Anionic cyclizations using vinyl sulfides as acceptors

Abstract

Alkyllithium intermediate containing vinyl sulfide generated by lithiumiodine exchange of 6-iodo-1-hexenylphenyl sulfide with t-BuLi cyclizes to form 5-membered ring. $\alpha$-Alkoxylithium containing vinyl sulfide generated by transmetallation of [4-((tri-n-butylstannyl) methyl) oxy]-1-heptenylphenyl sulfide with n-BuLi cyclizes to form tetrahydrofuran ring. The formed cyclization products are quenched by various electrophiles to give functionalized cyclopentanyl or tetrahydrofuranyl derivatives in good yields. Attempts to form 6-membered rings by anionic cyclization using vinyl sulfide group as an acceptor are unsuccessful.