Abstract: | Ethoxycarbonyl group migration in the Wagner-Meerwein rearrangement . 13 β-Hydroxy-esters have been treated with P2O5 in benzene at 80°. Olefin-forming dehydration, when possible, was found to be the main reaction. When this is excluded, tertiary or benzylic hydroxy-esters react in a manner most easily explained by migration of the COOEt group, thus avoiding the formation of α-carbonyl-carbenium ions. On the other hand, in primary hydroxy-esters (incapable of direct olefin formation), phenyl and methyl groups migrate in preference to COOEt, indicating in this case a concerted reaction. |