ALLYLIC, BENZYLIC AND α-CARBONYL

 

CH protons that are allylic, benzylic or alpha to a carbonyl group are typically found in the 1.5 - 2.5 PPM range

If a group is in between two double bonds, or two carbonyl groups, etc., the chemical shift is cumulative and the protons will be found further upfield (i.e., higher PPM)