Synthesis of Substituted Enol Ethers and Their Synthetic Application

Significance

The authors describe the preparation for trisubstituted enol derivatives via tandem carbometalation-oxygenation of terminal alkynes. The enol derivatives were isolated as a single regioisomer with a high E-selectivity (E/Z > 20:1). Stereodefined enol ethers can undergo asymmetric dihydroxylation to yield optically active α-hydroxy aldehydes. Finally, α-hydroxy aldehydes were shown to undergo homologation to a terminal alkyne, reductive amination, oxidation and olefination.