Protonated cyclopropanes. IV. Trifluoroacetolysis of 1-14C-1-propyl tosylate

Abstract

The trifluoroacetolysis of 1-14C-1-propyl tosylate was carried out either with or without the presence of an equivalent of sodium trifluoroacetate. Both 1-propyl and 2-propyl trifluoroacetates were obtained, the latter being the major product if the sodium salt was not present. Isotope position rearrangements from C-1 to C-2 and C-3 were observed in the 1-propyl trifluoroacetate to the extent of about 2 and 17%, respectively, for the reactions effected with and without sodium trifluoroacetate. The rearranged 14C label was about equally distributed at C-2 and C-3. It is proposed that these rearrangements may be explained on the assumption that part of the overall reaction proceeds through equilibrating protonated cyclopropane intermediates.