The Reaction of Furan with Maleic Anhydride¹

The use of optically active O-alkyl ester hydrochlorides of L-phenylalanine and L-tyrosine as chiral micellar media for the catalysis of diels-alder reactions

“…For both the tyrosine and phenylalanine hydrochloride surfactant series, increasing the polarity of the solvent from hexane to THF and to water caused an increase in the yield of the reaction. This is in line with what has been previously reported, where the use of aqueous media was found to enhance Diels-Alder reaction [26]. Non-polar solvents reduced both the yield and the selectivity (Table 1, entry 21) of the cycloadduct since reverse micelles are known to be formed in these media [27,28].…”

Diels_Alder reactions in water

“…Before 1980 its use had been reported only incidentally. Diels and Alder themselves performed the reaction between furan and maleic acid in an aqueous medium in 1931 [2], an experiment which was repeated by Woodward and Baer in 1948 [3]. These authors noticed a change in endo-exo selectivity when comparing the reaction in water with that in ether.…”

Diels–Alder adducts of 2-acetoxyfuran as a route to 2,3-functionalized 4-hydroxycyclohexanones. Application of X-ray diffraction to the problem of regio- and stereochemistry

“…Acetylation in pyridine -acetic anhydride yielded a single crystalline diacetate 13 in a 94% yield. The formation of a diacetate (13) in the reaction shows conclusively that reduction of the fused anhydride 4 had taken place only at the carbonyl opposite the hemiketal acetate moiety. In the nmr, diacetate 13 shows clearly the two acetate methyl singlets at 6 2.10 and 2.27 and in the infrared, two characteristic carbonyl absorptions appear at 1750 and 1725 cm-'.…”