65110-04-5Relevant academic research and scientific papers
Electrochemically-induced spirolactonization of α-(methoxyphenoxy)alkanoic acids into quinone ketals
Deffieux, Denis,Fabre, Isabelle,Courseille, Christian,Quideau, Stephane
, p. 4458 - 4465 (2007/10/03)
Anodic oxidation of two series of α-(2)- and α-(4-methoxyphenoxy)alkanoic acids were studied both at the analytical and preparative scales in order to delineate mechanistic aspects of electrochemically induced spirolactonization and to develop synthetically useful orthoquinone bis- and monoketals. Although α-monomethylated carboxylic acids and acetic acid derivatives do not undergo any spiroannulation, α-dimethylated carboxylic acids furnished spirolactones in high yields. A gem-dimethyl effect is invoked to explain these differences in cyclization capacity. Electrooxidation conditions can be selected to furnish either quinone spirolactone bis- or monoketals. Chemoselective monohydrolysis of bisketals can also be accomplished in a stepwise fashion to furnish the corresponding spirolactone monoketals, but the ortho compound unfortunately dimerized in situ via a Diels-Alder process. An ECEC pathway is proposed to rationalize the observed spirolactonizations on the basis of cyclic voltammetry analyses.
1,4-DIOXASPIRODECA-6,9-DIEN-2,8-DIONE DURCH ANODISCHE OXIDATION VON 4-METHOXYPHENOXYESSIGSAEUREN
Thomas, H. G.,Schwager, H.-W.
, p. 4471 - 4474 (2007/10/02)
On preparative anodic oxidation in acetonitrile at graphite electrodes 4-methoxyphenoxyacetic acids 1 cyclize to 1,4-dioxaspirodeca-6,9-dien-2,8-diones 2.Electroanalytical results are given.
