The transmission of substituent effects in isomeric dichloroethano-bridged anthracene derivatives

Abstract The syntheses and characterization of the syn ( 2b ) and anti ( 2a ) isomers of methyl- cis -11,12-dichloro-9,10-dihydro-9,10-ethano 2-anthroate as well as methyl-9,10-dihydro-9,10-ethano 2-anthroate ( 2c ) are described. Geometric assignments for 2a and 2b were based upon dipole moments and chemical degradation. The rates of base-catalyzed hydrolyses of the three esters in aqueous ethanol are reported. The acid dissociation constants for the corresponding three bridged-anthracene carboxylic acids 3a , 3b and 3c in aqueous methanol and their rates of reaction with diphenyldiazomethane in ethanol and in toluene have been measured. The angular dependence of the substituent effects in this system is discussed.