The influence of cobalt(II) and tin(II) chloride on regioselectivity and kinetics of phenylselenocyclization of 6-methyl-hept-5-en-2-ol.

The reaction of the Δ-alkenols with PhSeX can follow three possible reaction pathways: two pathways lead to the formation of two regioisomeric cyclic ether products through the process of intramolecular cyclization, while the third represents the addition of the reagent to the double bond of an alkenol. As there are relatively few literature data on the kinetics of these reactions, we have chosen 6-methyl-hept-5-en-2-ol as a substrate of interest in order to obtain valuable results that will enable better understanding of the mechanism of phenylselenoetherification reactions. 6-Methyl-hept-5-en-2-ol is a particularly interesting model-substrate due to its substitution pattern of functional groups involved in the cyclization process. In this research, through synthetic and kinetic studies, we aimed to resolve key questions concerning the influence on kinetics, chemo- and regioselectivity of the reagent's counter ion, steric hindrances in substrate functional groups and the presence of additives.