Conjugated dienes are able to react as 1, 2-or 1, 4-dicarbanions by coordination on Ti (II) moiety. These two possibilities are exemplified in this letter with isoprene, myrcene and several aldehydes to give 1, 4-and 1, 6-diols. When allowed to react with esters at room temperature, the titanium–diene complexes lead to cyclopentenol derivatives. Surprisingly, when this reaction is performed at lower temperature (− 40° C), allylic ketones are formed ...