A First Generation Chemoenzymatic Synthesis of (+)-Galanthamine

2010 ◽  
Vol 63 (10) ◽  
pp. 1437 ◽  
Author(s):  
Martin G. Banwell ◽  
Xinghua Ma ◽  
Ochitha P. Karunaratne ◽  
Anthony C. Willis
Keyword(s):  
Total Synthesis ◽  
First Generation ◽  
Claisen Rearrangement ◽  
Starting Material ◽  
Chemoenzymatic Synthesis ◽  
Quaternary Carbon ◽  
Enantiomerically Pure ◽  
Rearrangement Reaction

A total synthesis of (+)-galanthamine [(+)-1] has been achieved using the readily available and enantiomerically pure metabolite 2 as starting material. The quaternary carbon centre (C8a) associated with target 1 was constructed using the Eschenmoser–Claisen rearrangement reaction.

Construction of an asymmetric quaternary carbon via an asymmetric aza-Claisen rearrangement and its application in the total synthesis of (+)-α-cuparenone

2012 ◽  
Vol 23 (10) ◽  
pp. 739-741 ◽  
Author(s):  
Takeshi Nishii ◽  
Fumiaki Miyamae ◽  
Makoto Yoshizuka ◽  
Hiroto Kaku ◽  
Mitsuyo Horikawa ◽  
...  
Keyword(s):  
Total Synthesis ◽  
Claisen Rearrangement ◽  
Quaternary Carbon

scholarly journals Concise total synthesis of two marine natural nucleosides: trachycladines A and B

2014 ◽  
Vol 10 ◽  
pp. 1681-1685 ◽  
Author(s):  
Haixin Ding ◽  
Wei Li ◽  
Zhizhong Ruan ◽  
Ruchun Yang ◽  
Zhijie Mao ◽  
...  
Keyword(s):  
Total Synthesis ◽  
Starting Material ◽  
Chemoenzymatic Synthesis ◽  
Critical Step ◽  
Adenylate Deaminase

We report the first total synthesis of trachycladines A (10 steps, 34.2% overall yield) and B (11 steps, 35.0% overall yield) by using 5-deoxy-1,2,3-tri-O-acetyl-β-D-ribofuranose as the starting material. The critical step was the SnCl4assisted regio- and steroselective deprotection of perbenzylated 1-O-methyl-5-deoxyribofuranose. The enzyme adenylate deaminase (EC 3.5.4.6) was successfully applied to the chemoenzymatic synthesis of trachycladines B.

A Chemoenzymatic Synthesis of the cis-Decalin Core Associated with the Novel Anti-Mitotic Agent Phomopsidin: Some Observations Concerning a High-Pressure-Promoted Diels–Alder Cycloaddition Reaction of (1S,2R)-3-Methyl-cis-1,2-dihydrocatechol and the Anionic Oxy–Cope Rearrangement of Compounds Derived from the Adduct

2004 ◽  
Vol 57 (7) ◽  
pp. 641 ◽  
Author(s):  
Martin G. Banwell ◽  
Alison J. Edwards ◽  
Malcolm D. McLeod ◽  
Scott G. Stewart
Keyword(s):  
Cycloaddition Reaction ◽  
Diels Alder ◽  
Chemoenzymatic Synthesis ◽  
Cope Rearrangement ◽  
The Novel ◽  
X Ray Diffraction ◽  
Enantiomerically Pure ◽  
X Ray ◽  
Wittig Rearrangements ◽  
Rearrangement Reaction

The enantiomerically pure and enzymatically derived cis-1,2-dihydrocatechol 2 engages in a diastereofacially selective Diels–Alder cycloaddition reaction with commercially available lactone 3 at 19 kbar to afford adduct 4, which is readily elaborated to the diene-ol 13. Treatment of this last compound with KH/18[crown]-6 resulted in successive anionic oxy-Cope and 1,2-Wittig rearrangements to afford acyloin 14 embodying the cis-decalin core associated with the natural product phomopsidin (1). Compound 16 also engages in an anionic oxy-Cope rearrangement reaction to give, depending on the molar equivalents of base used, either the cis-decalin 17 or the hexahydroindene 18. The structure of compound 18 has been established by single-crystal X-ray diffraction analysis.

scholarly journals Formal Synthesis of (+)-Madindoline A a Potent IL-6 Inhibitor Utilizing Enzymatic Discrimination of Quaternary Carbon

2013 ◽  
Vol 8 (7) ◽  
pp. 1934578X1300800 ◽  
Author(s):  
Ken-ichi Shimizu ◽  
Mina Tomita ◽  
Ken-ichi Fuhshuku ◽  
Takeshi Sugai ◽  
Mitsuru Shoji
Keyword(s):  
Pure Form ◽  
Starting Material ◽  
Side Chains ◽  
Quaternary Carbon ◽  
Formal Synthesis ◽  
Enantiomerically Pure ◽  
Alkyl Side Chains ◽  
Enzymatic Procedure

A formal synthesis of (+)-madindoline A was achieved. The Sunazuka's key intermediate (4 R,5 S)-(–)-3-butyl-4-( tert-butyldimethylsiloxy)-5-methoxycarbonyl-2,5-dimethyl-2-cyclopentenone was synthesized from easily available (2 S,3 S)-3-acetoxy-2-ethenyl-2-methylcyclopentanone. The starting material was reliably supplied by a chemo-enzymatic procedure in enantiomerically pure form. The synthesis was performed by straightforward transformations involving enone formation and regioselective introduction of the two alkyl side chains.

