The Stereochemistry of the Addition of Two Diazoalkanephosphonates to Norbornene and Norbornadiene; Photolysis of the Adducts. An Entry into the Dimethyl Tricyclo[2.1.1.02.4]octyl Phosphonate System

Abstract

Dimethyl phenyldiazomethyl- and methyldiazomethylphosphonates were treated with norbornene and norbornadiene and the configuration of the Δ1-pyrazolines obtained (3–8) was deduced from n.m.r. by using the dihedral angular dependence relationship of vicinal 31P,1H couplings. The adducts were photolyzed under sensitized and non-sensitized conditions. The resulting cyclopropyl derivatives (9–12 and 14–17) were assigned configuration by using n.m.r. data. The results are discussed in terms of steric and electronic factors. The n.m.r. and mass spectral data are also discussed.