Stereoselective Construction of Cisoidal Bisspiroacetal Frameworks through Magnesium Coordination of the Bilateral Acetal Oxygen Atoms

Abstract

The cisoid-selective construction of at ricyclic bisspiroacetal framework was demonstrated using MgBr 2 as a cisoid stabilizer through chelation of the oxygen atoms of lateral acetal rings in the cisoid configuration. The method was also successfully applied to substrates with different ring sizes and substituents. Thus, this method serves as a usefuls ynthetic strategy for the total synthesis of bisspiroacetal-containing naturalproducts.