Steric and electronic effects on the photochemical reactivity of oxime acetates of β,γ-unsaturated aldehydes

Synthetic Aspects of the Di-π-methane Rearrangement

“…This was the first example of an ADPM rearrangement in an acyclic C−N double-bond-stable derivative. The ADPM reaction has been extended to a series of acyclic and cyclic β,γ-unsaturated oxime acetates 210a−h , − 212 , 214 , 216 , 218 , and 220a,b . All of them undergo the ADPM rearrangement to the corresponding cyclopropyl oxime acetates 211a−h , 213 , 215 , 217 , 219 , 221a,b , respectively.…”

“…Oxime acetates without substituents at the γ-position that will insure sufficient stabilization of the 1,4-cyclopropyl biradical intermediates do not undergo the ADPM rearrangement. This is the case of oxime acetates 224 that give cis/trans isomerization 157b,158 and compound 225 ,157b which is unreactive. Phenyl substitution at position 4 of the 1-aza-1,4-diene system promotes a different reaction.…”

Synthesis of 1H-isoindoles by a novel rearrangement of some isoquinolin-4(1H)-ones

“…One of the tests for the involvement of an electron transfer mechanism involved the protonation of the molecules 1 by perchloric acid. Under these conditions irradiation brought about a new reaction in which the 2-aza-1,3-dienes 1 were converted rapidly and efficiently into a series of isoquinolinones 3 by a photochemical Mannich cy~lization.~ Usually the isoquinolinones obtained were aryl substituted and stable. However, in one example an isoquinolinone 4 was prepared with a 2-methyl substituent.…”

Novel photochemical behaviour of the oximes and hydrazones of β,γ-unsaturated carbonyl compounds

“…2,2-Dimethyl-4-phenylbut-3-enal oxime 3d, 7 2,2-dimethyl-4,4-diphenylbut-3-enal oxime 3e, 1 2,2-dimethyl-4,4-diphenylbut-3-enal benzoylhydrazone 8c 14 and 2,2-dimethyl-4,4-diphenylbut-3-enal acetylhydrazone 8d 14 were prepared as previously described.…”