Approach to Selective Functionalization of Isoprenoids Kenji UNEYAMA* and Sigeru TORII* This article describes the selective functionalizations of polyisoprenoids by mediator-promoted indirect electrochemical oxidation along with a review of a recent progress in this field. The newly developed electrochemical techniques offer the highly selective epoxidation, chlorinative enetype reaction, and oxyselenenylation-deselenenylati on of polyisoprenoids.