Intramolecular Diels-Alder cyclizations of (E)-1-Nitro-1,7,9-decatrienes: synthesis of the AB ring system of norzoanthamine.

[formula: see text] Cyclizations of substituted (E)-1-nitro-1,7,9-decatrienes under thermal and Lewis acid conditions have led to the formation of decalin ring systems with excellent endo selectivity. This strategy has been applied to the synthesis of the AB ring system of norzoanthamine.