A reaction of 1,3-diphenylisobenzofuran with N-arylitaconimides gives the [4+2] cycloaddition products with the 11′-oxaspiro[pyrrolidine-3,9′-tricyclo[6.2.1.0 2,7 ]undeca-2′,4′,6′-triene-2,5-dione] skeleton as a single diastereomer.
                                    1,3-二苯基异苯并呋喃与N-芳基衣康
酰亚胺的反应得到单一的非对映异构体的[4+2]环加成产物,其骨架为11′-氧杂螺[
吡咯烷-3,9′-
三环[6.2.1.0 2,7]十一碳-2′,4′,6′-
三烯-2,5-二酮]。