Inverse-electron demand [(pi)2+(sigma)2+(sigma)2] cycloaddition reaction of dimethyl oxaquadricyclane-2,3-dicarboxylate with cyclooctyne

A first example of an inverse-electron demand [(pi)2 + (sigma)2 + (sigma)2] cycloaddition reaction of dimethyl oxaquadricyclane- 2,3 -dicarboxylate wa s reported: cyclooctyne underwent cycloaddition with dimethyl oxaquadricycl ane-2,3-dicarboxylate to afford the corresponding adducts one of whose stru cture was confirmed by a single crystal X-ray analysis.