Photodecarboxylative addition of carboxylates to phthalimides: a concise access to biologically active 3-(alkyl and aryl)methylene-1H-isoindolin-1-ones

A series of 3-(alkyl and aryl)methyleneisoindolin-1-one derivatives were synthesized in a simple two-step procedure using a recently established photodecarboxylative addition of carboxylates to phthalimides as the key-step. Subsequent acid-catalyzed dehydration and deprotection furnished the desired target compounds with high E-selectivity. The reaction sequence was applied to the synthesis of the known bioactive phenylethylene derivative, AKS-186. Different analogues, including heteroatom-containing isosteres were also synthesized using this approach.     

Thermochemistry of Binding of Lead(II) and Cadmium(II) by Saccharides in Aqueous Solution

Solution calorimetry was used to determine enthalpies and stability constants for binding of lead(II) or cadmium(II) by galacturonic acid and several monosaccharides in aqueous solution. New values for enthalpies of solution in water are reported for galacturonic acid and maltose monohydrate. The interaction of water solvent with the reactants is the largest factor in the binding process.     

Liquid exclusion-adsorption chromatography,a new technique for isocratic separation of nonionic surfactants. IV. Two-dimensional separation of fatty alcohol ethoxylates with focusing of fractions

Fatty alcohol ethoxylates can be analyzed using a combination of liquid chromatography under critical conditions as the first dimension and liquid exclusion-adsorption chromatography as the second dimension. Transfer of fractions from the first to the second dimension is achieved using the full adsorption-desorption (FAD) technique. The peaks of interest in the first dimension are trapped on a short precolumn before injecting them into the second dimension. Full adsorption is achieved by increasing the water content in the mobile phase before the FAD column. When the fractions are desorbed by switching to the mobile phase of the second dimension, they are focused and reconcentrated. In this way, a full resolution of oligomers is achieved. As both dimensions are run in isocratic mode, density and refractive index detection can be applied, which allows an accurate quantitation.     

A beta-lactone route to chiral gamma-substituted alpha-amino acids: application to the concise synthesis of (S)-alpha-azidobutyro lactone and a natural amino acid

[reaction: see text] Beta-lactones are useful synthetic intermediates allowing access to a number of functional arrays. In this report, enantiomerically pure 4-trichloromethyl-2-oxetanone is shown to be a versatile amino acid synthon leading to a variety of gamma-substituted alpha-amino acid precursors. The utility of this methodology was demonstrated by the concise synthesis of a protected homoserine equivalent, alpha-azidobutyro lactone, and a naturally occurring alpha-amino acid from the seeds of Blighia unijugata.