General one-step access to unsymmetric propargylic acetals <i>via</i> alcohol functionalization with allenyl ethers

We report a straightforward and robust protocol for synthesizing unsymmetric propargylic acetals through single-step alkoxypropargylation of aliphatic alcohols. This method employs allenyl ethers and hypervalent iodine reagents to achieve direct functionalization under mild conditions, producing 26 distinct acetals in 60-94% yields. The reaction's broad substrate compatibility accommodates diverse hydroxyl-containing molecules, offering a versatile and scalable platform for installing alkynyl moieties in complex molecular architectures.