1H NMR Chemical Shifts and Coupling Constants of Some 3-Monosubstituted 2-Methylpropenes

Abstract

1H NMR chemical shifts and proton–proton coupling constants for some 3-substituted 2-methylpropenes [YCH2C(Me)CH2, Y=H, Cl, Br, I, OH, OMe, OEt, SH, SMe, SEt, NMe2 and NEt2] are reported. Resonances of the olefinic protons were assigned through lanthanide-induced shifts. Chemical shifts of the olefinic protons (HA and HB) showed a dependence on the substituent at C-3 of the allylic fragment. Long-range allylic coupling constants (4Jcisoid for HA and CH2 and HB and Me; 4Jtransoid for HB and CH2 and HA and Me) were determined by spectral expansion and simulation. © 1997 by John Wiley & Sons, Ltd.