The E1 Reaction. CH 3 CH 2 OH can cause elimination to occur by the E1 reaction. If possible, a carbocation may rearrange to a more stable one by an alkyl group shift or a hydride shift . The most common rearrangement is from a 2 to 3 ion. Rearrangement occurs more rapidly than does the loss of a proton from a carbocation, so rearrangement products usually predominate .
Reaction is favored in polar, protic solvents .
Unlike the E2 reaction, no special geometry is required. The reason for this trend is based upon the stabilities of various alkenes , with the more or most stable alkene being formed more easily and thus is the major product. Comparison of E1 and E2 Reactions From a practical standpoint, E2 reactions are useful for converting alkyl halides into alkenes, even when a mixture of alkenes is formed. E2 reactions can be carried out on any class of alkyl halide. E1 reactions are considerably less useful for converting alkyl halides into alkenes.