Enantioselective hydrogenation of pyrrolidine-2,3,5-triones over the Pt–cinchonidine system
摘要:
1- and I-Substituted pyrrolidine-2,3,5-triones 5, 6 and 9 have been synthesized and hydrogenated to 3-hydroxy derivatives 10-12 with 17-91% ee using a 5 wt% Pt/Al2O3 catalyst in the presence of small amounts of cinchonidine. The influence of substituents on the enantioselectivity is discussed. (C) 1999 Elsevier Science Ltd. All rights reserved.
Dihydro-4,4-dimethyl-2,3-furandione (4e) was synthesized from diethyl oxalate, methylpropanal (1a) and formaldehyde in the presence of sodium methoxide. In a similar manner, analogs of dihydro-2,3-furandione 4 were prepared using other aldehydes.
Silylation-Based Kinetic Resolution of α-Hydroxy Lactones and Lactams
作者:Robert W. Clark、T. Maxwell Deaton、Yan Zhang、Maggie I. Moore、Sheryl L. Wiskur
DOI:10.1021/ol402982w
日期:2013.12.20
A silylation-based kinetic resolution has been developed for alpha-hydroxy lactones and lactams employing the chiral isothiourea catalyst (-)-benzotetramisole and triphenylsilyl chloride as the silyl source. The system is more selective for lactones than lactams, and selectivity factors up to 100 can be achieved utilizing commercially available reagents.
Wieland; Maul, Biochemische Zeitschrift, 1954, vol. 326, p. 18,19, 22
作者:Wieland、Maul
DOI:——
日期:——
Wieland; Maul, Biochemische Zeitschrift, 1955, vol. 326, p. 18,19, 22
作者:Wieland、Maul
DOI:——
日期:——
Stereoselective reduction of diketones by a novel carbonyl reductase from Candida parapsilosis