Transition-metal-catalyzed reaction of diazocompounds, efficient synthesis of functionalized ethers by carbene insertion into the hydroxylic bond of alcohols

An Efficient catalytic synthesis of unsaturated ethers by carbene insertion (with diazoesters as carbene precursors) into the OH bond of unsaturated alcohols is reported. The regioselectivity for the OH insertion is high. However, depending on the catalyst counter-ions and the diazoester alkoxy group, addition to the unsaturated centre can be promoted to some extent, yielding then cyclopropyl and cyclopropenyl carbinols. The mechanistic aspects of the reactions are discussed. © 1982.