The reaction of alkynylstannanes with 1-phenyl-3,4-1-oxide confirms the functionalisation at the α-position and the relief of ring strain taking place upon insertion of oxygen dimethylphosphole at 150 °C affords the corresponding 2stannyl-1-phosphanorbornadienes (2a,b), in fair yield. into the P-CH 2 bond of the norbornadiene. The 2-stannyl-1phosphanorbornadiene 1-oxides (3a,b) readily undergo tin Ǟ Oxidation under mild conditions affords the corresponding phosphane oxides (3a,b), whereas more drastic conditions iodine exchange. The resulting 2-iodo derivatives (6a,b) can be cross-coupled with 2-furyl-, 2-thienyl-, 2-pyrrolyl-, (H 2 O 2 , 15% in toluene at 80 °C) induce the oxidative cleavage of the P-CH 2 bond of the bridge to give a bicyclic phenylethynyl-, and vinyl-tributylstannanes to give the corresponding 2-functional 1-phosphanorbornadiene 1-phosphinate such as 4. Treatement of 4 by iodine leads to a tin Ǟ iodine exchange. The X-ray crystal structure analysis oxides in excellent yields (80-95%) of the resulting 1-phospha-2-oxabicyclo[2.2.2]octa-5,7-diene