2.5- Dimethylfuran, Diels-Alder additions

The plinols (355), thermal cyclization products of linalool (28) (Vol. 2, p. 61, Refs. 208 and 216 Vol. 4, p. 494, Ref, 285), have been synthesized by a new route, starting with Diels-Alder additions to 2,5-dimethylfuran. The adduct with maleic anhydride was said to be exo-, 356, although no evidence was given, and the only reference quoted concerning this compound does not refer to stereochemistry. The adduct of furan and maleic anhydride is indeed known to be entirely converted to the exo-isomer after initial formation of the endo-... 

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