Aliphatic Ketone Claisen Rearrangement: Troubleshooting the Transetherification Step by Identifying a Stable Acid Catalyst.

After optimization for retention of catalytic activity, 4-chlorobenzoic acid emerged as the optimal catalyst for the aliphatic ketone Claisen rearrangement. The optimal catalyst enables a one-pot, metal-free, catalytic protocol from allylic alcohols to γ,δ-unsaturated ketones. The optimized process tolerates a range of substrates, including substituents with acid-labile protecting groups.

Humilisin E: Strategy for the Synthesis and Access to the Functionalized Bicyclic Core.

Humilisin E is a diterpenoid possessing a rare epoxidized cyclononene -fused with a bicyclo[3.2.0]heptane core.