A series of five new catalysts I–V based upon the immobilization of 2-deoxyribose-5-phosphate aldolase (DERA) on multiwalledcarbonnanotubes (MWCNTs) were prepared, and their use for the formation of the C–C bond via cross-aldol condensation, under environmentalfriendly conditions, was studied. Among the various employed procedures, the direct immobilization of the enzyme through ionic exchange interactions
substituted ,-unsaturated -lactones is presented. An analysis of X-ray crystallographic data for 67 compounds demonstrated a great conformational diversity of the saturated -lactone ring. Besides, ab initio calculations (HF/6-31G*) indicated a very high conformational mobility. Thus, the lowest calculated transition state for the conversion of the half-chair, most stable, conformer of -valerolactone
Abstract Coumarin-based “turn-off” fluorescentchemosensor, 3-acetoacetyl-7-diethylaminocoumarin ( 1 ), has been synthesized and structurally characterized by IR, 1 H NMR and X-ray crystal structure analysis. The fluorescence behaviors in the presence of various metal ions were investigated in aqueousmedia. 1 Exhibits highly selective and sensitive absorbance and fluorescence sensing ability for Cu
A process for the separation of at least one isomer from a mixture of isomers of a tetrahydropyran-2-one, having at least two chiral centres, which comprises selective reaction of at least one isomer with a reagent catalysed by a hydrolase enzyme whereby at least one isomer is preferentially converted into a distinct chemical species from the other isomers so that it is susceptible of separation by an appropriate chemical or physical separation process in which the tetrahydropyranone is of Formula (1): ##STR1## wherein: Z is --H or a protecting group susceptible of reaction with the reagent under the influence of the enzyme; and Y is optionally substituted hydrocarbyl.