Transition-Metal-Mediated Dihydropyran Syntheses. Exo Selective Hetero Diels−Alder Reactions of Cobaloxime Dienyl Complexes with Aldehydes

Methyl ricinoleate as platform chemical for simultaneous production of fine chemicals and polymer precursors

The modification of methyl ricinoleate by etherification of the hydroxyl group was accomplished by using a nonclassical ruthenium-catalyzed allylation reaction and also by esterification. Methyl ricinoleate derivatives were engaged in ring-closing metathesis (RCM) reactions leading to biosourced 3,6-dihydropyran and α,β-unsaturated lactone derivatives with concomitant production of polymer precursors. Sequential RCM/hydrogenation and RCM/cross-metathesis were also implemented as a straightforward method for the synthesis of tetrahydropyran and lactone derivatives as well as valuable monomers (i.e., polyamide precursors).