Rearrangement Studies with ¹⁴C. XXXVIII. Isotopic Scrambling in the Synthesis of Labeled 2-Phenylethyl Triflate

Abstract

2-Phenylethyl triflate (1-OTf) was synthesized by the reaction of AgOTf with 2-phenylethyl iodide (1-I) in cyclohexane as solvent. However, when 1-14C-2-phenylethyl iodide (1-I-1-14C) was used as a reactant, the resulting 1-OTf-14C showed an essentially complete scrambling of the 14C-label over the C-1 and -2 positions. Similar reactions of 1-I-1-14C with AgOTs and with AgOAc gave 1-OTs-14C and 1-OAc-14C with, respectively, about 49 and 11% rearrangement of the label from C-1 and -2.

Metalation of Oxazole−Borane Complexes: A Practical Solution to the Problem of Electrocyclic Ring Opening of 2-Lithiooxazoles

“…Treating the anion with iodomethane at −20 °C (16 h) afforded 2-methyl-5-phenyloxazole ( 21 ) (74% yield). Attempts to perform a similar alkylation with phenethyl bromide or iodide failed to give significant conversion of 9 , but the corresponding triflate, Ph(CH 2 ) 2 OSO 2 CF 3 , was sufficiently reactive at −20 °C (18 h) and afforded 22 (65% yield). Similarly, oxazole ( 7b ) was alkylated to give 23 (76%)…”