Synthesis of leucascandrolide A

This paper describes a convergent and stereocontrolled synthesis of leucascandrolide A, a marine natural product that exhibits potent growth inhibition of mammalian and yeast cells. The approach features a substrate-directed relay of the stereochemical information via a series of highly diastereoselective transformations. Spontaneous macrolactolization discovered during this synthetic exercise has provided an unprecedented access to this marine macrolide and demonstrates a new tactic for assembling large-ring systems based on the thermodynamic preference of hemiacetalization.