Solvolysis Rates and β-Deuterium Secondary Kinetic Isotope Effects of Some Tertiary and Secondary Alk-5-enyl Derivatives. Evidence for ?-Participation

Article abstract of DOI:10.1021/jo00005a038

Tertiary 1,1-dimethylalk-5-enyl chlorides solvolyze in 80percent v/v ethanol with no or moderate rate enhancements attributable to ?-participation.However, secondary β-deuterium kinetic isotope effects (KIE, two deuterated methyl groups) are significantly reduced (k_H/k_D = 1.22-1.57) relative to the saturated analogues (k_H/k_D = 1.80), indicating participation of the double bond.Secondary 1-methylalk-5-enyl tosylates show the same trends, i.e., no or very moderate rate enhancements but reduced β-deuterium secondary KIE relative to the saturated analogue.