The chemistry of thujone. XVII. The synthesis of ambergris fragrances and related analogues

1994 ◽  
Vol 72 (6) ◽  
pp. 1570-1581 ◽  
Author(s):  
James P. Kutney ◽  
Yong-Huang Chen
Keyword(s):  
Ring Opening ◽  
Sodium Acetate ◽  
Ring Closure ◽  
Side Chain ◽  
Synthetic Route ◽  
Acid Catalyzed ◽  
Robinson Annulation

A strategy to utilize the thujone-derived enone 1 for the development of a synthetic route to ambergris fragrances is presented. Thujone (8) is transformed to the tricyclic enone 9, via the Robinson annulation reaction, and the latter is then elaborated to the cis-fused tricyclic intermediates 10, 11, and 12. Extrusion of the isopropyl side chain in 12 is achieved through an initial ozonation reaction and the resulting ketone 14 is then treated with m-CPBA to afford 16. Cyclopropyl ring opening in 16 is performed via initial saponification to the alcohol 17 and the latter is then reacted with FeCl3 and sodium acetate to enone 1. The necessary elaboration of a tetrahydrofuran ring attached to ring B of 1 is achieved through reaction of 1 with vinylmagnesium bromide, alkylation, hydroboration, and final acid-catalyzed ring closure of the 1,5-diol 4. The route affords the opportunity of synthesizing a variety of analogues within the Ambrox series.

Furan ring opening–pyrrole ring closure: a new synthetic route to aryl(heteroaryl)-annulated pyrrolo[1,2-a][1,4]diazepines

2010 ◽  
Vol 8 (14) ◽  
pp. 3316 ◽  
Author(s):  
Alexander V. Butin ◽  
Tatyana A. Nevolina ◽  
Vitaly A. Shcherbinin ◽  
Igor V. Trushkov ◽  
Dmitry A. Cheshkov ◽  
...  
Keyword(s):  
Ring Opening ◽  
Furan Ring ◽  
Pyrrole Ring ◽  
Ring Closure ◽  
Synthetic Route

ChemInform Abstract: Furan Ring Opening-Pyrrole Ring Closure: A New Synthetic Route to Aryl(heteroaryl)-Annulated Pyrrolo[1,2-a][1,4]diazepines.

ChemInform ◽  
2010 ◽  
Vol 41 (49) ◽  
pp. no-no
Author(s):  
Alexander V. Butin ◽  
Tatyana A. Nevolina ◽  
Vitaly A. Shcherbinin ◽  
Igor V. Trushkov ◽  
Dmitry A. Cheshkov ◽  
...  
Keyword(s):  
Ring Opening ◽  
Furan Ring ◽  
Pyrrole Ring ◽  
Ring Closure ◽  
Synthetic Route

Synthesis of Methyl 1, 5‐Diaryl‐1H ‐pyrrole‐2‐carboxylates via Acid‐catalyzed Ring‐opening/Ring‐closure Sequence

2021 ◽  
Author(s):  
Long Huang ◽  
Chenghao Luo ◽  
Pan Pan Xu ◽  
Bing Liu ◽  
Duntie Zhang ◽  
...  
Keyword(s):  
Ring Opening ◽  
Ring Closure ◽  
Acid Catalyzed

Synthetic route to chiral indolines via Cu(OAc)2-catalyzed ring-opening/C(sp2)–H activation of activated aziridines

2017 ◽  
Vol 53 (74) ◽  
pp. 10263-10266 ◽  
Author(s):  
Abhijit Mal ◽  
Gaurav Goswami ◽  
Imtiyaz Ahmad Wani ◽  
Manas K. Ghorai
Keyword(s):  
Lewis Acid ◽  
Ring Opening ◽  
Synthetic Route ◽  
One Pot ◽  
Acid Catalyzed

A novel synthetic route to functionalized indolinesviaLewis acid catalyzed ring-opening of activated aziridines followed by Cu(OAc)2-mediated intramolecular C–H amination in one-pot with excellent enantio- and diastereospecificity (ee 99%; de >99%).

