206365-22-2Relevant academic research and scientific papers
1,2-Asymmetric induction in the radical addition of organotin hydrides to (-)-menthyl(E)-2,3-disubstituted propenoates
Mandolesi,Koll,Chopa,Podesta
, p. 151 - 159 (2007/10/03)
The results obtained in the free radical hydrostannation of (-)-menthyl(E)-2,3-diphenylpropenoate (1) with tri-n-butyl- and triphenyltin hydride, and of (-)-menthyl(E)-2-phenyl-2-butenoate (7) with trimethyltin hydride are reported. The absolute configuration of the new organotin adducts was determined by combining 1H- and 13C-NMR data with chemical correlation. The additions took place in all cases following a syn stereochemistry that led to diastereomeric excesses ranging between 73 and 100%. The observed stereochemistry is explained, taking into account both the allylic strain and the hyperconjugation with β-trialkyltin substituent existing in the intermediate radicals. Full 1H-, 13C- and 19Sn-NMR data are given.
