-l-deoxy-D-ribitol, respectively. Both ketoses are crystalline, and show a strong carbonyl vibration in their infrared spectra. Accordingly, they exist in the acyclic form. Their isopropylidene acetals are likewise acyclic. Furthermore, 5-acetamido-5,6-dideoxy-L-xylo-hexulose (205), obtainable by bacterial oxidation, shows a great tendency to assume the acyclic structure. 5-Acetamido-5-deoxy-L-xi/io-hexulose (206) may be obtained by the bacterial oxidation of 2-acetamido-2-deoxy-D-glucitol it assumes, exclusively, the sterically more-favored pyranose form. ... 

Deoxy-l,2-0-isopropylidene-a-D-eryi/iw -pentofuranoside, D-346 5-Deoxy-1,2- O -isopropylidene-a-D-eryi/iro -pentofuranos-3-ulose, P-43 5-Deoxy-1,2- O -isopropylidene- -ly-threo -pentofuranos-3-ulose, D-337 5-Deoxy-l,2-0-isopropylidene-p-L-//ireo -pentofuranos-3-ulose, D-337 5-Deoxy-2,3-0-isopropylidene-D-ribitol, D-356 l-Deoxy-3,4-0-isopropylidene-L-ribitol, D-356... 

Deoxy-2,4 3,5-di- O -methylene-D-Jtylitol, D-385 l-Deoxy-2,4 3,5-di-0-methyIene-L-xylitol, D-385 l-Deoxy-2,4 3,5-di-0-methyIene-DL-xylitoI, D-385 l-Deoxyiditol D-form, D-237 5-Deoxy-2,3-0-isopropylidene-i>ribitol, D-356 l-Deoxy-2,4-0-methylene-3,5-di-0-tosyI-D-xylitol, D-385 1 -Deoxy-2,4-O -methylene-5-O-tosyI-r>-xylitol, D-385 l-Deoxy-2,4-methylene-D-xylitol, D-385 1-Deoxyribitol D-form, D-356 1-Deoxyribitol D-form, D-356... 

A -bis(2-chloroethyl phosphordiainidate R at phosphonis), l,4-anhydro-4-deoxy-2,3-0-isopropylidene-4-[(/ )-methoxyphosphinyl)-L-ribitol 52, 22 and glycosyl phosphonate 53.123 jjjg phosphonamidate 54 has been characterized by X-ray analysis. 

The syntheses of the fluoro-l,5-imino-D-glucitol 30 and fluoro-l,5-imino-D-ribitol 31 by conventional chemistry from L-sorbose and 5-amino-5-deoxy-2,3-isopropylidene-D-ribonolactam respectively have been reported. ... 

Alditols, Cyclitols and Derivatives Thereof. - 2,5 3,4-Dianhydro-D-altritol, 2,5-aohydro-3,4-0-(l,2-ethanediyl)-D mannitol, pentaerythritol tetraacetate, ribitol tetraacetate, xylitol tetraacetate, D-arabinitol tetraacetate, D, L-arabinitol tetraacetate, 2,4 3,5-di-0-isopropylidene-D-mannitol, 2 hexa-O-acetyl-D-mannitol, allitol hexaacetate, D-mannitol hexaacetate, D, L-mannitol hexaacetate, D-iditol hexaacetate, D, L-iditol hexaacetate, D, L-glucitol hexaacetate, D, L-altritol hexaacetate, L-galacto-D-galacto-decitol (which is C2-symmetric), 5 6-0-benzyl-2,3-0-[(S)-caniphanylidene]-l,4,5-tris-0-pivaloyl-D-myo-inositol, 6D-3,6-di-0-benzyl-l-0-[(S)-camphanyl]-2-deoxy-2,2-difluoro-4,5-0-isopropylidene- y< -inositol, cyclopentane 28. ... 

---