Trimethyl Orthoacetate and Ethylene Glycol Mono-Vinyl Ether as Enolate Surrogates in Enantioselective Iridium-Catalyzed Allylation

Trimethyl orthoacetate and ethylene glycol mono-vinyl ether are employed in iridium-catalyzed enantioselective allylation reactions. The method documented enables their convenient use as surrogates for silyl ketene acetals and silyl enol ethers to prepare gamma,delta-kunsaturated esters and protected aldehydes with excellent enantioselectivity. The utility of this novel method has been demonstrated by its implementation in a formal enantioselective synthesis of the meroterpenoid (+)-conicol.