Synthesis of Optically Active Trifluoromethylated Indolizidine Derivatives via Stereoselective Radical Cyclization
摘要:
Asymmetric Michael reaction of lithiated trifluoroacetone SAMP-hydrazone with alkylidenemalonates gave addition products stereoselectively. Hydrolyzed enantiomerically pure ketoacids were cyclized to dihydropyridinones. N-lodopropylation followed by radical cyclization gave optically active trifluoromethylated indolizidinones stereoselectively.
Asymmetric Michael reaction of lithiated trifluoroacetone SAMP-hydrazone with alkylidenemalonates gave addition products stereoselectively. Hydrolyzed enantiomerically pure ketoacids were cyclized to dihydropyridinones. N-lodopropylation followed by radical cyclization gave optically active trifluoromethylated indolizidinones stereoselectively.
.beta.-Substituted .beta.-phenylpropionyl chymotrypsins. Structural and stereochemical features in stable acyl enzymes
作者:Peter E. Reed、John A. Katzenellenbogen
DOI:10.1021/jm00107a041
日期:1991.3
to form stable acyl enzymes with alpha-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