Kinetic analysis reveals oxygen-18 scrambling during solvolysis of 1-(3-nitrophenyl)ethyl tosylate, suggesting an isomerization pathway bypassing carbocation intermediates.
[reaction: see text] There is substantial isomerization (kiso=0.32 x 10(-3) s(-1)) of 3-NO2C6H4(13)CH(Me)OS(18O)2Tos during solvolysis (ksolv=1.04 x 10(-3) s(-1)) in 50/50 trifluoroethanol/water, even though the estimated lifetime of the putative 1-(3-nitrophenyl)ethyl carbocation intermediate of solvolysis (ca. 10(-13) s(-1)) is too short to allow rearrangement that exchanges the positions of 16O and 18O at the sulfonate leaving group. This suggests that isomerization proceeds by a mechanism that avoids formation of the carbocation-anion pair intermediate.
No takes yet. Share an insight, caveat, or question.
Tsuji et al. (2004) studied this question.
Synapse has enriched 5 closely related papers on similar clinical questions. Consider them for comparative context: