Lewis acid-catalyzed three-component condensation reactions of aldehydes, alkoxysilanes, and propargylsilane: synthesis of alpha-allenyl ethers

For simultaneous construction of a polyether backbone and the allenyl side chains, Lewis acid-catalyzed three-component condensation reactions of alde hydes, alkoxytrimethylsilanes, and 1-trimethylsilyl-2-butyne were studied. The reaction of these three compounds took place in the presence of a catal ytic amount of TrClO4 at -78 degreesC to yield the corresponding alpha -all enyl ethers in good yields. This reaction was also applied to the synthesis of a polyether having allenyl side chains. (C) 2001 Elsevier Science Ltd. All rights reserved.