6049-47-4Relevant academic research and scientific papers
DBU-Catalyzed Ring-Opening and Retro-Claisen Fragmentation of Dihydropyranones
Axelsson, Anton,Hammarvid, Emmelie,Rahm, Martin,Sundén, Henrik
, p. 5436 - 5444 (2020/08/26)
We present a general protocol for the formal Michael addition of acetone to α,β-unsaturated esters and amides, a transformation difficult to perform using current methods. The protocol comprises of an amidine catalyzed relay ring-opening and fragmentation
β-substituted β-phenylpropionyl chymotrypsins. Structural and stereochemical features in stable acyl enzymes
Reed,Katzenellenbogen
, p. 1162 - 1176 (2007/10/02)
In order to develop effective alternate substrate inhibitors for serine proteases, we have prepared a series of β-substituted β-phenylpropionic acid esters related to some systems known to form stable acyl enzymes with α-chymotrypsin. Some of these compounds were prepared in enantiomerically pure form by asymmetric synthesis. Acyl enzyme species were generated from chymotrypsin by reaction with the active esters, and the progress of deacylation was monitored by the proflavin displacement assay. In some cases, it was possible to distinguish two different deacylation rates that correspond to the two enantiomers. β-Phenylpropionic acyl enzymes with β-substituents that are nonpolar were not especially stable, but a number of the polar derivatives and particularly the acylamino derivatives showed slow rates of deacylation (k(d) less than 0.005 min-1), with three systems showing deacylation enantioselectivities in the range of 500-1500. These results are consistent with a model in which additional stabilization of the acyl enzyme and enantioselectivity in the deacylation process derives from an additional hydrogen bond between the acyl enzyme species (as an acceptor) and the enzyme (as a donor). A number of active site residues that might be involved in this hydrogen bond are discussed.
Process for preparing highly substituted phenyls
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, (2008/06/13)
A process is described in which a lactone STR1 is reacted with an alkylester X1 --CH2 and an oxidizing or dehydrogenating agent to form the phenol ester STR2
USE OF 1,3-DIOXIN-4-ONES AND THEIR RELATED COMPOUNDS IN SYNTHESIS. 27. NOVEL ASYMMETRIC HETERO-DIELS-ALDER REACTION USING CHIRAL SPIRO 5-METHYLENE-1,3-DIOXANE-4,6-DIONES HAVING 1-MENTHONE AT THE 2-POSITION
Sato, Masayuki,Kano, Kazuya,Kitazawa, Noritaka,Hisamichi, Hiroyuki,Kaneko, Chikara
, p. 1229 - 1232 (2007/10/02)
Diastereofacially selective hetero-Diels-Alder reaction of spiro (E or Z)-5-arylidene-1,3-dioxane-4,6-diones and 2-methoxypropene was studied.The dihydropyrans thus obtained were converted to optically active β-arylated δ-oxohexanoic acids.The diastereofa
Resolution and Determination of the Absolute Stereochemistry of α- and β-Aryl-Substituted γ-Methylenevalerolactones, Alternate Substrate Inhibitors for Serine Proteases
Baek, Du-Jong,Daniels, Scott B.,Reed, Peter E.,Katzenellenbogen, John A.
, p. 3963 - 3972 (2007/10/02)
To study the enantioselectivity of alternate substrate inhibition of chymotrypsin by chiral α- and β-arylsubstituted enol lactones, we have prepared four of these lactones in homochiral form: 3-phenyl-6-methylenetetrahydro-2-pyranone (αPh6H, IIa), 3-(1-na
Enol Lactone Inhibitors of Serine Proteases. The Effect of Regiochemistry on the Inactivation Behavior of Phenyl-Substituted (Halomethylene)tetra- and -dihydrofuranones and (Halomethylene)tetrahydropyranones toward α-Chymotrypsin: Stable Acyl Enzyme Inter
Sofia, Michael J.,Katzenellenbogen, John A.
, p. 230 - 238 (2007/10/02)
We have found that α-aryl-substituted halo enol lactones (I and II) are effective mechanism-based inactivators for chymotrypsin.In this study, we have investigated, for comparative purposes, halo enol lactones with aryl functions situated β and γ to the l
