The Determination of Internal Return

The Determination of Internal Return The well-known phenomenon of internal return (Young et al., 1951 Winstein and Trifan, 1952) was first recognized through the discrepancies which existed between the titrimetric (fcj) and polarimetrio k,) rate constants during certain first-order solvolyses. During the acetolysis of optically active ea o-2-bicyclo[2,2,l]heptyl tosylate (57, Y = OTs), for example, it was noticed that racemization occurred 

Determination of Internal Return Using Carbon-14 (Jenny and Winstein, 1958)  

---