ChemInform Abstract: DABCO-Catalyzed Coupling of Aldehydes with Activated Double Bonds. Part 6. Stereoselective Generation and Facile Dimerization of E-2-Methylene-3-alkenoic Acid Esters.
Abstract
The aldehydes (I) are coupled with methyl acrylate (II) in the presence of 1,4-diazabicyclo(2.2.2)octane (DABCO) to yield the 2-(1-hydroxyalkyl)acrylates (III).
ChemInform Abstract
The aldehydes (I) are coupled with methyl acrylate (II) in the presence of 1,4-diazabicyclo(2.2.2)octane (DABCO) to yield the 2-(1-hydroxyalkyl)acrylates (III). In some cases, the formation of 2:1 adducts such as (IV) or of lactones such as (VI) is also observed. The compounds (III) are dimerized upon treatment with mesyl chloride and DABCO, producing a mixture of the diastereomeric cyclohexenedicarboxylates (VII) and (VIII). The derivative (VIIb) is converted to the anthrone (XI) via intramolecular Friedel-Crafts acylation of the bis(acid chloride) (IX). (Mechanism, transition states, X ray investigations).
