N-Mannitol

Dianhydro-n-mannitol or isomannide was first prepared many years ago by Fauconnier44 who obtained it by heating D-mannitol with hydrochloric acid. The dianhydrides of D-sorbitol and L-iditol were not prepared, however, until very recent times. Although isomannide is a crystalline substance forming well defined derivatives very little work has been carried out on it and its structure was not determined until 1945, but in that and the following years a flood of experiments having a... 

Aliphatic ethers have not been formed selectively, but Irvine and Patterson found that, with silver oxide and methyl iodide, it was not possible to introduce the sixth methyl group, on hydroxyl 1, into partially methylated n-mannitol obtained by reducing methylated n-mannose. However, n-mannitol can be completely methylated with dimethyl sulfate and sodium hydroxide in carbon tetrachloride. "... 

J. C. Irvine and Bina M. Patterson, J. Chem. Soc., 106, 916 (1914). The methylated n-mannose was prepared from or-methyl n-mannoside, which the authors thought to be furanoid. The ether was reported as 2,3,5,0-tetramethyl-n-mannitol, but, since the starting n-mannoside is now known to have been pyranoid, the ester must be 2,3,4,6-tetramethyI-n-mannitol. 

A low-calorie, noncariogenic sweetener suitable for diabetics is described. It comprises (fructosyl).sub.n mannitol or (fructosyl).sub.n sorbitol (n = 1 to 6), or a mixture of these compounds, and a process for its preparation. Jerusalem artichoke tubers can be used as a raw material. 

As mentioned earlier, there has been no lack of attempts at synthesis in the oyclitol field. Work in this direction led Micheel to an ingenious syntheds from n-mannitol of a tetrahydroxycyclohexane which he named tetrahydroxymannocyclitol. The starting product was the previously... 

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