scholarly journals Preparation of conjugated dienoates with Bestmann ylide: Towards the synthesis of zampanolide and dactylolide using a facile linchpin approach

2015 ◽  
Vol 11 ◽  
pp. 1815-1822 ◽  
Author(s):  
Jingjing Wang ◽  
Samuel Z Y Ting ◽  
Joanne E Harvey
Keyword(s):  
Natural Products ◽  
Allylic Alcohols ◽  
Secondary Alcohols ◽  
Unsaturated Aldehyde ◽  
Unsaturated Esters ◽  
Highly Efficient ◽  
Efficient Route

Bestmann ylide [(triphenylphosphoranylidene)ketene] acts as a chemical linchpin that links nucleophilic entities, such as alcohols or amines, with carbonyl moieties to produce unsaturated esters and amides, respectively. In this work, the formation of α,β,γ,δ-unsaturated esters (dienoates) is achieved through the coupling of Bestmann ylide, an alcohol and an α,β-unsaturated aldehyde. Primary and secondary alcohols, including allylic alcohols, are suitable substrates; the newly formed alkene has an E-geometry. Strategically, this represents a highly efficient route to unsaturated polyketide derivatives. A linchpin approach to the synthesis of a major fragment of the natural products zampanolide and dactylolide is investigated using Bestmann ylide to link the C16–C20 alcohol with the C3–C8 aldehyde fragment.

scholarly journals Highly Efficient Kinetic Resolution of Aryl-Alkenyl Alcohols by Ru-Catalyzed Hydrogen Transfer

Molecules ◽  
2021 ◽  
Vol 26 (24) ◽  
pp. 7475
Author(s):  
Yipeng You ◽  
Ming Yu Jin ◽  
Guanyu Tao ◽  
Xiangyou Xing
Keyword(s):  
Organic Synthesis ◽  
Hydrogen Transfer ◽  
Kinetic Resolution ◽  
Asymmetric Reduction ◽  
Building Blocks ◽  
Enantioselective Synthesis ◽  
Allylic Alcohols ◽  
Secondary Alcohols ◽  
Highly Efficient ◽  
Reduction Of Ketones

No matter through asymmetric reduction of ketones or kinetic resolution of secondary alcohols, enantioselective synthesis of the corresponding secondary alcohols is challenging when the two groups attached to the prochiral or chiral centers are spatially or electronically similar. For examples, dialkyl (sp3 vs. sp3), diaryl (sp2 vs. sp2), and aryl-alkenyl (sp2 vs. sp2) alcohols are difficult to produce with high enantioselectivities. By exploiting our recently developed Ru-catalysts of minimal stereogenicity, we reported herein a highly efficient kinetic resolution of aryl-alkenyl alcohols through hydrogen transfer. This method enabled such versatile chiral building blocks for organic synthesis as allylic alcohols, to be readily accessed with excellent enantiomeric excesses at practically useful conversions.

Application of Dess-Martin oxidation in total synthesis of natural products

2020 ◽  
Vol 17 ◽  
Author(s):  
Majid M. Heravi ◽  
Tayebe Momeni ◽  
Vahideh Zadsirjan ◽  
Leila Mohammadi
Keyword(s):  
Natural Products ◽  
Total Synthesis ◽  
Selective Oxidation ◽  
Secondary Alcohols ◽  
Aldehydes And Ketones

: Dess–Martin periodinane (DMP), is a commercially available chemical, frequently being utilized as a mild oxidative agent for the selective oxidation of primary and secondary alcohols to their corresponding aldehydes and ketones, respectively. DMP shows several merits over other common oxidative agent such as chromium- and DMSO-based oxidants, thus it is habitually employed in the total synthesis of natural products. In this review, we try to underscore the applications of DMP as an effective oxidant in an appropriate step (steps) in the multistep total synthesis of natural products.

