Author/Authors :
Averina، نويسنده , , Elena B. and Samoilichenko، نويسنده , , Yuri V. and Volkova، نويسنده , , Yulia A. and Grishin، نويسنده , , Yuri K. and Rybakov، نويسنده , , Victor B. and Kutateladze، نويسنده , , Andrei G. and Elyashberg، نويسنده , , Mikhail E. and Kuznetsova، نويسنده , , Tamara S. and Zefirov، نويسنده , , Nikolai S.، نويسنده ,
Abstract :
Revised regiochemistry for the heterocyclization of electrophilic alkenes with tetranitromethane (TNM) in the presence of triethylamine, providing rapid access to nitroisoxazoles, is reported. The formation of 5-nitroisoxazoles previously incorrectly assigned as 3-nitro regioisomers, has now been established unambiguously by X-ray crystallography. Empirical computations with ACD/CNMR Predictor, based both on hierarchical ordering of spherical environments (HOSE) and an algorithm of artificial neural networks (ANN), and also Density Functional Theory computations of the 13C NMR chemical shifts for the 3- versus 5-nitroisoxazoles are shown to consistently match the spectra of the experimentally observed 5-regioisomers.
Keywords :
tetranitromethane , Electrophilic alkenes , Nitroisoxazoles , X-ray crystallography , 13C NMR shift calculations
