Thermal and photochemical decompositions of 5-exo- and 5-endo-methyl-2-cyano-3,4-diazapentacyclo[6,4,0,02,6,07,11,010,12]dodec-3-ene: a lowered stereoselectivity by the steric inhibitions of the rotation of an intermediate nitrogen-containing diradical

Abstract

Considerably lower stereoselective formation of the single inversion product was observed for 5-endo-methyl 2-cyano-3,4-diazapentacyclo[6,4,0,0^2,6,0^7,11,0^7,11,0^10,12]dodec-3-ene [endo-(3)] compared to its exo-isomer in their thermal and direct photodecompositions.