Intramolecularcarbolithiation of 3-lithioxy-5-hexenyllithiums was studied. Unlike the case of 5-hexenyllithium, the cyclization of 3-lithioxy-5-hexenyllithium was very sluggish. Acceleration was observed when lithium chloride was added, suggesting that intramolecular lithioxy coordination would hinder the cyclization. Introduction of a silyl or thiophenyl group at the olefin terminus caused smooth