Total Synthesis of Cryptopleurine and its Analogues

Synthesis ◽  
2022 ◽  
Author(s):  
Yousuke Yamaoka ◽  
Takuro Yamakawa ◽  
Kaito Tateishi ◽  
Kiyosei Takasu

Total synthesis of phenanthroquinolizidine alkaloid cryptopleurine was achieved in 8 steps from commercially available 2-pyridinecarboxaldehyde and epoxide derived from methyl eugenol. The key intermediate 5 enables the divergent synthesis of cryptopleurine derivatives by late-stage installation of various substituents on the C-ring.

2019 ◽  
Author(s):  
Timothy Newhouse ◽  
Aneta Turlik ◽  
Yifeng Chen ◽  
Anthony Scruse

<div> <p>The total synthesis of principinol D, a rearranged kaurane diterpenoid, is reported. This grayanane natural product is constructed via a convergent fragment coupling approach, wherein the central 7-membered ring is synthesized at a late stage. The bicyclo[3.2.1]octane fragment is accessed by a Ni-catalyzed α-vinylation reaction. Strategic reductions include a diastereoselective SmI<sub>2</sub>-mediated ketone reduction with PhSH and a new protocol for selective ester reduction in the presence of ketones. The convergent strategy reported herein may be an entry point to the larger class of kaurane diterpenoids.</p> </div>


2018 ◽  
Author(s):  
Yaroslav Boyko ◽  
Christopher Huck ◽  
David Sarlah

<div>The first total synthesis of rhabdastrellic acid A, a highly cytotoxic isomalabaricane triterpenoid, has been accomplished in a linear sequence of 14 steps from commercial geranylacetone. The prominently strained <i>trans-syn-trans</i>-perhydrobenz[<i>e</i>]indene core characteristic of the isomalabaricanes is efficiently accessed in a selective manner for the first time through a rapid, complexity-generating sequence incorporating a reductive radical polyene cyclization, an unprecedented oxidative Rautenstrauch cycloisomerization, and umpolung 𝛼-substitution of a <i>p</i>-toluenesulfonylhydrazone with in situ reductive transposition. A late-stage cross-coupling in concert with a modular approach to polyunsaturated side chains renders this a general strategy for the synthesis of numerous family members of these synthetically challenging and hitherto inaccessible marine triterpenoids.</div>


2019 ◽  
Vol 58 (30) ◽  
pp. 10376-10376
Author(s):  
Hadi Gholami ◽  
Aman Kulshrestha ◽  
Olivia K. Favor ◽  
Richard J. Staples ◽  
Babak Borhan

2019 ◽  
Vol 131 (16) ◽  
pp. 5497-5500 ◽  
Author(s):  
Xiaogang Tong ◽  
Bingfei Shi ◽  
Kangjiang Liang ◽  
Qian Liu ◽  
Chengfeng Xia

2019 ◽  
Vol 17 (14) ◽  
pp. 3552-3566 ◽  
Author(s):  
Ranjan Kumar Acharyya ◽  
Pratik Pal ◽  
Shrestha Chatterjee ◽  
Samik Nanda

An efficient asymmetric total synthesis of naturally occurring γ-Z-butenolide cryptoconcatone I was achieved by employing substrate-directed reductive epoxide ring opening and late-stage “Pd–Cu” catalyzed cascade cyclization.


Synlett ◽  
2020 ◽  
Vol 31 (16) ◽  
pp. 1581-1586
Author(s):  
Imre Pápai ◽  
Petri M. Pihko ◽  
Juha H. Siitonen ◽  
Dániel Csókás

Total syntheses of stemoamide, 9a-epi-stemoamide, and 9a,10-epi-stemoamide by a convergent A + B ring-forming strategy is reported. The synthesis required a diastereoselective late-stage methylation of the ABC stemoamide core that successfully enabled access to three of the four possible diastereomeric structures. For the natural stemoamide series, the diastereoselectivity can be rationalized both by kinetic and thermodynamic arguments, whereas for the natural 9a-epi-stemoamide series, the kinetic selectivity is explained by the prepyramidalization of the relevant enolate.


2017 ◽  
Vol 28 (2) ◽  
pp. 246-249 ◽  
Author(s):  
Perla Ramesh ◽  
Yarram Narasimha Reddy ◽  
Thatikonda Narendar Reddy ◽  
Navuluri Srinivasu

2019 ◽  
Vol 58 (16) ◽  
pp. 5443-5446 ◽  
Author(s):  
Xiaogang Tong ◽  
Bingfei Shi ◽  
Kangjiang Liang ◽  
Qian Liu ◽  
Chengfeng Xia

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