Selective Formation of Monoacylated Diols through a Mild Passerini Reaction

The synthesis of both regioisomers of monoacylated diols has been achieved in one simple step using a Passerini reaction. We examined various substrates and reaction conditions, and the results show that the regioselectivity of the reaction is governed by a choice between five- and six-membered-ring transition states, and by different rates of acyl migration under different reaction conditions.