Mechanism of photoisomerization of optically pure trans-2,3-diphenylcyclopropane-1-carboxylic acid derivatives.
The photochemistry of optically pure isomers of alpha-methylbenzylamide of trans-2,3-diphenylcyclopropane-1-carboxylic acid has been examined in isotropic solution and within zeolites. The results suggest that these isomerize through cleavage of C2-C3 bond. The direct excitation in solution leads to non-equilibrating 1,3-singlet diradical intermediates whereas triplet sensitization results in equilibrating 1,3-triplet diradical intermediates. The direct excitation within NaY zeolite seems to result in equilibrating zwitterionic intermediates. Studies on the optically pure trans isomers allow one to understand the mechanism of chiral induction during the photoisomerization of mesocis-2,3-diphenylcyclopropane-1-carboxylic acid. The current study has clarified the nature of the excited states involved during the classic (R)-N-acetyl-1-naphthylethylamine sensitized isomerization of 1,2-diphenylcyclopropane.
Sivaguru
J
J
Department of Chemistry, Tulane University, New Orleans, LA 70118, USA.
Wada
Takehiko
T
Origane
Yumi
Y
Inoue
Yoshihisa
Y
Ramamurthy
V
V
D002264:Carboxylic Acids / Q000138:chemical synthesis / Q000737:chemistry*; D003521:Cyclopropanes / Q000138:chemical synthesis / Q000737:chemistry*; D008968:Molecular Conformation; D010777:Photochemistry; D012996:Solutions / Q000737:chemistry; D013237:Stereoisomerism; D013997:Time Factors; D017641:Zeolites / Q000737:chemistry
D002264:Carboxylic Acids; D003521:Cyclopropanes; D012996:Solutions; D017641:Zeolites