HIGHER POLY-HYDROXY ALCOHOLS

The di-hydroxy and the tri-hydroxy derivatives of the saturated hydrocarbons which have been studied thus far are  

As previously stated, it is generally true that stable compounds do not result when more than one hydroxyl group is linked to one carbon atom. It is plain therefore that the simplest member of each class of poly-hydroxy substitution products must have as many carbon atoms as there are hydroxyl groups. Thus, the simplest di-hydroxy compound is the di-hydroxy ethane, glycol, and similarly, the simplest tri-hydroxy compound is the tri-hydroxy propane, or glycerol, as above. Considering, now, those poly-hydroxy substitution products 

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From the higher poly-hydroxy alcohols similar halogen-alcohols are obtained, which are known, also, as halogen-hydrines, e.g. ... 

Ketone Alcohols.—From the higher poly-hydroxy alcohols however, which contain both primary and secondary alcohol groups we obtain both aldehyde alcohols and ketone alcohols. Glycerol or propantriol thus yields the following ... 

The following triphenylmethane dyes have been employed for determination of Sc similarly to Xylenol Orange Methylthymol Blue [33], Chrome Azurol S [34,35], Chromal Blue G [36], and Eriochrome Brilliant Violet B [37]. Much higher sensitivities have been obtained in the presence of some cationic surfactants [38 0]. In the method with Chrome Azurol S and Zephiramine, the e value is 1.5-10 at 610 nm, and in the method with Eriochrome Cyanine R and CP, e = 9.2-10" at 600 nm [40]. When o-hydroxy-quinonephthalein and CP are used, the molar absorptivity is 1.1-10 at 555 nm [41], Scandium has been determined with the use of Nile Blue in a poly(vinyl alcohol) medium [42]. 

A general synthesis for all diastereomeric L-hexoses, as an example for monosaccharides that often do not occur in the chiral pool, has been worked out. The epoxidation of allylic alcohols with tertiary butyl hydroperoxide in presence of titanyl tartaric ester catalysts converts the carbon-carbon double bond stereose-lectively to a diol and is thus ideally suited for the preparation of carbohydrates. The procedure is particularly useful as a repetitive two-carbon homologiza-tion in total syntheses of higher monosaccharides and other poly hydroxy compounds. It starts with a Wittig reaction of a benzylated a-hydroxy aldehyde with (triphenylphosphoran-ylidene)acetaldehyde to produce the olefinic double bond needed for epoxidation. Reduction with sodium-borohydride... 

The addition of formaldehyde to the alcoholic hydroxy group leads to the formation of mono(poly)hemiformals of the bicyclic oxazolidine which constitutionally exhibit higher antimicrobial effectioness, as they are able to liberate more formaldehyde than the starting product. A mixture of such hemiformals which is in use as a microbicide is listed under 3.3.14. 

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