REACTIONS OF DIAZOALKANES WITH UNSATURATED COMPOUNDS. 7. CATALYTICAL CYCLOPROPANATION OF 1-ALKOXY-, 1-ACETOXY-, AND 1-(TRIMETHYLSILYLOXY)BUTA-1,3-DIENES WITH DIAZOMETHANE

Article abstract of DOI:10.1007/BF00962436

Cyclopropanation of 1-butadienyl ethers or esters with diazomethane proceeds selectively in the presence of (PhCN)2PdCl2, as opposed to CuCl, at the less polar terminal double bond in these dienes when the molar proportions of reactants and catalysts are 1:(1.3-2):(0.002-0.005) to give the 2-cyclopropylvinyl ethers or esters in yields of 80-85percent.