D-Galactitol

L-Fucitol (l-Fuc-oI) or 1-deoxy-D-galactitol not 6-deoxy-L-galactitol (cf. 2-Carb-2.2.3.1)... 

Support for this result was obtained from the taste of 1,5-anhydrohexitols, which, only for purposes of comparison, can be regarded as 1-deoxyal-dopyranoses. 1,5-Anhydro-D-glucitol (that is, the incorrectly named 1-deoxy-D-glucopyranose ) (14), 1,5-anhydro-D-mannitol ( 1-deoxy-D-mannopyranose or 2-deoxy-D-fructopyranose ) (15), and 1,5-anhydro-D-galactitol ( l-deoxy-o-galactopyranose ) (16) are all purely sweet, without any trace of bitterness. Furthermore, the complete absence of bitterness of 1,5-anhydromannitol (16) clearly indicates that the anomeric... 

D-Galactose diethyl thioacetal pentaacetate to l-desoxy-D-galactitol ... 

Naphthyl l-thio-/J-D-galactopyranoside tetraacetate to 1,5-anhydro-D-galactitol tetraacetate... 

Extended irradiation of the diethyl dithioacetal 44 increases the yield of L-fucitol (46) at the expense of 1-S-ethyl-l-thio-D-galactitol (45) also galactitol (52) was isolated from the photolysis mixture.109 The intermediacy of 45 in the formation of 46, a possibility that was suggested by the extended photolysis of 44, is supported by the observation that irradiation of 45 in methanol produces L-fucitol (46) in 44% yield.109 (Compounds 47 and 52 also are formed during irradiation of 45, but in low yield.) The mechanism for sulfide photoreaction parallels that109 for the alkyl dithioacetals (see Scheme 18). 

Scheme 20.—Potential, Photochemical-Reaction Pathways for Reaction of 1-Deoxy-l-(ethysulfinyl)-D-galactitol (47).

H. Paulsen, Y. Hayauchi, and V. Sinnwell, Monosaccharides containing nitrogen in the ring. XXXVII. Synthesis of l,5-dideoxy-l,5-imino-D-galactitol, Chem. Ber., 113 (1980) 2601-2608. 

Linear [ ]-pol3turethane derived from 1-deoxy-l-isocyanate-2,3 4,5-di-(9-iso-propylidene-D-galactitol (prepared from 48) in the presence of TEA or Zr(acac)4, as well as its corresponding polyhydroxy derivative obtained by hydrolysis of the acetal protecting group, have been prepared [117]. They are semicrystalline materials that exhibit high melting temperatures and thermal stability up to 230°C. 

Several routes to 1-deoxygalactonojirimycin (5) have been published to date. l,5-Dideoxy-l,5-imino-D-galactitol (5), the epimer of 1-deoxynojirimycin (1) at C-4, was st synthesized by Paulsen and co-workers in 1980 [24]. These workers employed 1,6-anhydro- a-o-galactofuranose (6) as the starting material. 

The precursor to (5) was made diastereoselectively by Fessner and coworkers [44]. When the intermediate ketose 1-phosphate was immediately submitted to hydrogenation conditions, l,5,6-trideoxy-l,5-imino-D-galactitol (1,6-dideoxygalactonojirimycin, 10) was obtained in fair yield [42]. The latter derivative was also obtained by a hetero Diels-Alder cycloaddition of a benzyloxycarbonyl nitroso dienophile to ( , )-sorbaldehyde dimethylacetal [45]. 

Proton coupling-constants were determined65 for the tri-O-acetyl derivatives of bis(ethylsulfonyl)-a-D-lyxopyranosylmethane [2,6-anhydro-l,l-bis(ethylsulfonyl)-l-deoxy-D-galactitol] (29) and bis(eth-... 

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