A Macrocyclization of (2R)-2-(N,N-Ditosylimido)-3-butenyl methyl malonate by Using Palladium Catalyst

Abstract

Upon Pd(0)-catalyzed coupling reaction of (2R)-2-(N,N-ditosylimido)-3-butenyl methyl malonate (4) which was selected for the total synthesis of A-factor, (3R)-2-(6-methylheptanoyl)-3-hydroxy methyl-4-buttinolide (1), an unexpected 14-membered cyclic compound, bis(2-methoxycabonyl-(4E)-hexenolide) (15) was obtained. The structure of this compound was conformed by X-ray crystallography. This result implies that this method can be applied the synthesis of various size of symmetrical macrocyclic compounds.