2003 Ring closure reactions

Ring closure reactionsO 0130 Preparation of Homoallylic Alcohols by Nickel-Catalyzed Cyclizations of Allenyl

Aldehydes. — The nickel-catalyzed cyclization of allenyl aldehydes (I) and (VI) with organozinc reagents provides an efficient access to homoallylic alcohols. Commercial-ly available as well as in situ generated organozinc reagents can be used. All the reac-tions proceed with excellent cis-diastereoselectivity. In the case of 1,3-substituted al-lenes (VI), Z-homoallylic alcohols are predominantly obtained, the Z/E-ratio depend-ing on the terminal substituent. — (MONTGOMERY*, J.; SONG, M.; Org. Lett. 4 (2002) 23, 4009-4011; Dep. Chem., Wayne State Univ., Detroit, MI 48202, USA; Eng.) — Mischke

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