A Total Synthesis of the Styryllactone (+)-Goniodiol from Naphthalene

2003 ◽  
Vol 56 (6) ◽  
pp. 585 ◽  
Author(s):  
Martin G. Banwell ◽  
Mark J. Coster ◽  
Alison J. Edwards ◽  
Ochitha P. Karunaratne ◽  
Jason A. Smith ◽  
...  
Keyword(s):  
Total Synthesis ◽  
First Generation ◽  
Lithium Perchlorate ◽  
Protecting Group ◽  
Microbial Oxidation ◽  
Ring Closing Metathesis ◽  
Enantiomerically Pure ◽  
Benzylic Alcohol ◽  
Acid Catalyzed ◽  
Metal Catalyzed

The cytotoxic natural product (+)-goniodiol (1) has been prepared in twelve steps from the enantiomerically pure cis-dihydrocatechol (2), which is readily obtained by microbial oxidation of naphthalene. Elaboration of compound (2) involves an initial oxidative cleavage to dialdehyde (7) followed by reduction to give diol (12). Conversion of compound (12) into acetal (17) required, inter alia, selective oxidation of the benzylic alcohol moiety followed by a metal-catalyzed decarbonylation of the resulting aldehyde. Allylation of compound (17) with allyltributylstannane in the presence of lithium perchlorate gave a ca. 2.7 : 1 mixture of alcohols (18) and (19), each of which was converted into the corresponding acrylate under standard conditions. Subjection of these ester derivatives to a ring-closing metathesis (RCM) reaction with Grubbs' first-generation catalyst gave the anticipated lactones (22) and (23). Acid-catalyzed removal of the acetonide protecting group within compound (22) then afforded (+)-goniodiol (1), while analogous deprotection of congener (23) afforded 6-epi-(+)-goniodiol (24).

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.

Recent advances on the synthesis of the antidepressant Paroxetine

2020 ◽  
Vol 27 ◽  
Author(s):  
Joana Santos ◽  
M. Fernanda Proença ◽  
Ana Joao Rodrigues ◽  
Patricia Patrício ◽  
H. Sofia Domingues
Keyword(s):  
Total Synthesis ◽  
Neurological Disorders ◽  
Serotonin Reuptake ◽  
Potent Inhibitor ◽  
Starting Material ◽  
Substitution Pattern ◽  
Biological Probes ◽  
Recent Advances ◽  
Treatment Of Depression ◽  
Made In

: Paroxetine is a potent inhibitor of serotonin reuptake and is widely prescribed for the treatment of depression and other neurological disorders. The synthesis of paroxetine and the possibility to prepare derivatives with a specific substitution pattern that may allow their use as biological probes, is an attractive topic especially for medicinal chemists engaged in neurosciences research. Considering the extensive work that was developed in the last decade on the total synthesis of paroxetine, this review summarizes the most important contributions in this field, organized according to the reagent that was used as starting material. Most of the methods allowed to prepare paroxetine in 4-9 steps with an overall yield of 9-66%. Despite the progress made in this area, there is still room for improvement, searching for new eco-friendly and sustainable synthetic alternatives.

Total Synthesis of Icaritin via Microwave-assistance Claisen Rearrangement

2014 ◽  
Vol 11 (9) ◽  
pp. 677-681 ◽  
Author(s):  
Van-Son Nguyen ◽  
Ling Shi ◽  
Yue Li ◽  
Qiu-An Wang
Keyword(s):  
Total Synthesis ◽  
Claisen Rearrangement ◽  
Microwave Assistance

scholarly journals Recent development and applications of semipinacol rearrangement reactions

2021 ◽  
Author(s):  
Xiao-Ming Zhang ◽  
Bao-Sheng Li ◽  
Shao-Hua Wang ◽  
Kun Zhang ◽  
Fu-Min Zhang ◽  
...  
Keyword(s):  
Total Synthesis ◽  
Quaternary Carbon ◽  
Carbon Formation ◽  
Semipinacol Rearrangement ◽  
Rearrangement Reactions

The recent development of semipinacol rearrangement is reviewed, highlighting its application in β-functionalized ketone synthesis, quaternary carbon formation and total synthesis.

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