Benzylidene sorbitol

The same anhydride of mannitol has been obtained recently by the deamination of 1-amino-l-desoxy-D-mannitol.8 It is interesting to note that this method of formation of anhydro rings is of fairly general application. Thus 1,4-anhydro-D-sorbitol is obtained from 1-amino-l-desoxy-D-sorbitol. Similarly, methyl 2,3-anhydro-4,6-benzylidene-a-D-manno-pyranoside and methyl 2,3-anhydro-4,6-benzylidene-a-D-allopyranoside9... 

Chloro-6-desoxy-3,5-benzylidene-l,4-anhydro-D-sorbitol (XVI) possesses an unusual property in that the benzylidene group is removed by distillation in alkaline or neutral solution. From the neutral solution it was possible to isolate 6-chloro-6-desoxy-l,4-anhydro-D-sorbitol as its triacetyl derivative. At the same time diacetyl-1,4 3,6-dianhydro-D-sorbitol was also formed. This removal of an acetal residue from a... 

Anhydro-L-iditol (XLIII) has been obtained by Vargha41 by a very interesting method from l,6-ditosyl-2,4-benzylidene-D-sorbitol (XLIV). This compound, on treatment with one molecular proportion... 

The rings in l,4 3,6-dianhydro-D-sorbitol have different stabilities. Montgomery and Wiggins66 treated the anhydride with hydrochloric acid under pressure and isolated some l,6-dichloro-l,6-didesoxy-D-sorbitol and much 6-chloro-6-desoxy-l,4-anhydro-D-sorbitol, both isolated as their benzylidene derivatives. No l-chloro-l-desoxy-3,6-anhydro-D-sorbitol was found. This experiment demonstrates that the 1,4-anhydro ring is more stable than the 3,6-ring in this substance. This is in agreement with the fact that partial dehydration of D-sorbitol in the 1,4-position can be preferentially effected and 1,4-anhydro-D-sorbitol isolated. 

L-Iditol (sorbi6rite), the last of the four naturally occurring hexitols, occurs in service berries along with sorbitol. After removing sorbitol from the juice by fermentation to L-sorbose with the sorbose bacterium, Acetobacter xylinum, the n-iditol is crystallized as a benzylidene derivative. It has been prepared by the action of sodium amalgam on... 

Iodo-desoxy derivatives of methylene, benzylidene and isopropylidene compounds have been transformed into their desoxy analogues with Raney nickel and hydrogen in basic media (e.g. hydroxides, methoxides and diethylamine). 0 47,60,81,82 Under similar conditions, l,3 2,4-diben-zylidene-5,6-sorbitoleen has been hydrogenated 8 and 2,4-benzylidene-6-nitro-6-desoxy-D-sorbitol has been converted into the corresponding amine.84 We are not aware of any report in this field of the removal of a benzylidene group by Raney nickel, as is the case with certain sugar derivatives.88... 

When the benzylidenation of sorbitol is carried out under slightly different conditions, a dibenzylidene-D-sorbitol (m. p. 219-221°, after purification via its dibenzoate) is obtained.29 116 Wolfe, Hann and Hudson29 demonstrated that oxidative scission of the diacetal resulted in the consumption of one molecular equivalent of lead tetraacetate and in the production of formaldehyde, together with a dibenzylidene-aldehydo-pentose, which yielded L-xylose when heated with aqueous... 

There are appreciable discrepancies in the values quoted for the melting point of the triacetal which results from the complete benzyli-denation of D-sorbitol. The highest recorded figure seems to be 203°, the value reported by Angyal and Lawler.137 The same authors proved that the benzylidene residues were disposed 1,3 2,4 5,6 by identifying l,3 2,4-dibenzylidene-D-sorbitol as a hydrolysis product.137... 

A second monobenzylidene-D-sorbitol (m. p. 132-133°) has been prepared by Sowden 68 it is the 4,6-acetal, which was produced by hydrogenation of the known 4,6-benzylidene-D-glucose, and which gave 2,4-benzylidene-D-erythrose when subjected to periodate oxidation. 

Vargha186 obtained a l,6-dibenzoyl-2,3,4,5-dibenzylidene-D-sorbitol from both 1,6-dibenzoyl-D-sorbitol and l,6-dibenzoyl-2,4-benzylidene-D-sorbitol, by treatment with benzaldehyde and zinc chloride. The crystalline dibenzylidene-D-sorbitol (m. p. 208°) which was derived by debenzoylation of Vargha s product was termed 2,4 3,5-dibenzylidene-D-sorbitol by Haworth, Gregory and Wiggins,133 but we feel that additional information should be furnished before the 2,3 4,5- and 2,5 3,4-structures are finally eliminated. 

The acetonation of 2,4-benzylidene-D-sorbitol has been studied by Vargha135 and by Laan and Dekker 88 when copper sulfate is employed as the catalyst a mono- and a di-isopropylidene derivative (m. p. 179° and 131°, respectively) are obtained. An interesting point about the latter compound is that, unless acetal rearrangement occurs during the acetonation stage, it must contain at least one isopropylidene group which is not united to adjacent positions in the hexitol molecule. 

A typical formulation for a polypropylene (PP) film used for wrapping biscuits would be PP 100 pph pentaerythritol tetrakis[3-(3,5-di-tertbutyl-4-hydroxyphenyl) propionate] 0.1 pph phosphorous acid, tris(2,4-di-tert-butylphenyl)ester 0.1 pph emcamide 0.05 pph. Nucleators, such as substituted benzylidene sorbitols, can be added to improve the clarity of PP and LDPE (see Eig. 10.4). Oriented polypropylene (OPP) films are also available where a higher transparency is required with improved strength. 

Yamasaki, S., Tsutsumi, H. (1994). Microscopic studies of l,3 2,4-di-(9-benzylidene-D-sorbitol in ethylene glycol. Bull Chem. Soc. Jpn., 67 906. 

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