A preparatively efficient method for the synthesis o f the substrate 10 i s described. T h i s undergoes a n intramolecular [4 t 21 cycloaddition t o give the lactam 11. Reduction of the amide carbonyl gives 6, t h e product of a n extremely facile [4 t 21 cycloreversion, a n d n o trace o f t h e Diels-Alder adduct 7 was found. A number o f transformations o f 11, including a skeletal rearrangement o f 14 t o 16, are described, and the structure a n d relative stereochemistry of t h e products is elaborated largely o n the basis o f their NMR data. T h e cis stereochemistry o f 20, a product obtained f r o m t h e cycloadduct 11 v i a hydrogenation, eliminative ether cleavage, a n d hydrogenation, is established by correlation w i t h a relay compound 27, independently synthesized via a bimolecular Diels-Alder reaction.

Die Umsetzung von α‐Brommethyl‐styrol (I) mit N‐Methyl= furfurylamin (II) ergibt das Substitutionsprodukt (III), das jedoch nicht zu (IV) cyclisiert.