Galactitol , preparation

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. 

Deoxy-l-fluoro-L-glycerol (18) has been prepared by, among other methods, the treatment of 3,4-0-benzylidene-2,5-0-methylene-l,6-di-O-p-tolylsulfonyl-D-mannitol107 (17) with tetrabutylammonium fluoride in acetonitrile, followed by removal of the benzylidene group, periodate oxidation, reduction with borohydride, and hydrolysis. 1,6-Dideoxy-l,6-difluorogalactitol108 was obtained by treatment of 2,3 4,5-di-0-isopropylidene-l,6-di-0-(methylsulfonyl)galactitol with tetra-... 

Guan et al. have recently published the preparation of galactitol and D-mannitol-derived permethylated polyesters 62 [41] and the living ring-opening polymerization of the galactonolactone 20 [42] giving polyester 63. The latter exhibited protein resistance. 

The preparation and chemical properties of dulcitol hexanitrate were studied in detail by Hayward and McKeown [24], They found that the hexanitrate is partly denitrated by wanning to 50°C with pyridine. The denitration product was characterized as d- or L-galactitol-l,2,4,5,6-pentanitrate (m.p. 85-86°C). 

Peracetylated 1,5-anhydro-D-glucitol (41), -D-mannitol (42), -D-galactitol (43), -D-xylitol (44), -D-ribitol (65), and 2,3,5-tri-0-acetyl-1,4-anhydro-D-ribitol (66) were prepared in high yield from the corresponding glycosyl bromides on treatment with titanocene boiohydride (CpzTiBHO.193 The reaction also proceeded with... 

From this work, it follows that boronates of polyhydric alcohols can be prepared directly by heating with trialkyl- or triaryl-boranes. Galactitol heated with triphenylborane in refluxing toluene gives the same tris(phenylboronate), in 93% yield,42 as can be prepared by use of phenylboronic acid.9... 

The different reactivities of the two substituents on C-l allow selective replacement and conversion of them. Alkyl monothio-acetals [proposed as intermediates in mercury(II)-catalyzed demer-captalation reactions—see Section IV,l,b] have been prepared from a-bromothioethers by the combined action of an alcohol and silver(I) carbonate the introduction of S-nucleophiles is discussed in Section 11,6. Reduction of 81 by lithium aluminum hydride effects hydrogen-olysis of the carbon-halogen bond, whereas the action of Raney nickel on the derived S-ethyl O-methyl monothioacetal specifically cleaves the carbon-sulfur bond to afford the pentaacetate of 1-0-methyl-D-galactitol.327... 

In the second synthesis of phytosphingosine, outlined in Scheme 3, Gigg s group13 made possible the preparation of 1,3,4-tri-O-benzyl-L-galactitol 23 from D-galactose in good yield. They proved 23 to be an efficient starting material. 

A number of methyl or benzyl ether derivatives of galactitol have been prepared and converted into acetyl derivatives for mass spectral study. HN.m.r. investigation of the product obtained from chloroacetaldehyde diethyl acetal and galactitol (see Vol. 1, p. 46) has shown it to be the 1,3 4,6-di-0-acetal derivative, which on boiling with ethanolic sodium hydroxide yielded the polycyclic acetal-ether (3). ... 

Dulcitol (galactitol) [608-66-2] M 182.2, m 188-189", b 276-280"/l.lmm, pK 13.5. Crystallise dulcitol from water by addition of EtOH. It is optically inactive and is prepared by reduction of D-galactose. Its hexaacetate crystallises from EtOH and has m 168-169". [IR Thompson et al. Discuss Farad Soc 9 222 1950, Wolfrom Thompson Mei/zods in Carbohydrate Chemistry II611963, Academic Press, Beilstein 1IV 2844.]... 

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