Ottorino De Lucchi

(2+2)-cycloaddition of triazolinediones to strained bicycloalkenes

Abstract Substituted norbornenes and dibenzobarrelene react under forced conditions with N -methyl-1,2,4-triazolin-3,5-diones to afford urazoles via (2+2)-cycloaddition.

Reaction of bicyclo[3.2.1]octadiene with 4-methyl-1,2,4-triazoline-3,5-dione: competitive dipolar and homo-cycloaddition

Abstract The nonconjugated bicyclo[3.2.1]octa-2,6-diene ( 1 ) affords with 4-methyl-1,2,4-triazolin-3,5-dione (MTAD) the homo-cycloadduct ( 2 ) product and the rearranged urazoles ( 3 ) and ( 4 ) through dipolar cycloaddition, while ene-reaction and (2+2)-cycloaddition are not observed.

Cycloaddition of 4-phenyl-1,2,4-triazoline-3,5-dione (PTAD) to bicycloalkenes via rearrangement of zwitterionic intermediates

Abstract The formation of tricyclic urazoles between PTAD and bicyclic olefins via rearrangement of the intermediary 1,4-dipoles appears to be general, including moderately strained, benzo-annulated, and functionalized substrates.

Reaction of cycloheptatrienes with sulphur dioxide: Formation of benzenealkanesulphinic acids

Abstract Cycloheptatriene, 7-methylcycloheptatriene, and 7-phenylcycloeptatriene in liquid SO 2 convert in about 3 d at 18°C to benzenemethanesulphinic acid, 1-benzeneethanesulphinic acid, and dibenzenemethanesulphinic acid respectively; benzonorcaradiene gives in 2 h the α- and β-naphtalenemethanesulphinic acids.

2.5 – Di-π-methane Photoisomerizations

The term di-π-methane rearrangement is meant to describe the photoisomerization of 1,4-dienes (i.e. two π-systems separated by a methane unit) leading to vinylcyclopropanes. The reaction can be generalized in schematic form as in equation (1). As will be discussed more specifically in the section dealing with mechanism, such a simplistic presentation is not intended as the actual reaction path, but it greatly helps in predicting the reaction products.