D-Altritol

Fig. 2. Structures of hexitols (a) allitol, (b) sorbitol (D-glucitol), (c) D-maimitol, (d) dulcitol, (e) L-iditol, and (f) D-altritol.

For the synthesis of C2-symmetric 1,4-diol, Evans planned temporary silicon-tethered ring-closing metathesis, and asymmetric synthesis of D-altritol was... 

Baddiley and coworkers13 further found that, under the same conditions (100° and 2 M hydrochloric acid), allitol (9) and D-altritol (D-talitol) (10) are converted into anhydrides in high yield, as shown... 

This second approach70 was based on the nitromethane synthesis,71 and involved, as the key intermediate, l-C-nitro-l-hexene-D-n6o-3,4,5,6-tetrol tetraacetate (66), previously reported by Sowden and Fischer.77 In re-studying their conversion of D-ribose (64) into the hexenetetrol (66), it was possible70 to secure 2,3,4,5,6-penta-O-acetyl-l-deoxy-l-nitro-D- altritol (65) as crystalline material. When (65) was subjected to the Schmidt-... 

The gas —liquid chromatographic re-run of zone A at 180° (see Fig. 10) indicated the presence of two zones, in almost equal proportions, which were presumed to be tetra-0-acetyl-l,5-anhydro-3-deoxy-3-C-(hydroxymethyl)-D-glucitol and -D-altritol, although no definite synthetic evidence has thus far been presented in support of this supposition. 

SCHEME 13.84 Defoin s synthesis of 2,5-iniino-2,5,6-trideoxy-D-altritol. 

The stereochemistry of the alditols formed by reduction of the aldehyde group is instructive. In the pentose series, xylitol and ribitol are meso forms, whereas D-arabinitol and D-lyxitol are identical. In the hexose series, allitol and galactitol are meso forms, and D-altritol and D-talitol are identical, as are D-glucitol and L-gulitol. 

Alditol derivatives containing non-terminal double bonds have also been reported. Treatment of 1,2 5,6-di-0-isopropylidene-3,4-di-O-p-tolylsul-fonyl-D-mannitol with sodium benzoate in iV,A -dimethylformamide afforded, in addition to saturated products of displacement, 3-deoxy-1,2 5,6-di-0-isopropylidene-4-0-p-tolylsulfonyl-D-(/ireo-hex-3-enitol and the corresponding tetrol formed by hydrolysis of the acetal rings. 1,2 5,6-Di-O-isopropylidene-D-mannitol and -D-altritol have been converted into the trans and cis isomers, respectively, of 1,2 5,6-di-O-isopropylidene-3,4-dideoxy-D-(/irco-hex-3-enitol by the thionocarbonate method. ... 

Evans and Murthy used RCM of enantiomerically enriched allylic alcohols tethered through a silicon atom to prepare the reduced carbohydrate D-altritol 390 [164]. Treatment of diphenylsilyl acetal 391 with Grubbs catalyst 385 in CH2CI2, heating at reflux, provided the C2-symmetrical silacycle 392 in excellent yield. Dihydroxylation of the cis-olefin and simple manipulations led to a facile, expeditious route to D-altritol (Scheme 10-126). 

A new synthesis of 2,5-anhydro-D-altritol (25) and the first synthesis of 2,5-anhydro-D-idltol (26) have been reported, both from 2,5-anhydro-D-mannltol (27), by conventional routes outlined in Scheme 9... 

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