Synthesis of Chiral, Fused Tricyclic Molecules by Sequential Metal‐Catalyzed Reactions of Simple Substrates

A set of complex tricyclic compounds containing several functional groups and multiple stereogenic centers has been prepared in only two steps with excellent diastereo- enantioselectivities. The synthesis takes advantage the highly versatile enantioselective Pd-catalyzed allylic substitution simple cyclic acetates or carbonates to form chiral 1,6-, 1,7- 1,8-enynes, which are then diastereoselectively transformed corresponding cyclopentenone- cyclobutene-based compounds.