Iron(III) 2-ethylhexanoate as a novel, stereoselective hetero-Diels–Alder catalyst
Abstract
Iron(III) 2-ethylhexanoate has been used as a novel, mild Lewis acid catalyst for the stereoselective Diels–Alder reaction of ethyl (E)-4-oxobutenoate with alkyl vinyl ethers to stereoselectively produce cis-2-alkoxy-3,4-dihydro-2H-pyran-4-carboxylic acid, ethyl esters with diastereoisomeric excesses (de) as high as 98%.