Gl. Kad et al., Regioselective alpha-alkylation of silyl enolates using a mild catalyst- ZnCl2 doped on acidic alumina, SYN COMMUN, 29(19), 1999, pp. 3439-3442
ZnCl2 doped acidic alumina used as a solid support acts as a better Lewis a
cid in the S(N)1 reaction of trimethyl silyl enol ethers with 3(0),allylic
and benzylic halides to yield exclusively the substituted product in excell
ent yields, This method has been employed for the synthesis of monocyclic s
esquitepene hydrocarbon, (+/-)-beta-bisabolene and a monoterpene, 2,6-dimet
hyl-7-octen-4-one.