A New Enantioselective Total Synthesis of Natural Vincamineviaan IntramolecularMannichReaction of an Silyl Enol Ether

1977 ◽  
Vol 60 (5) ◽  
pp. 1801-1810 ◽  
Author(s):  
Wolfgang Oppolzer ◽  
Hartmut Hauth ◽  
Paul Pfäffli ◽  
Roland Wenger
Keyword(s):  
Total Synthesis ◽  
Enol Ether ◽  
Enantioselective Total Synthesis ◽  
Silyl Enol Ether

A total synthesis of a protected form of the secoxyloganin aglucone

1989 ◽  
Vol 67 (2) ◽  
pp. 261-267 ◽  
Author(s):  
Peter T. W. Cheng ◽  
Stewart McLean
Keyword(s):  
Total Synthesis ◽  
Functional Groups ◽  
Oxidation State ◽  
Oxidative Cleavage ◽  
Enol Ether ◽  
Silyl Enol Ether ◽  
Carbon Framework ◽  
High Yields

A synthesis is described that leads from cyclopentadiene through 5-norbornen-2-one to the monosubstituted cyclopentenone 5; a vinyl substituent is attached by the reaction of a cuprate, and the enolate intermediate is trapped as the silyl enol ether 4, which is converted to 19, a product with the 10-carbon framework and stereochemistry of the secoxyloganin aglucone, and with all functional groups differentially protected and in the correct oxidation state. Explorations of the cuprate reaction required to convert the cyclopentenone 5 to the siloxycyclopentene 4 and of the reactions required for the oxidative cleavage of 4 reveal problems with these reactions when they are applied to compounds that are cyclopentane derivatives. The resolution of these problems leads to reaction sequences that proceed with high yields and excellent diastereoselectivity. Keywords: synthesis, secoxyloganin, vinyl cuprate, oxidative cleavage.

Total synthesis of (−)-agelastatin A: an SH2′ radical azidation strategy

2018 ◽  
Vol 54 (71) ◽  
pp. 9893-9896 ◽  
Author(s):  
Izuru Tsuchimochi ◽  
Yuta Kitamura ◽  
Hiroshi Aoyama ◽  
Shuji Akai ◽  
Keiyo Nakai ◽  
...  
Keyword(s):  
Total Synthesis ◽  
Synthetic Approach ◽  
Enol Ether ◽  
Agelastatin A ◽  
Silyl Enol Ether ◽  
Strategic Implementation ◽  
Allylic Bromide

A new synthetic approach to (−)-agelastatin A has been established through the strategic implementation of brominative olefin transposition of a silyl enol ether and subsequent SH2′ radical azidation of the resultant allylic bromide.

scholarly journals Bioinspired Divergent Oxidative Cyclization of Strictosidine and Vincoside Derivatives: Second Generation Enantioselective Total Synthesis of (–)-Cymoside

2020 ◽  
Author(s):  
Yingchao Dou ◽  
Cyrille Kouklovsky ◽  
Guillaume Vincent
Keyword(s):  
Total Synthesis ◽  
Second Generation ◽  
Oxidative Cyclization ◽  
Enol Ether ◽  
Enantioselective Total Synthesis ◽  
Terminal Alkene

<p>We report our second generation synthesis of (–)-cymoside as well as the formation of a new hexacyclic-fused furo[3,2-<i>b</i>]indoline framework. After a Pictet-Spengler condensation between secologanin tetraacetate and tryptamine, the course of the cyclization of the 7-hydroxyindolenine intermediate generated by oxidation with an oxaziridine, depends on the stereochemistry of the 3-position. The 3<i>-(S)-</i>strictosidine stereochemistry delivered efficiently the scaffold of cymoside via intramolecular coupling with the C16-C17 enol ether, while the 3<i>-(R)-</i>vincoside stereochemistry directed towards the reaction with the C18-C19 terminal alkene and the formation of the unexpected caged compound.</p>

Total Synthesis of (±)-Cephalosol via Silyl Enol Ether Acylation

Synthesis ◽  
2010 ◽  
Vol 2010 (06) ◽  
pp. 917-922 ◽  
Author(s):  
Ulrich Koert ◽  
Alexander Arlt
Keyword(s):  
Total Synthesis ◽  
Enol Ether ◽  
Silyl Enol Ether

scholarly journals Bioinspired Divergent Oxidative Cyclization of Strictosidine and Vincoside Derivatives: Second Generation Enantioselective Total Synthesis of (–)-Cymoside

2020 ◽  
Author(s):  
Yingchao Dou ◽  
Cyrille Kouklovsky ◽  
Guillaume Vincent
Keyword(s):  
Total Synthesis ◽  
Second Generation ◽  
Oxidative Cyclization ◽  
Enol Ether ◽  
Enantioselective Total Synthesis ◽  
Terminal Alkene

<p>We report our second generation synthesis of (–)-cymoside as well as the formation of a new hexacyclic-fused furo[3,2-<i>b</i>]indoline framework. After a Pictet-Spengler condensation between secologanin tetraacetate and tryptamine, the course of the cyclization of the 7-hydroxyindolenine intermediate generated by oxidation with an oxaziridine, depends on the stereochemistry of the 3-position. The 3<i>-(S)-</i>strictosidine stereochemistry delivered efficiently the scaffold of cymoside via intramolecular coupling with the C16-C17 enol ether, while the 3<i>-(R)-</i>vincoside stereochemistry directed towards the reaction with the C18-C19 terminal alkene and the formation of the unexpected caged compound.</p>

scholarly journals Enantioselective Total Synthesis of (+)‐Garsubellin A

2021 ◽  
Author(s):  
Dongseok Jang ◽  
Minchul Choi ◽  
Jinglong Chen ◽  
Chulbom Lee
Keyword(s):  
Total Synthesis ◽  
Enantioselective Total Synthesis

Enantioselective Total Synthesis of ( – )‐Spiroxins A, C and D

2021 ◽  
Author(s):  
Xin Shu ◽  
Chong-Chong Chen ◽  
Tao Yu ◽  
Jiayi Yang ◽  
Xiangdong Hu
Keyword(s):  
Total Synthesis ◽  
Enantioselective Total Synthesis

Unified enantioselective total synthesis of 3,6-dioxygenated diketopiperazine natural products, diatretol and lepistamides A, B and C

2021 ◽  
Vol 67 ◽  
pp. 152895
Author(s):  
Shu Takahashi ◽  
Aoi Kimishima ◽  
Tomoyasu Hirose ◽  
Takeshi Yamada ◽  
Akihiro Sugawara ◽  
...  
Keyword(s):  
Natural Products ◽  
Total Synthesis ◽  
Enantioselective Total Synthesis

Enantioselective total synthesis of sesquiterpenoid phellilane L and its diastereomer

Tetrahedron ◽  
2021 ◽  
Vol 87 ◽  
pp. 132110
Author(s):  
Gullapalli Kumaraswamy ◽  
Vankudoth Ramesh ◽  
Swargam Vijaykumar
Keyword(s):  
Total Synthesis ◽  
Enantioselective Total Synthesis
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