Concise total synthesis of (±)-aspidospermidine

2015 ◽  
Vol 13 (18) ◽  
pp. 5255-5259 ◽  
Author(s):  
Haichen Ma ◽  
Xingang Xie ◽  
Peng Jing ◽  
Weiwei Zhang ◽  
Xuegong She
Keyword(s):  
Total Synthesis ◽  
Addition Reaction ◽  
Conjugate Addition ◽  
One Pot ◽  
Carbonyl Reduction

(±)-Aspidospermidine (1) has been synthesized from the commercially available 2,3-dihydro-1H-carbazol-4(9H)-one 6 in 10 steps with 20% overall yield. The key step of the strategy is a one-pot carbonyl reduction/iminium formation/intramolecular conjugate addition reaction that may be applied for the synthesis of other kinds of Aspidosperma alkaloids.

A Concise Total Synthesis of (±)-Mesembrine

Synlett ◽  
2018 ◽  
Vol 29 (09) ◽  
pp. 1203-1206 ◽  
Author(s):  
Hyoungsu Kim ◽  
Hosam Choi ◽  
Kiyoun Lee
Keyword(s):  
Total Synthesis ◽  
Claisen Rearrangement ◽  
Addition Reaction ◽  
Conjugate Addition ◽  
Allylic Oxidation ◽  
Quaternary Stereocenter

A concise total synthesis of (±)-mesembrine has been successfully accomplished in seven steps and 24% overall yield from commercially available 3-ethoxy-2-cyclohexen-1-one. Central to the assembly of the skeleton of mesembrine are a Johnson–Claisen rearrangement for the formation of the benzylic quaternary stereocenter and direct allylic oxidation to generate the substrate for the amidation/transannular aza-conjugate addition reaction.

A One-Pot Chemoenzymatic Synthesis of (2S,4R)-4-Methylproline Enables the First Total Synthesis of Antiviral Lipopeptide Cavinafungin B

2018 ◽  
Author(s):  
Christian R. Zwick ◽  
Hans Renata
Keyword(s):  
Total Synthesis ◽  
Natural Product ◽  
Complex Molecule ◽  
Molecular Target ◽  
Chemoenzymatic Synthesis ◽  
General Strategy ◽  
One Pot

We report an efficient ten-step synthesis of antiviral natural product cavinafungin B in 37% overall yield. By leveraging a one-pot chemoenzymatic synthesis of (2S,4R)-4-methylproline and oxazolidine-tethered (Rink-Boc-ATG-resin) SPPS methodology, the assembly of our molecular target could be conducted in an efficient manner.This general strategy could prove amenable to the construction of other natural and unnatural linear lipopeptides. The value of incorporating biocatalytic steps in complex molecule synthesis is highlighted by this work.

scholarly journals (2S,3R,6R)-2-[(R)-1-Hydroxyallyl]-4,4-dimethoxy-6-methyltetrahydro-2H-pyran-3-ol

Molbank ◽  
10.3390/m1140 ◽  
2020 ◽  
Vol 2020 (2) ◽  
pp. M1140
Author(s):  
Jack Bennett ◽  
Paul Murphy
Keyword(s):  
Mass Spectrometry ◽  
Nmr Spectroscopy ◽  
Ir Spectroscopy ◽  
13C Nmr ◽  
Conjugate Addition ◽  
13C Nmr Spectroscopy ◽  
One Pot ◽  
1H And 13C Nmr ◽  
Esi Mass Spectrometry ◽  
The One

(2S,3R,6R)-2-[(R)-1-Hydroxyallyl]-4,4-dimethoxy-6-methyltetrahydro-2H-pyran-3-ol was isolated in 18% after treating the glucose derived (5R,6S,7R)-5,6,7-tris[(triethylsilyl)oxy]nona-1,8-dien-4-one with (1S)-(+)-10-camphorsulfonic acid (CSA). The one-pot formation of the title compound involved triethylsilyl (TES) removal, alkene isomerization, intramolecular conjugate addition and ketal formation. The compound was characterized by 1H and 13C NMR spectroscopy, ESI mass spectrometry and IR spectroscopy. NMR spectroscopy was used to establish the product structure, including the conformation of its tetrahydropyran ring.

scholarly journals Tandem Fries Reaction–Conjugate Addition under Microwave Irradiation in Dry Media; One-pot Synthesis of Flavanones

1999 ◽  
Vol 23 (9) ◽  
pp. 574-575
Author(s):  
Firouz Matloubi Moghaddam ◽  
Mohammad Ghaffarzadeh ◽  
Seyed Hossein Abdi-Oskoui
Keyword(s):  
Microwave Irradiation ◽  
Silica Gel ◽  
Conjugate Addition ◽  
Solvent Free ◽  
Naphthalene Derivatives ◽  
One Pot ◽  
Fries Rearrangement ◽  
One Pot Synthesis ◽  
Solvent Free Conditions ◽  
Fries Reaction

An AICl3–ZnCl2 mixture supported on silica gel is found to be an efficient medium for the Fries rearrangement of acyloxybenzene or naphthalene derivatives in solvent-free conditions under microwave irradiation.

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