Asymmetric total synthesis of cryptoconcatone I

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.

RSC Advances ◽  
2020 ◽  
Vol 10 (32) ◽  
pp. 18953-18958
Author(s):  
Jihui Li ◽  
Tianxiao Wu ◽  
Xinjing Song ◽  
Yang Zheng ◽  
Jiaxin Meng ◽  
...  

Herein, both CF3COOH-catalyzed (86% ee) and KHMDS-catalyzed (78% ee) chiral epoxide ring-opening cascade cyclization to facile and enantioselective synthesis of the core phthalide tetrahydroisoquinoline scaffold of (−)-β-hydrastine are described.


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

RSC Advances ◽  
2014 ◽  
Vol 4 (28) ◽  
pp. 14468-14470 ◽  
Author(s):  
Subhash P. Chavan ◽  
Kailash P. Pawar ◽  
Sumanta Garai

A protecting group free asymmetric total synthesis of (−)-venlafaxine is reported. The strategy employs Sharpless epoxidation and regio-selective epoxide ring opening by an in situ generated Gilman reagent as key steps. This paper reports a 53% overall yield in 6 steps for total synthesis of (−)-venlafaxine.


2019 ◽  
Vol 17 (31) ◽  
pp. 7369-7379 ◽  
Author(s):  
Joy Chakraborty ◽  
Samik Nanda

An efficient asymmetric total synthesis of naturally occurring resorcylic acid lactone (RAL) paecilomycin C was achieved by employing carboxylate assisted 5-exo-tet ring opening of an epoxide as a key reaction.


2018 ◽  
Vol 16 (27) ◽  
pp. 5027-5035 ◽  
Author(s):  
Ranjan Kumar Acharyya ◽  
Samik Nanda

Asymmetric total synthesis of naturally occurring γ-butenolide containing [4.4]spiro-tetrahydrofuran lanceolactone A has been reported in this present work. Bimetallic (“Pd–Cu”) cascade cyclization was the crucial reaction employed for the construction of the γ-butenolide framework of the natural product.


2015 ◽  
Vol 51 (17) ◽  
pp. 3586-3589 ◽  
Author(s):  
Hideki Abe ◽  
Satoko Itaya ◽  
Kei Sasaki ◽  
Toyoharu Kobayashi ◽  
Hisanaka Ito

Total synthesis of the proposed structure of a polyketide isolated from Phialomyces macrosporus was accomplished. This synthesis features chemoselective epoxidation, regioselective epoxide ring opening, chemo- and diastereoselective dihydroxylation, and vinylation of lactone accompanied by the formation of a furan ring.


Synthesis ◽  
2017 ◽  
Vol 50 (03) ◽  
pp. 663-675
Author(s):  
Pabbaraja Srihari ◽  
Ramakrishna Sayini

The C1–C9 and C10–C24 segments of the 24-membered polyene macrolide macrolactin S were synthesized by routes involving an epoxide-ring-opening reaction, an Ohira–Bestmann alkyne formation, a chelation-controlled nucleophilic addition reaction, and a Still–Gennari olefination as key steps. A chiron approach , starting from readily available glucose diacetonide, was used to synthesize a key intermediate, and a convergent approach was adopted for the synthesis of the key C10–C24 fragment.


2019 ◽  
Vol 21 (17) ◽  
pp. 7149-7153 ◽  
Author(s):  
Jihui Li ◽  
Yongxiang Liu ◽  
Xinjing Song ◽  
Tianxiao Wu ◽  
Jiaxin Meng ◽  
...  

2019 ◽  
Author(s):  
Ke-Yin Ye ◽  
Terry McCallum ◽  
Song Lin

Organic radicals are generally short-lived intermediates with exceptionally high reactivity. Strategically, achieving synthetically useful transformations mediated by organic radicals requires both efficient initiation and selective termination events. Here, we report a new catalytic strategy, namely bimetallic radical redox-relay, in the regio- and stereoselective rearrangement of epoxides to allylic alcohols. This approach exploits the rich redox chemistry of Ti and Co complexes and merges reductive epoxide ring opening (initiation) with hydrogen atom transfer (termination). Critically, upon effecting key bond-forming and -breaking events, Ti and Co catalysts undergo proton-transfer/electron-transfer with one another to achieve turnover, thus constituting a truly synergistic dual catalytic system.<br>


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