scholarly journals Kinetic Resolution in Transannular Morita-Baylis-Hillman Reaction: An Approximation to the Synthesis of Sesquiterpenes from Guaiane Family

Catalysts ◽  
2022 ◽  
Vol 12 (1) ◽  
pp. 67
Author(s):  
Raquel Mato ◽  
Rubén Manzano ◽  
Efraím Reyes ◽  
Liher Prieto ◽  
Uxue Uria ◽  
...  
Keyword(s):  
Total Synthesis ◽  
Kinetic Resolution ◽  
Core Structure ◽  
Formal Synthesis ◽  
The Core

An approximation to the synthesis of several sesquiterpenes from the Guaiane family is described in which the core structure was obtained through a transannular Morita-Baylis-Hillman reaction performed under kinetic resolution. Several manipulations of the obtained MBH adduct have been carried out directed towards the total synthesis of γ-Gurjunene, to the formal synthesis of Clavukerin A, to the synthesis of a non-natural isomer of isoguaiane and to the synthesis of an advanced intermediate in the total synthesis of Palustrol.

Stereoselective Access to the Core Structure of Macroline-Type Indole Alkaloids: Total Synthesis of Macroline and Alstomicine

2018 ◽  
Vol 20 (16) ◽  
pp. 4782-4786 ◽  
Author(s):  
Vilas D. Kadam ◽  
Sridhara Shanmukha Rao B. ◽  
S. K. Mahesh ◽  
Mithun Chakraborty ◽  
S. Phani Babu Vemulapalli ◽  
...  
Keyword(s):  
Total Synthesis ◽  
Indole Alkaloids ◽  
Core Structure ◽  
The Core

Total synthesis of the complex taxane diterpene canataxpropellane

Science ◽  
2020 ◽  
Vol 367 (6478) ◽  
pp. 676-681 ◽  
Author(s):  
Fabian Schneider ◽  
Konstantin Samarin ◽  
Simone Zanella ◽  
Tanja Gaich
Keyword(s):  
Total Synthesis ◽  
Anticancer Agent ◽  
Alder Reaction ◽  
Diels Alder ◽  
Core Structure ◽  
Natural Sources ◽  
The Core ◽  
Diels Alder Reaction ◽  
Cyclobutane Ring ◽  
Quaternary Carbons

Canataxpropellane belongs to the medicinally important taxane diterpene family. The most prominent congener, Taxol, is one of the most commonly used anticancer agent in clinics today. Canataxpropellane exhibits a taxane skeleton with three additional transannular C–C bonds, resulting in a total of six contiguous quaternary carbons, of which four are located on a cyclobutane ring. Unfortunately, isolation of canataxpropellane from natural sources is inefficient. Here, we report a total synthesis of (–)-canataxpropellane in 26 steps and 0.5% overall yield from a known intermediate corresponding to 29 steps from commercial material. The core structure of the (–)-canataxpropellane (2) was assembled in two steps using a Diels–Alder/ortho-alkene-arene photocycloaddition sequence. Enantioselectivity was introduced by designing chiral siloxanes to serve as auxiliaries in the Diels–Alder reaction.

scholarly journals A formal synthesis of Balgacyclamide A using solution phase fragments condensation.

2020 ◽  
Author(s):  
Sandip Radhakisan Ugale ◽  
Somnath S Gholap
Keyword(s):  
Amino Acids ◽  
Total Synthesis ◽  
Spectral Data ◽  
Microcystis Aeruginosa ◽  
Solution Phase ◽  
Formal Synthesis ◽  
H Nmr ◽  
The Core ◽  
C Nmr

Abstract: A formal total synthesis of Balgacyclamide A as an antimalarial cynobactin of Microcystis aeruginosa (EAWAG 251) has been described. The synthesis of titled cyclamide was accomplished by the solution phase fragment synthesis using protection, deprotection and macrocylization process. Four common amino acids such as d-alanine, l-threonine, l-valine and d-allo-isoleucine, has been used for the construction of Balgacyclamide A. Including, the oxazoline and thiazole are the core structures was successfully achieved by using Burgess reagent and Hantzsch methods. The overall yield of the synthesized balgacyclamide A was found to be 2.03%, also structure was confirmed by1H-NMR, 13C-NMR and HRMS spectral data.

