Download full text in PDF Opens in a new window. Article suggestions will be shown in a dialog on return to ScienceDirect. ... Please enable JavaScript to use all the features on this page. ... Formation of seven- and eight-membered rings by manganese (III)-based oxidative free radical cyclization. ... Oxidative free radical cyclizations of β-ketoesters 1, 5, 11, and 14 with Mn(OAc) 3 ·2H 2 O and Cu(OAc) 2 ·H 2 O proceed in moderate yield to give seven- and ...