-CYCLOADDITION OF SINGLET OXYGEN TO CONJUGATED ACYCLIC HEXADIENES : EVIDENCE OF SINGLET OXYGEN INDUCED cistrans-ISOMERIZATION

Article abstract of DOI:10.1016/S0040-4039(00)86254-1

Addition of singlet oxygen to trans,trans-2,4-hexadiene (1) occurs stereospecifically to give endoperoxide 2.With cis,trans-2,4-hexadiene (4), however, a mixture of diastereomeric endoperoxides, 2 + 5, is observed.Evidence of a singlet oxygen - induced cis<*>trans - isomerization is gained by competitive Diels-Alder reaction of 4 with singlet oxygen/diethyl diazenedicarboxylate.