Organocatalytic Asymmetric Peroxidation of γ,δ-Unsaturated β-Keto Esters—A Novel Route to Chiral Cycloperoxides
作者:Mary C. Hennessy、Hirenkumar Gandhi、Timothy P. O’Sullivan
DOI:10.3390/molecules28114317
日期:——
A methodology for the asymmetric peroxidation of γ,δ-unsaturated β-ketoesters is presented. Using a cinchona-derived organocatalyst, the target δ-peroxy-β-keto esters were obtained in high enantiomeric ratios of up to 95:5. Additionally, these δ-peroxy esters can be readily reduced to chiral δ-hydroxy-β-keto esters without impacting the β-ketoester functionality. Importantly, this chemistry opens
‘One-pot’ organocatalyzed enantioselective synthesis of highly functionalized 3,4,5,6-tetrasubstituted dihydropyrans by sequential Knoevenagel condensation/Michael addition and hemiacetalization
作者:Ajay R. Tilekar、Arun R. Jagdale、Gagan Kukreja、G. Gautham Shenoy、Neelima Sinha
DOI:10.1016/j.tetasy.2016.10.014
日期:2017.1
An organocatalytic 'one-pot' synthesis of highly functionalized 3,4,5,6-tetrasubstituted dihydropyrans has been developed. Excellent enantio- and diastereo selectivity with good yields are some of the salient features of this methodology. This reaction takes advantage of proline based catalysts and follows stepwise sequential transformations including Knoevenagel condensation-Michael addition-hemiacetalization towards the synthesis of complex dihydropyranol framework. (C) 2016 Elsevier Ltd. All rights reserved.
Anionic activation of stabilized ylides. A highly Z-stereoselective wittig reaction of (3-ethoxycarbonyl-2-oxopropylidene)triphenyl-phosphorane with aliphatic aldehydes
作者:K. Michał Pietrusiewicz、Jarosław Monkiewicz
DOI:10.1016/s0040-4039(00)84088-5
日期:1986.1
PIETRUSIEWICZ, K. M.;MONKIEWICZ, J., TETRAHEDRON LETT., 1986, 27, N 6, 739-742