摘要:
Mixtures of enantiomeric D,L-threo 2-amino-3-hydroxy-3-phenylpropionic acids can be stereoisomerically enriched by contacting the mixture with a D-threonine aldolase. In a typical embodiment, D- and L-threo 2-amino-3-hydroxy-3-(4-methylsulfonylphenyl)propionic acid is treated with D-threonine aldolase to produce L-threo 2-amino-3-hydroxy-3-(4-methylsulfonylphenyl)propionic acid with a high ee. The benzaldehyde and amino acid formed from the D-threo isomer can be recycled.
摘要:
The invention relates to certain substituted phenoxypropionaldehyde derivatives, formulations of said derivatives and the use thereof for preemergence or postemergence control of noxious plants, i.e., weeds.
摘要:
The (R,R)-diastereoisomer of oxazolidin-2-ones, which are chemical intermediates for the preparation therapeutic agents useful in the treatment of diabetes and hyperglycemia, are prepared substantially free of isomeric forms through reduction of an acid addition salt of an (R)-N-protected-N-phenylcarboxymethyl-1-phenylprop-2-ylamine to form a secondary alcohol of predominantly the (R,R) chiral form in preference to others, removal of the protecting group to form a secondary amine, and allowing the secondary amine to react with a source of carbonyl groups. A typical embodiment involves the preparation of (R,R)-3-[1-(3,4-dimethoxyphenyl)prop-2-yl]-5-(3-chlorophenyl)oxazolidin-2-one in which both the chemical purity and optical purity are in excess of 99%.
摘要:
Hydroxychroman-2-carboxylic acid esters can be resolved by enantiospecific hydrolysis by the use of liver enzymes, particularly solvent treated (acetone) enzymes. Liver enzymes from calf, cat, dog, eel, goat, lungfish, mouse, rat and seal have been found to be enantiospecific.
摘要:
The invention relates to certain substituted phenoxypropionaldehyde derivatives, formulations of said derivatives and the use thereof for preemergence or postemergence control of noxious plants, i.e., weeds.
摘要:
This invention relates to certain 3-isoxazolyl-2-imidazolidinone derivatives, namely 3-[5- or 3-substituted -3- or -5-isoxazolyl]-1-,4- or 5-substituted-2-imidazolidinones and the use thereof for preemergence or post-emergence control of noxious plants, i.e., weeds.