Friedel-Crafts Alkylation of Alkenes: Ethylaluminum Sesquichloride Induced Alkylations with Alkyl Chloroformates.

The formal addition of propane to nonactivated double bonds can be achieved with isopropyl chloroformate (2) in the presence of Et(3)Al(2)Cl(3). Thus, a 1:1 mixture of 10-isopropyloctadecanoic acid (3) and the 9-regioisomer is formed from oleic acid (1). The reaction may also be carried out with 1-alkenes by the addition of triethylsilane as a hydride donor.