摘要:
The invention relates to optically active homo- and copolymers made from optically active (meth)acrylamides, the polymers being immobilized on silica gel, a process for their preparation, and their use as adsorbents, in particular as the stationary phase for chromatographic racemate resolution.
摘要:
The invention relates to optically active homo- and copolymers made from optically active (meth)acrylamides, the polymers being immobilized on silica gel, a process for their preparation, and their use as adsorbents, in particular as the stationary phase for chromatographic racemate resolution.
摘要:
In the chromatographic separation of a mixture of antipodes of optically active chemicals by passing a solution of such mixture over an optically active adsorbent to effect adsorption, and then eluting the adsorbed material, the improvement which comprises employing as the adsorbent particles of an optically active and cross-linked polymer containing the repeating structural unit ##STR1## in which R.sup.1 represents hydrogen or methyl, andR.sup.2 represents one of the stereoisomers of the eight possible stereoisomeric forms of each of the optically active radicals of the formulae ##STR2## Improved separation results. The pure monomers are also new.
摘要:
Diastereomers can be separated with good industrial success with the aid of extractive distillation. The separation process is characterized in that an auxiliary which changes the partial pressure of the various diastereomers to be separated to a different degree and thus allows easier separation of the diastereomers by distillation is added during the distillation. Using the present process diastereomic cis/trans-permetric acid methyl esters and mixtures of menthol and isomenthol can be separated with isolation of 99% pure product.
摘要:
What are disclosed are a multi-step synthesis for the preparation of 9(11)-dehydroestrone 3-methyl ether from 2-methyl,4-methoxy benzaldehyde; 1-(4-methoxy-2-methyl-(phenyl)-3-(1-methyl-2-oxo-5-t-vinyl-cyclopent-r-yl)-propane-1-one, an intermediate in said synthesis; and a method for the preparation of 3-vinylcyclopentanone from 2-vinylcyclopropane-1,1-dicarboxylic acid.