Total Synthesis of Ginkgolide C and Formal Syntheses of Ginkgolides A and B.

Ginkgolides are diterpenes isolated from that exhibit strong anti-inflammatory and neuroprotective properties. The highly complex molecular architecture of ginkgolides, combined with their remarkable biological profile, provides a unique platform for the development of new strategies and methods. Herein, we reported the first total synthesis of ginkgolide C and the formal syntheses of ginkgolides A and B.

Syntheses of Cyclopropyl Analogues of Disorazoles A and B and Their Thiazole Counterparts.

Modular syntheses of disorazoles A and B analogues in which the epoxide moieties of the natural products were replaced with cyclopropyl units have been achieved. Targeted as part of a structure-activity relationships study, these syntheses were successfully extended to the thiazole counterparts of these analogues. The retrosynthetically defined fragments were assembled through Yamaguchi esterification, Cu/Pd-catalyzed cross-coupling, Yamaguchi macrolactonization, and Cu-catalyzed cross-coupling as the key reactions.

Modular Total Syntheses of Hyperforin, Papuaforins A, B, and C via Gold(I)-Catalyzed Carbocyclization.

The remarkable biological activities of polyprenylated polycyclic acylphloroglucinols (PPAPs) combined with their highly oxygenated and densely functionalized frameworks have stimulated the interest of synthetic organic chemists over the past decade. Herein, we report the concise total syntheses of four natural products PPAPs, of which some have antibacterial properties, notably hyperforin and papuaforin A. The salient features of this strategy are the short and gram-scalable synthesis of densely substituted PPAPs scaffolds via a Au(I)-catalyzed carbocyclization and the late-stage functionalization for a unified access to a wide variety of PPAPs.

Total Syntheses of Disorazoles A₁ and B₁ and Full Structural Elucidation of Disorazole B₁.

Described herein are the first total syntheses of naturally occurring antitumor agents disorazoles A and B and the full structural assignment of the latter. The syntheses were achieved through convergent strategies employing enantioselective constructions of the required building blocks, including a novel Sharpless epoxidation/enzymatic kinetic resolution of stannane-containing substrates that led selectively to both enantiomeric forms of an epoxy vinyl stannane, and a series of coupling reactions, including a Wittig reaction, a Suzuki coupling, a Stille coupling, a Yamaguchi esterification and a Yamaguchi macrolactonization.

Synthesis and Isolation of Organogold Complexes through a Controlled 1,2-Silyl Migration.

During our efforts toward the synthesis of naturally occurring polyprenylated polycyclic acylphloroglucinol using a Au(I)-catalyzed 6-endo dig carbocyclization, we isolated stable vinyllic gold intermediates. Optimization lead to isolated yields of up to 98%, using 2-(di-tert-butylphosphino)biphenyl as the ligand. This transformation is derived from a silyl rearrangement that can be fully controlled according to the nature of the substituent on the ynone.

Total syntheses of hyperforin and papuaforins A-C, and formal synthesis of nemorosone through a gold(I)-catalyzed carbocyclization.

The remarkable biological activities of polyprenylated polycyclic acylphloroglucinols (PPAPs) combined with their highly decorated bicyclo[3.3.1]nonane-2,4,9-trione frameworks have inspired synthetic organic chemists over the last decade.

One-pot Diels-Alder cycloaddition/gold(I)-catalyzed 6-endo-dig cyclization for the synthesis of the complex bicyclo[3.3.1]alkenone framework.

The rapid synthesis of bicyclo[m.n.1]alkanone cores possessing quaternary carbon centers adjacent to a bridged ketone represents a significant synthetic challenge.

Gold-catalyzed synthesis of carbon-bridged medium-sized rings.

Bicyclo[m.n.1]alkenone frameworks possessing quaternary carbon centers adjacent to a bridged ketone are frequently found in bioactive natural products.