Stereodivergent Attached-Ring Synthesis via Non-Covalent Interactions: A Short Formal Synthesis of Merrilactone A

A strategy to control the diastereoselectivity of bond formation at a prochiral attached-ring bridgehead is reported. An unusual stereodivergent Michael reaction relies on basic vs. Lewis acidic conditions and non-covalent interactions to control re- vs. si- facial selectivity en route to fully substituted attached-rings. This divergency reflects differential engagement of one rotational isomer of the attached-ring system. The successful synthesis of an erythro subtarget diastereomer ultimately leads to a short formal synthesis of merrilactone A.

Automated summary

A strategy to control the diastereoselectivity of bond formation at a prochiral attached-ring bridgehead was reported, using basic vs. Lewis acidic conditions and non-covalent interactions to achieve facial selectivity. The successful synthesis of an erythro subtarget diastereomer ultimately led to a short formal synthesis of merrilactone A.