Studies toward the total synthesis of the variolins: rapid entry to the core structure

2001 ◽  
Vol 42 (2) ◽  
pp. 311-313 ◽  
Author(s):  
Regan J Anderson ◽  
Jonathan C Morris
Keyword(s):  
Total Synthesis ◽  
Core Structure ◽  
The Core

Oxidative Kinetic Resolution of cis-Fused Tricyclic 1-Tetralone Derivatives by Guanidine–Bisurea Bifunctional Organocatalyst

Synlett ◽  
2017 ◽  
Vol 28 (11) ◽  
pp. 1305-1309 ◽  
Author(s):  
Minami Odagi ◽  
Kazuo Nagasawa ◽  
Keisuke Hosoya ◽  
Yoshiharu Yamamoto
Keyword(s):  
Kinetic Resolution ◽  
Cumene Hydroperoxide ◽  
Core Structure ◽  
Enantioselective Synthesis ◽  
The Core ◽  
Oxidative Kinetic Resolution

We present an enantioselective synthesis of cis-fused tricyclic 1-tetralones via oxidative kinetic resolution in the presence of cumene hydroperoxide (CHP) and guanidine–bisurea bifunctional organocatalyst. This reaction affords the corresponding α-hydroxylation products together with unreacted tetralones in good to high enantioselectivity, with s values as high as 42. The reaction was successfully applied for the synthesis of the core structure of a kainoid derivative, 4-(2-methoxyphenyl)-2-carboxy-3-pyrrolidineacetic acid (MFPA).

ChemInform Abstract: Studies Toward the Total Synthesis of the Variolins: Rapid Entry to the Core Structure.

ChemInform ◽  
2001 ◽  
Vol 32 (16) ◽  
pp. no-no
Author(s):  
Regan J. Anderson ◽  
Jonathan C. Morris
Keyword(s):  
Total Synthesis ◽  
Core Structure ◽  
The Core

Stereoselective construction of 5,11-methanomorphanthridine and 5,10b-phenanthridine structural frameworks: Total syntheses of (±)-pancracine, (±)-brunsvigine, (±)-maritidine, and (±)-crinine

2012 ◽  
Vol 84 (7) ◽  
pp. 1597-1619 ◽  
Author(s):  
Ganesh Pandey ◽  
Smita R. Gadre
Keyword(s):  
Total Synthesis ◽  
Core Structure ◽  
Biologically Active ◽  
Single Electron ◽  
Azomethine Ylide ◽  
Dipolar Cycloaddition ◽  
Total Syntheses ◽  
The Core ◽  
One Step

The core structure of the complex pentacyclic 5,11-methanomorphanthridine skeleton and the vicinal quaternary and tertiary stereocenters of the 5,10b-phenanthridine skeleton are constructed stereospecifically in one step employing intramolecular 1,3-dipolar cycloaddition of a nonstabilized azomethine ylide (AMY) generated by the sequential double desilylation of appropriate bis-trimethylsilylmethyl amines using Ag(I)F as a single-electron oxidant. The strategy is successfully applied for the total synthesis of biologically active alkaloids such as (±)-pancracine, (±)-brunsvigine, (±)-maritidine, and (±)-crinine.

Indexicality of Grammar: The Case of Japanese Transgender Speakers

2019 ◽  
Author(s):  
Hideko Abe
Keyword(s):  
Gender Identity ◽  
Gender Identity Disorder ◽  
Grammatical Gender ◽  
Core Structure ◽  
Subject Positions ◽  
Transgender Identity ◽  
The Core ◽  
History Of ◽  
History Of Scholarship ◽  
Grammatical Structures

This article discusses how the intersection of grammatical gender and social gender, entwined in the core structure of language, can be analyzed to understand the dynamic status of selfhood. After reviewing a history of scholarship that demonstrates this claim, the discussion analyzes the language practices of transgender individuals in Japan, where transgender identity is currently understood in terms of sei-dōitsusei-shōgai (gender identity disorder). Based on fieldwork conducted between 2011 and 2017, the analysis reveals how individuals identifying with sei-dōitsusei-shōgai negotiate subject positions by manipulating the specific indexical meanings attached to grammatical structures.

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