ABSTRACT
The parallel kinetic resolution of racemic 2-aryl-2-deuterio-propionic and butanoic acids using an equimolar combination of quasi-enantiomeric oxazolidin-2-ones is discussed. The levels of diastereoselectivity were high leading to enantiomerically pure D-labeled products in good yield.
Subject(s)
Biocatalysis , Butyrates/chemistry , Lactation/metabolism , Oxadiazoles/chemistry , Oxazolidinones/chemical synthesis , Propionates/chemistry , Stereoisomerism , Animals , Antifungal Agents/chemistry , Chromatography, High Pressure Liquid , Crystallography, X-Ray , Equipment Design , Female , Flow Injection Analysis , Hydrogen-Ion Concentration , Kinetics , Larva/drug effects , Microbial Sensitivity Tests , Models, Molecular , Molecular Structure , Oxazolidinones/chemistry , Structure-Activity Relationship , Sweetening Agents/chemistryABSTRACT
A series of enantiomerically pure [D,(13)C]-labeled isotopomeric 2-phenylpropionic acids were efficiently synthesized using a diastereoselective alkylation and kinetic resolution strategy.
ABSTRACT
Parallel kinetic resolution of Evans' phenylglycine derived oxazolidinone using an equimolar combination of quasi-enantiomeric active esters (derived from [D,13C]-labeled 2-phenylpropionic acid) was achieved. The levels of stereocontrol were high, leading to products with predictable configurations.
ABSTRACT
Mutual separation of an equimolar mixture of quasi-enantiomeric [D,13C]-labeled isotopomers of pentafluorophenyl 2-phenylpropionate can be achieved efficiently by use of two quasi-enantiomeric Evans' oxazolidinones. The levels of stereocontrol were high, leading to products with predictable configurations.
ABSTRACT
Results are reported on the efficiency of polyfluorooctanol as a perfluorous auxiliary component in the aldol reaction between the enolate derived from polyfluorooctyl acetate and 2-fluorobenzaldehyde. Reduction of the corresponding polyfluoro beta-hydroxy ester with Super Hydride gave the required 1,3-diol in good yield.
Subject(s)
Aldehydes/chemistry , Hydrocarbons, Fluorinated/chemistry , Catalysis , Models, Chemical , Molecular Structure , StereoisomerismABSTRACT
The title compound, bis(2-isopropyl-5-methylcyclohex-1-yl) malonate, C(23)H(40)O(4), crystallizes in the monoclinic space group P2(1). In the crystal, the molecule is not C(2) symmetric.
ABSTRACT
A series of substituted dimenthyl malonate derivatives were efficiently synthesized from dimenthyl malonate using a deprotonation and alkylation strategy. The elucidation of the structure of these derivatives were determined by a combination of X-ray crystallography, NMR and IR spectroscopy.
ABSTRACT
Kharasch and Sosnovsky reported the allylic oxidation of alkenes to give racemic allylic benzoates. This could be achieved efficiently using a tert-butyl perester as the oxidant, in the presence of a copper or cobalt salt. The use of C(2)-symmetric bis(oxazoline) ligands in the presence of copper(I) triflate with cyclic olefinic substrates gave the first synthetically useful asymmetric variant. The enantioselective control was good (up to 84 % ee) although yields were variable. In all cases the facial preference of the newly formed C-O bond was the same giving an S configuration at the allylic stereocenter. Lower stereocontrol was observed for large-ring alkenes and substantially reduced enantioselectivities were found with open-chain alkenes. This reaction has been further screened using a variety bis(oxazoline) and proline-derived ligands, which give a direct correlation between the chirality of the ligand and the enantioselectivity obtained. Individual substrates were found to be extremely sensitive to both the ligand structure and copper salt used as well as the presence of additives such as zinc, hydrazine, and molecular sieves.
