PROTONATED CYCLOPROPANES .3. REACTIONS OF LUCAS REAGENT WITH CYCLOPROPANE AND WITH 1-PROPANOL

Passage of cyclopropane through ZnCl2 in 12 M HCl-t resulted in the formation of 1-chloropropane with no detectable 2-chloropropane. The t label was found in all three carbon positions of this product, the isotopic distribution being about 38, 19, and 43%, respectively, at C-1, C-2, and C-3. The reaction of 1-propanol-1-t with ordinary Lucas reagent gave chiefly 1-chloropropane with 4-6% 2-chloropropane. Degradation of this 1-chloropropane showed a total of about 1% isotope position rearrangements, the rearranged isotopic label being about equally distributed at C-2 and C-3. The roles played by equilibrating protonated cyclopropane intermediates in these two reactions and in others suggested by previous tracer work are discussed. © 1968, American Chemical Society. All rights reserved.