Total Synthesis of Epoxyeujindole A

Abstract

The total synthesis of epoxyeujindole A, a structurally unusual indole diterpenoid isolated from Eupenicillium javanicum, has been accomplished for the first time. The synthesis features a late-stage cationic cyclization strategy, which took advantage of an electron-rich olefinic substrate. The CDE ring system was assembled via an enantioselective conjugate addition/alkylation, a Luche cyclization, and a Nozaki-Hiyama-Kishi reaction. The heavily substituted A ring was constructed through a Suzuki-Miyaura coupling and a cationic cyclization, and the bridged fused B ring was formed through a Prins reaction.

Identification and Mechanistic Studies of a Cell Cycle Regulator JP18 from a Library of Synthetic Indole Terpenoid Mimics

“…Recently, we accomplished the total syntheses of a series of naturally occurring indole terpenoids (Scheme A) . From a retrosynthetic point of view, indole terpenoid scaffolds can be disassembled into indole (highlighted in red, Scheme A) and terpenoid (highlighted in blue, Scheme A) motifs in general –,,. Thus, structurally diverse indole terpenoid mimics can be directly prepared from simple indole and terpenoid building blocks (Scheme B), if efficient cross‐coupling‐type reactions are available for forming the linkage bonds (highlighted in cyan, Scheme ).…”

Aflavinines: History, Biology and Total Synthesis

“…Over 30 years after the first total synthesis, Li and co-workers reported the total syntheses of 8,21dehydro-17,20-epoxyeujondole A (panel 8 of Fig. 4) in 2015 [25]. They reported total synthesis of 20-Hydroxy Aflavinine (panel 2 of Fig.…”

Contemporary Synthetic Strategies towards Secosteroids, abeo-Steroids, and Related Triterpenes

“…33,37 A sequence of silylation, hydroboration and oxidation then gave a keto aldehyde, the 2-bromoallylation of which was investigated under various conditions. It was found that most standard protocols such as the Hisomi-Sakurai allylation 38 (TiCl 4 , 2-bromoallylsilane), modified Nozaki-Hiyama conditions 39 (CrCl 2 , LiI, 2,3-dibomopropene) or Barbier-type allylations 40 [In, La(OTf) 3 , 2,3dibromopropene, aq NH 4 Cl] gave similar yields and 1:1 mixtures of C3-epimers of 63. To address the issue of the diastereoselectivity, reagent-based stereocontrol was investigated.…”