AN EFFICIENT METHOD FOR THE STEREOSELECTIVE SYNTHESIS OF TRICYCLIC COMPOUNDS—THE INTRAMOLECULAR DIELS–ALDER REACTION OF CYCLIC α,β-UNSATURATED CARBOXAMIDES—
An efficient method for the stereoselectivesynthesis of tricyclic compounds was studied by the intramolecularDiels–Alderreaction utilizing the internal coordination of the magnesium salt. The magnesium salts of N-(2,4-alkadienyl)-N-(2-hydroxyphenyl) cyclopent-1-enecarboxamides afford predominantly trans-fused cycloadducts via exo-mode of cyclization.