VINYLCYCLOPROPANATION OF NORBORNADIENE, NORBORNENE, AND DISPIROHEPTADIENE BY METHYL-ESTERS OF 1-ALKYLCYCLOPROPENE-3-CARBOXYLIC ACIDS

Methyl esters of 1-alkylcyclopropene-3-carboxylic acids (I) in the presence of CuCl·P(OPh)3cyclopropanate the intracyclic norbornene double bonds of norbornene, norbornadiene, and dispiroheptadiene to give the corresponding vinylcyclopropane adducts in yields up to 80%. 3,5-Dioxo-4-oxatricyclo[5.2.1. 02,6]dec-8-ene and 5-acetyl-7-oxabicyclo[2.2.1]hept-2-ene, which are heteroanalogs of dicyclopentadiene and norbornene, are inert relative to (I). © 1990 Plenum Publishing Corporation.