Since the molecule contains an asymmetric carbon atom, the acid exists in three forms, one being an inactive "racemic" mixture, and the other two being optically active forms. The inactive variety is known as paramandelic acid.
If the configuration of d-saccharic acid were given by either 6 or To, bearing in mind the relation of mannose to glucose, it would then be necessary to represent d-mannosaccharic acid by either 7 or 8 - as the forms 6 and Io pass into 7 and 8 on changing the sign of a terminal group; but this cannot be done as mannosaccharic acid is optically active.
Hence it follows that the " optical " formulae of the acids derived from two pentoses having the configuration given above will be C02H - 0 - C02H CO 2 H + 0 - C02H, and that consequently only one of the acids will be optically active.
If the nitrogen atom in the quaternary ammonium salts be in combination with four different groups, then the molecule is asymmetrical, and the salt can be resolved into optically active enantiamorphous isomerides.
The corresponding iodides are obtained by the addition of potassium iodide to solutions of the sulphonates, and are optically active antipodes.
VALERIC ACID, or [[Valerianic Acid, C4h9 C02h]], an organic acid belonging to the fatty acid series, which exists in four isomeric forms, one of which contains an asymmetric carbon atom and consequently occurs in two optically active modifications and one optically inactive modification.
CH 2 CO 2 H, and optically active methylethylacetic acid, (CH 3) (C 2 H 5)CH CO 2 H, which occur free or as esters in the vegetable and animal kingdoms, chiefly in the roots of Angelica archangelica and Valeriana officinalis.
It is optically active - a fact taken account of in J.
W.) hydrogen result; Micrococcus acidi-paralactici, on the other hand, ferments such solutions to optically active paralactic acid.
It crystallizes in colourless prisms and is optically active.
It occurs in two optically active forms, namely, as laevo-asparagine and dextro-asparagine.
Nearly all molecules synthesized by living organisms are optically active.
It is an optically active liquid which boils at 168-169Ã‚° C. Homologues of menthone may be obtained from the ketone by successive treatment with sodium amide and alkyl halides (A.
The trans-acid has been resolved by means of its strychnine salts into two optically active isomerides, both of which readily pass to 2' dihydrophthalic acid (A.
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