Migration of hydroxyl in secondary systems during solvolysis in acid solution

A system of compounds has been prepared which is well adapted for displaying the role of trans vicinal, secondary hydroxyl in solvolysis. On methanolysis in acid solution, compounds 5, 7a, and 8a all gave the same products, 9a and 10a, and in practically the same proportions, suggesting that at least one intermediate was common to all three reactions. These intermediates were such that 7a and 8a were not interconverted during the solvolysis, a fact in support of 6 as a common intermediate. Several alternative explanations were shown to be untenable, largely by taking advantage of the remarkable differences between hydroxyl and methoxyl. The work provides the most decisive evidence available for the covalent participation of hydroxyl as a neighbor group in the solvolysis of secondary systems, and contributes also to the study of the reverse reaction, the acid-catalyzed scission of epoxides.