Collect. Czech. Chem. Commun.
1994, 59, 2621-2631
https://doi.org/10.1135/cccc19942621
Stereoselectivity of Michael Addition to 3-Phenyl-1-(η6-o-tolyltricarbonylchromium)propenone
Ľubomír Šeboa, Ján Šragaa, Grety Rihsb and Štefan Tomaa
a Department of Organic Chemistry, Comenius University, 842 15 Bratislava, Slovak Republic
b CIBA-GEIGY Co., 4002 Basel, Switzerland
Abstract
The stereoselectivity of the Michael addition of several C-nucleophiles to 3-phenyl-1-(η6-o-tolyltricarbonylchromium)propenone has been studied. The ratio of diastereoisomers formed varied from 65 : 35 (malonodinitrile), 72 : 28 (methyl cyanoacetate) and 78 : 22 (nitromethane) and to 90 : 10 (dimethyl malonate). The ratio of diastereoisomers 63 : 37 was found even when addition of dimethyl malonate was carried out at 75 °C in methanol using piperidine as the catalyst. The (S,R) or (R,S) configuration of the main pair of isomers was proved by the X-ray analysis of the dimethyl malonate adduct.
