Chiral Template Mediated Diastereoselective Intramolecular Diels−Alder Reaction Using Furan as a Diene. Toward the Synthesis of Enantiopure Trisubstituted Tetrahydroepoxyisoindolones

Chiral precursors to the intramolecular Diels−Alder reaction using furan as a diene (IMDAF) have been prepared by diastereoselective addition of furyllithium to imines attached to perhydro-1,3-benzoxazines derived from (−)-8-aminomenthol. The acylation of the furylamines with α,β-unsaturated acyl chlorides and subsequent IMDAF reaction under thermal conditions provided the corresponding cycloadducts as single diastereoisomers. The hydrolytic elimination of the chiral template yielded enantiopure perhydroepoxyisoindolones with up to five stereocenters.