Intramolecular cyclization reactions of YCH2CH=CHCH(2)XCH(2)CH=CH2 (X
= CH2, NPr, NPh; Y = PhO, MeO), which have a terminal double bond and
an allylic ether moiety, were catalyzed by zirconocene dichloride (10-
20 mol %) in the presence of n-BuMgCl. Cyclization products 2-methyl-1
-vinylcyclopentane, 4-methyl-1-propyl-3-vinylpyrrolidine, and 4-methyl
-1-phenyl-3-vinylpyrrolidine were obtained in 60-80% yields. Stoichiom
etric cyclization with Cp(2)ZrBu(2) or (C(5)H(3)Me(2))(2)ZrBu(2) at ro
om temperature gave the same products in high yields after hydrolysis.
When an excess Of CP(2)ZrBu(2) was used, the stereoisomerization of c
is product to trans isomer was observed.