Scrambling of oxygen-18 during the "borderline" solvolysis of 1-(3-nitrophenyl)ethyl tosylate.
[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.
Tsuji
Yutaka
Y
Department of Biochemistry and Applied Chemistry, Kurume National College of Technology, Komorinomachi, Kurume 830-8555, Japan.
Toteva
Maria M
MM
Amyes
Tina L
TL
Richard
John P
JP
D000838:Anions / Q000737:chemistry; D002244:Carbon / Q000737:chemistry*; D007536:Isomerism; D008956:Models, Chemical; D015394:Molecular Structure; D009578:Nitrobenzenes / Q000737:chemistry*; D010100:Oxygen / Q000737:chemistry; D010103:Oxygen Isotopes / Q000737:chemistry*; D012997:Solvents / Q000737:chemistry
C504943:1-(3-nitrophenyl)ethyl tosylate; D000838:Anions; D009578:Nitrobenzenes; D010103:Oxygen Isotopes; D012997:Solvents; D002244:Carbon; D010100:Oxygen