An asymmetric approach for the first total synthesis of (−)-rhodomollanol A, a highly oxidized diterpenoid, is described. The efficient synthetic strategy features three key transformations: (1) an oxidative dearomatization-induced (5 + 2) cycloaddition/pinacol-type 1,2-acyl migration cascade to build up the bicyclo­[3.2.1]­octane skeleton; (2) a retro-Dieckmann fragmentation/vinylogous Dieckmann cyclization cascade to assemble the bicyclo­[3.3.0]­octane subunit; and (3) a photo-Nazarov cyclization/intramolecular cycloetherification cascade to forge the 7-oxabicyclo­[4.2.1]­nonane core structure of the natural product.

An asymmetric and efficient approach for the total syntheses of (+)-stemarin and the proposed structures of stemara-13(14)-en-18-ol and stemara-13(14)-en-17-acetoxy-18-ol are described. The key features of the strategy include a Lewis acid-induced cationic polyene cyclization and an ODI-[5+2] cycloaddition/pinacol-type 1,2-acyl migration cascade.

The asymmetric total syntheses of (+)‐vulgarisins A–E, which share a rare and highly oxygenated [5‐6‐4‐5] tetracyclic core structure that were isolated from P. vulgaris Linn., have been described for the first time in a divergent manner. Key transformations include: 1) a catalytic asymmetric intramolecular cyclopropanation to forge the A ring bearing desired stereochemistry at C14; 2) a one‐pot borylation/conjugate addition process for creation of the C1−C11 bond; 3) a Wolff ring contraction to assemble the bicyclo[3.2.0]heptane subunit (CD rings); and 4) a stereocontrolled pinacol cyclization for construction of the central B ring of the natural products.

The asymmetric total syntheses of (+)‐vulgarisins A–E, which share a rare and highly oxygenated [5‐6‐4‐5] tetracyclic core structure that were isolated from P. vulgaris Linn., have been described for the first time in a divergent manner. Key transformations include: 1) a catalytic asymmetric intramolecular cyclopropanation to forge the A ring bearing desired stereochemistry at C14; 2) a one‐pot borylation/conjugate addition process for creation of the C1−C11 bond; 3) a Wolff ring contraction to assemble the bicyclo[3.2.0]heptane subunit (CD rings); and 4) a stereocontrolled pinacol cyclization for construction of the central B ring of the natural products.