Etherification of C-5- and C-8-alkenes with C-1- to C-4-alcohols

Etherification of two alkenes, 2-methyl-1-butene and 2,4,4-trimethyl-1-pent ene, was studied with seven different C-1- to C-4-alcohols. Although etheri fication was of primary interest, the isomerisation of the alkenes was the main reaction to occur. For the primary alcohols the etherification and iso merisation rates correlated well with the properties of the alcohols. Both rates increased with decreasing polarity and with increasing carbon number, acidity and Mulliken charge of the oxygen atom of the alcohol. It is diffi cult to distinguish the effect of each property separately, and probably th e differences in the reactivities are not due to any one property alone but rather the synergy of the properties affects the reactivities. The seconda ry alcohols behaved in a different way than the primary ones: the etherific ation was almost negligible. The effect of alcohol on the isomerisation of alkenes was notable even though alcohol does not directly react in the reac tion, which was concluded to be due to the stronger adsorption of the more polar alcohols which hinders the reactions of other components.