Absolute Configurational Assignment of Acyclic Hydroxy Carboxylic Acids: A New Strategy in Exciton-Coupled Circular Dichroism
A new strategy in exciton-coupled circular dichroism (ECCD) is described for the configurational assignment of α-hydroxy carboxylic acids.Using 9-anthryldiazomethane (4), carboxyl groups can be selectively derivatized with a chromophore suitable for exciton coupling.In combination with the 2-naphthoate chromophore linked to the α-hydroxy group, the absolute stereochemistry of α-hydroxy carboxylic acids can be easily deduced from a single CD measurement.The usefulness of the new method is demonstrated with a series of α-hydroxy acids with different side chains.The developed microscale method is also useful for chiral amino acids and natural products containing carboxylic groups or similar strucutral units.
Javed, Muhammad I.,Brewer, Matthias,Ellman, Jonathan A.,Tsai, Andy S.
p. 189 - 195
(2017/09/15)
Diazo preparation via dehydrogenation of hydrazones with "activated" DMSO
We report that "activated" dimethyl sulfoxide efficiently dehydrogenates hydrazones to the respective diazo species at -78°C. Under optimized conditions, triethylamine hydrochloride is removed quantitatively by vacuum filtration to provide solutions of diazo compounds. Stable diazo species can be isolated in high yield, or alternatively, the direct treatment of these solutions with carboxylic acids provides esters.
Javed, Muhammad I.,Brewer, Matthias
p. 1789 - 1792
(2008/02/02)
More Articles about upstream products of 10401-59-9