Diene-Transmissive Enantioselective Diels-Alder Reactions and Sequences Involving Substituted Dendralenes

Readily available and stable substituted [3]-dendralenes undergo highly chemo-, regio-, diastereo-, and enantioselective organocatalyzed Diels-Alder reactions with acrolein to form enantiomerically enriched cycloadducts. These monocycloadducts carry semicyclic dienes that undergo a second, substrate-controlled diastereoselective Diels-Alder reaction with a different dienophile to form 2-fold cycloadducts. Overall, annulated, functional group rich, chiral Delta(1(9))-octalin building blocks are accessed in one-pot operations that significantly extend the preparative value of diene-transmissive Diels-Alder sequences since they offer products stereochemistry complementary to those generated from the parent, unsubstituted [3]dendralene.