Stereoselective synthesis of 3-spiropiperidino indoleninesviaSN2-type ring opening of activated aziridines with 1H-indoles/Pd-catalyzed spirocyclization with propargyl carbonates

2018 ◽  
Vol 54 (62) ◽  
pp. 8583-8586 ◽  
Author(s):  
Sajan Pradhan ◽  
Chandan Kumar Shahi ◽  
Aditya Bhattacharyya ◽  
Manas K. Ghorai
Keyword(s):  
Lewis Acid ◽  
Ring Opening ◽  
Stereoselective Synthesis ◽  
Synthetic Route ◽  
Acid Catalyzed ◽  
High Yields

A novel synthetic route to 3-spiropiperidino indoleninesviaLewis acid catalyzed SN2-type ring opening of activated aziridines with 1H-indoles followed by Pd-catalyzed spirocyclization with propargyl carbonates in high yields (up to 88%) with excellent diastereo- and enantiospecificity (dr >99 : 1; ee up to >99) is reported.

scholarly journals A New Approach to the Total Synthesıs of (±)-Nordasycarpıdone by Rıng-closure wıth Tetrachloro-1,4-benzoquınone

2020 ◽  
Vol 39 (1) ◽  
pp. 11
Author(s):  
Nesimi Uludag
Keyword(s):  
Molecular Structure ◽  
Total Synthesis ◽  
Ring Closure ◽  
Cyclization Reaction ◽  
Side Chain ◽  
Synthetic Route ◽  
New Approach

A new synthetic route for the  (±)-nordasycarpidone was achieved in five steps with an overall yield of  41%. This route involves  ring closure and formation of 5 which has a  methanoazocino[4,3-b]indole skeleton in the key step. The reaction also involved a cyclization reaction of  tetrahydrocarbazole with a monoalkyl nitrile side chain at the C-2 position, and this reaction was mediated by tetrachloro-1,4-benzoquinone (TCB). The central step in the synthesis was  the closure of the D-ring of the intra-molecular structure and the addition of amine, which resulted in an aza-tetracyclic substructure that contained the ABCD-ring of the strychnos alkaloid family.

scholarly journals An acid catalyzed reversible ring-opening/ring-closure reaction involving a cyano-rhodamine spirolactam

2013 ◽  
Vol 11 (11) ◽  
pp. 1805 ◽  
Author(s):  
Honglin Li ◽  
Hong Guan ◽  
Xinrui Duan ◽  
Jun Hu ◽  
Guiren Wang ◽  
...  
Keyword(s):  
Ring Opening ◽  
Ring Closure ◽  
Acid Catalyzed

scholarly journals A moisture-tolerant route to unprotected α/β-amino acid N-carboxyanhydrides and facile synthesis of hyperbranched polypeptides

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Zi-You Tian ◽  
Zhengchu Zhang ◽  
Shuo Wang ◽  
Hua Lu
Keyword(s):  
Amino Acid ◽  
Functional Groups ◽  
Protein Modification ◽  
Water Soluble ◽  
Ring Closure ◽  
High Yield ◽  
Side Chain ◽  
Facile Synthesis ◽  
Synthetic Polypeptides ◽  
Acid Catalyzed

AbstractA great hurdle in the production of synthetic polypeptides lies in the access of N-carboxyanhydrides (NCA) monomers, which requires dry solvents, Schlenk line/gloveboxe, and protection of side-chain functional groups. Here we report a robust method for preparing unprotected NCA monomers in air and under moisture. The method employs epoxy compounds as ultra-fast scavengers of hydrogen chloride to allow assisted ring-closure and prevent NCA from acid-catalyzed decomposition under moist conditions. The broad scope and functional group tolerance of the method are demonstrated by the facile synthesis of over 30 different α/β-amino acid NCAs, including many otherwise inaccessible compounds with reactive functional groups, at high yield, high purity, and up to decagram scales. The utility of the method and the unprotected NCAs is demonstrated by the facile synthesis of two water-soluble polypeptides that are promising candidates for drug delivery and protein modification. Overall, our strategy holds great potential for facilitating the synthesis of NCA and expanding the industrial application of synthetic polypeptides.

scholarly journals Synthesis of 3,3-Diaryl/Heteroarylpropylamines via Nucleophilic Ring Opening of Activated Azetidines with Arenes and Heteroarenes: New Synthetic Route to (±)Tolterodine

ACS Omega ◽  
2018 ◽  
Vol 3 (12) ◽  
pp. 17562-17572 ◽  
Author(s):  
Gaurav Goswami ◽  
Navya Chauhan ◽  
Abhijit Mal ◽  
Subhomoy Das ◽  
Mowpriya Das ◽  
...  
Keyword(s):  
Ring Opening ◽  
Synthetic Route ◽  
Nucleophilic Ring Opening
Sign in / Sign up

Export Citation Format

Share Document