Construction of azaspirocyclic skeletons mediated by the carbonyl of Weinreb amide: formal total synthesis of (±)-cephalotaxine

Author(s):  
Jian Zhang ◽  
Jianyin Liu ◽  
Yuxue Fan ◽  
Huili Ding ◽  
Tianfu Liu ◽  
...  

Facile stevens rearrangement of the Weinreb amide and the subsequent key steps mediated by the carbonyl of Weinreb amide led to the construction of azaspirocyclic skeletons of some typical alkaloids....

Synlett ◽  
2020 ◽  
Author(s):  
Debendra K. Mohapatra ◽  
Shivalal Banoth ◽  
Utkal Mani Choudhury ◽  
Kanakaraju Marumudi ◽  
Ajit C. Kunwar

AbstractA concise and convergent stereoselective synthesis of curvulone B is described. The synthesis utilized a tandem isomerization followed by C–O and C–C bond-forming reactions following Mukaiyama-type aldol conditions for the construction of the trans-2,6-disubstituted dihydropyran ring system as the key steps. Other important features of this synthesis are a cross-metathesis, epimerization, and Friedel–Crafts acylation.


2010 ◽  
Vol 65 (4) ◽  
pp. 445-451 ◽  
Author(s):  
René Csuk ◽  
Erik Prell ◽  
Stefan Reißmann ◽  
Claudia Korb

A straightforward chiral pool synthesis for the first fluorinated calystegin is described. Key steps of this synthesis include an ultrasound-assisted Zn-mediated tandem ring opening reaction followed by a Grubbs’ catalyst-mediated ring closure metathesis reaction. The target compound is a selective and competitive inhibitor for a β -glycosidase.


2017 ◽  
Vol 15 (44) ◽  
pp. 9408-9414 ◽  
Author(s):  
Jakub Smrček ◽  
Radek Pohl ◽  
Ullrich Jahn

A parallel total synthesis of 16-F1t-, 16-E1-phytoprostanes and a first synthesis of 16-D1t-phytoprostanes based on a common precursor are described.


SynOpen ◽  
2019 ◽  
Vol 03 (02) ◽  
pp. 49-54 ◽  
Author(s):  
Anil Talakokkula ◽  
Karunakar Baikadi ◽  
A. Narsaiah

The total syntheses of artekeiskeanol A and C, and altissimacoumarin D have been achieved. The syntheses commenced from commercially available starting materials, 2,4-dihydroxybenzaldehyde and geraniol. The key steps involve Wittig and Riley oxidation reactions.


2019 ◽  
Vol 17 (31) ◽  
pp. 7325-7329
Author(s):  
Naoyuki Shimada ◽  
Kenji Fukuhara ◽  
Sari Urata ◽  
Kazuishi Makino

Total synthesis of seminolipid was accomplished via regioselective protection using 2,6-bis(trifluoromethyl)phenylboronic acid followed by regioselective trichloroethyl-protected sulfation as key steps.


2018 ◽  
Vol 16 (33) ◽  
pp. 5979-5986 ◽  
Author(s):  
Arun K. Ghosh ◽  
Hannah M. Simpson ◽  
Anne M. Veitschegger

Enantioselective syntheses of decytospolides are described using an Achmatowicz rearrangement, transfer hydrogenation and Friedel–Crafts acylation as the key steps.


2015 ◽  
Vol 2 (5) ◽  
pp. 548-551 ◽  
Author(s):  
Dattatraya H. Dethe ◽  
Vijay Kumar B

Concise biomimetic and asymmetric approach involving Sharpless asymmetric dihydroxylation and Lewis acid catalysed cyclopenta[b]annulation as key steps to synthesize (+)-bruceolline J.


Marine Drugs ◽  
2019 ◽  
Vol 17 (4) ◽  
pp. 226 ◽  
Author(s):  
Haixin Ding ◽  
Zhizhong Ruan ◽  
Peihao Kou ◽  
Xiangyou Dong ◽  
Jiang Bai ◽  
...  

The first total synthesis of the marine nucleoside Mycalisine B—a naturally occurring and structurally distinct 4,5-unsaturated 7-deazapurine nucleoside—has been accomplished in 10 linear steps with 27.5% overall yield from commercially available 1,2,3,5-tetra-O-acetyl-ribose and tetracyanoethylene. Key steps of the approach include: (1) I2 catalyzed acetonide formation from 1,2,3,5-tetra-O-acetylribose and acetone at large scale; (2) Vorbrüggen glycosylation using N4-benzoyl-5-cyano-6-bromo-7H-pyrrolo[2,3–d]pyrimidine as a nucleobase to avoid formation of N-3 isomer; (3) mild and scalable reaction conditions.


2018 ◽  
Vol 13 (7) ◽  
pp. 1934578X1801300
Author(s):  
Dandekar Chandrakanth ◽  
Yerragorla Gopala Rao ◽  
Tallapally Swamy ◽  
Dhanraj O Biradar ◽  
Lonavath Vishnupriya ◽  
...  

A stereoselective total synthesis of an antiproliferative and antifungal natural product, (6 S)-5,6-dihydro-6-[(2 R)-2-hydroxy-6-phenylhexyl]-2 H-pyran-2-one has been accomplished using the Barbier allylation, LiAlH4/LiI mediated syn-stereoselective reduction and olefin ring-closing metathesis (RCM) as the key steps. L-Malic acid was used as a chiral precursor for the construction of syn-1,3-diol moiety of the molecule.


SynOpen ◽  
2019 ◽  
Vol 03 (02) ◽  
pp. 59-66
Author(s):  
Ambati Sharada ◽  
Lakshmi Srinivasa Rao Kundeti ◽  
Kallaganti V. S. Ramakrishna ◽  
Kommu Nagaiah

The acetylene derivative Ciryneol C was isolated from the roots of C. japonicum. The asymmetric total synthesis of Ciryneol C was achieved in seven steps, with Horner–Wittig olefination, regioselective epoxide opening, and Cadiot–Chodkiewicz coupling reactions being the key steps.


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