Intramolecular Diels–Alder Reactions of Oxazoles, Imidazoles, and Thiazoles

Synthesis ◽  
2020 ◽  
Author(s):  
Peter Wipf ◽  
Thanh T. Nguyen
Keyword(s):  
Natural Products ◽  
Lewis Acid ◽  
Acid Catalysis ◽  
Copper Catalysts ◽  
Diels Alder ◽  
Synthetic Approach ◽  
Highly Efficient ◽  
Intramolecular Cycloadditions ◽  
Western Segment ◽  
Target Molecules

AbstractThe development of the intramolecular Diels–Alder cycloaddition­ of azole heterocycles, i.e. oxazoles (IMDAO), imidazoles (IMDAI), and thiazoles (IMDAT), has had a significant impact on the efficient preparation of heterocyclic intermediates and natural products. In particular, highly efficient and versatile IMDAO reactions have been utilized as a key step in several synthetic schemes to provide alkaloids and terpenoid target molecules. More limited studies have been performed on IMDAI and IMDAT cycloadditions. Some drawbacks, such as the occasionally­ challenging preparation of IMDA precursors, are also highlighted in this review. Perspectives are provided on how IMDAI and IMDAT­ transformations can be further expanded for target-directed syntheses.1 Introduction2 Oxazoles2.1 IMDAO Approaches to Furanosesquiterpenes and Furanosteroids2.1.1 Syntheses of Highly Oxygenated Sesquiterpenes2.1.2 Syntheses of (±)-Gnididione and (±)-Isognididione2.1.3 Synthesis of (±)-Stemoamide2.1.4 Synthesis of (±)-Paniculide A2.1.5 Syntheses of (+)- and (–)-Norsecurinine2.1.6 Synthesis of Evodone2.1.7 Syntheses of (±)-Ligularone and (±)-Petasalbine2.1.8 Syntheses of Imerubrine, Isoimerubrine, and Grandirubrine2.1.9 Syntheses of Furanosteroids2.1.10 Syntheses of Substituted Indolines and Tetrahydroquinolines2.2 IMDAO Approaches to Pyridines: the Kondrat’eva Reaction2.2.1 Syntheses of Suaveoline and Norsuaveoline2.2.2 Synthesis of Eupolauramine2.2.3 Syntheses of (–)-Plectrodorine and (+)-Oxerine2.2.4 Synthesis of Amphimedine2.2.5 Synthetic Approach to the Western Segment of Haplophytine2.2.6 Synthesis of Marinoquinoline A2.2.6.1 IMDAO Approach to Marinoquinoline A2.2.6.2 Scope of Allenyl IMDAO Cycloaddition2.3 Lewis Acid Catalysis in IMDAO Reactions2.3.1 Effects of Europium Catalysts on IMDAO Reactions2.3.2 Effects of Copper Catalysts on IMDAO Reactions3 Imidazoles 4 Thiazoles4.1 Syntheses of Menthane and Eremophilane4.2 Further Comments on the Intramolecular Cycloadditions of Thiocarbonyl Ylides5 Conclusions and Outlook

A Highly Efficient Conversion of Primary or Secondary Alcohols into Fluorides with n-Perfluorobutanesulfonyl Fluoride-Tetrabutylammonium Triphenyldifluorosilicate

Synlett ◽  
2009 ◽  
Vol 2009 (05) ◽  
pp. 779-782 ◽  
Author(s):  
Xueqing Zhao ◽  
Xiaowen Xue ◽  
Weiping Zhuang ◽  
Dongsheng Fang ◽  
Jingming Zhou
Keyword(s):  
Secondary Alcohols ◽  
Efficient Conversion ◽  
Highly Efficient

Direct-write printing of reactive oligomeric alkoxysilanes as an affordable and highly efficient route for promoting local adhesion of silver inks on polymer substrates

2016 ◽  
Vol 4 (11) ◽  
pp. 2211-2218 ◽  
Author(s):  
Marina N. Kirikova ◽  
Elena V. Agina ◽  
Alexander A. Bessonov ◽  
Alexey S. Sizov ◽  
Oleg V. Borshchev ◽  
...  
Keyword(s):  
Direct Write ◽  
Polymer Substrates ◽  
Highly Efficient ◽  
Novel Approach ◽  
Efficient Route ◽  
Polymeric Substrates

A novel approach for improving the printability and adhesion of silver inks on flexible and stretchable polymeric substrates is reported.

Ex‐Solved Ag Nanocatalysts on a Sr‐Free Parent Scaffold Authorize a Highly Efficient Route of Oxygen Reduction

2020 ◽  
Vol 30 (27) ◽  
pp. 2001326 ◽  
Author(s):  
Jun Hyuk Kim ◽  
Jun Kyu Kim ◽  
Han Gil Seo ◽  
Dae‐Kwang Lim ◽  
Seung Jin Jeong ◽  
...  
Keyword(s):  
Oxygen Reduction ◽  
Highly Efficient ◽  
Efficient Route
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