Dehydrogenative Intramolecular Macrolactonization of Dihydroxy Compounds Using Ru-MACHO Catalyst.

Herein, we have developed a new approach for the synthesis of 11 to 21-membered macrolactones via intramolecular dehydrogenative coupling of primary alcohols by using Ru-MACHO as a catalyst and Cs 2 CO 3 as a base. This protocol generated 11-21-ring-sized macrocycles (26 derivatives), free from an external oxidant or an additive, eliminating stoichiometric reagents and producing only hydrogen as a byproduct.