Page 1. Tccrahcdron L.ztmrs. Vo131, No.28, p~40814084.15'90 Priimd in Great Britain ... termediate formation, the definite assignments of 31 P NMR shifts prior to and after ... b) WJ Stec, G, Zon, KA Gallo, RA Byrd, Tetrahedron Lett., 26, 2191 (1985). ...