New systems for classical nitrosohalogenation of alkenes 1. Reactions of alkenes with ethyl nitrite in the presence of phosphorus halides and thionyl chloride

Studies of nitrosation of norbornene and norbornadiene derivatives and dimethyl tricyclo[4.2.2.02,5]deca-3,7-diene-9,10-cis-endo-dicarboxylate demonstrated that nitrosation of alkenes with EtONO-PHal3, EtONO-POHal3 (Hal = Cl or Br), and EtONO-SOCl2 systems can afford nitroso halides in high yields without the formation of by-products (ketones and oximes). The reactions with 5-substituted norbornenes are nonregioselective. The trans dimer of endo-5-trifluoromethyl-cis-exo-2-chloro-3-nitrosobicyclo[2.2.1]heptane was studied by X-ray diffraction.