Abstract: Nitroolefins are versatile intermediates in the synthesis of complex natural products because of their various functional group transformations. They can proceed Michael type additions, and Diels-Alder cyclic reactions. Furthermore, the--NO₂ group can be converted to carbonyl group by reductive Nef reaction. Their synthetic potential should be greatly enhanced if they contain quaternary carbon centers. Here, we wish to describe stereoselective nitroolefination of α-substituted carbonyl compounds via addition-elimination on the basis of our previous research. The E stereochemistry of double bond was determined by ¹H NMR data (chemical shift, the coupling constant). Studies on effects of different metal ions on reaction temperature, time and yields showed Zn²⁺ enhanced reactivity. A rational process of addition-elimination was proposed to elucidate the reaction mechanism.

Key words: Nitroolefinic lactone, Quaternary carbon center, Stereoselective synthesis