J . Am. Chem. SOC. 1980, 102, 5798-5809
5798
analysis of the kinetic data difficult, if not impossible. The absence of a kinetic isotope effect suggests (but does not prove) that proton transfer occurs after the rate-determining formation of a 5-coordinate intermediate (eq 18). This mechOAs(OR),
+ R’OH 2 OAs(OR),(OHR‘)
It
(18 )
OAs(OR),(OR’) t R O H 2 OAS(OR),(OR’)
