Efficient preparation of vinylcyclopropane by S(N') cyclization of the organolithium derived from (E)5-iodo-1-methoxy-2-pentene

Article abstract of DOI:10.1016/S0040-4039(97)01423-8

(5-Methoxy-E-3-pentenyl)lithium (1), which may be prepared in virtually quantitative yield from the corresponding iodide by low-temperature lithium-iodine exchange, cyclizes with expulsion of the allylic methoxy on warming in the presence of TMEDA to afford vinylcyclopropane in 88% yield.