scholarly journals Intramolecular Aminolactonization for Synthesis of Furoindolin-2-One

Molecules ◽  
2021 ◽  
Vol 27 (1) ◽  
pp. 102
Author(s):  
Kazuhiro Higuchi ◽  
Kazunori Matsumura ◽  
Takafumi Arai ◽  
Motoki Ito ◽  
Shigeo Sugiyama
Keyword(s):  
Natural Products ◽  
Stereoselective Synthesis ◽  
Product Yield ◽  
Oxidative Cyclization ◽  
The Other ◽  
Single Bond ◽  
Polycyclic Compounds ◽  
Ester Moiety ◽  
Trisubstituted Alkenes ◽  
Lapidilectine B

Propellanes are polycyclic compounds in which tricyclic systems share one carbon–carbon single bond. Propellane frameworks that consist of larger sized rings are found in a variety of natural products. As an approach to the stereoselective synthesis of the propellane framework, one of the efficient methods is forming several rings in a single operation. Lapidilectine B (1) is composed of a propellane framework and was synthesized through the oxidative cyclization of trisubstituted alkenes. When the alkene with an ester moiety was treated with N-iodosuccinimide (NIS), iodocyclization proceeded to give the cyclic carbamate. On the other hand, when PhI(OAc)2 was allowed to react in the carboxyl form, a furoindolin-2-one structure corresponding to the A-B-C ring of lapidilectine B (1) was produced. Furthermore, when Pd(OAc)2 catalyst was used for cyclization under oxidative conditions, the product yield was improved.

A regio- and stereoselective synthesis of trisubstituted alkenes via gold(i)-catalyzed hydrophosphoryloxylation of haloalkynes

2011 ◽  
Vol 47 (27) ◽  
pp. 7851 ◽  
Author(s):  
Bathoju Chandra Chary ◽  
Sunggak Kim ◽  
Doosup Shin ◽  
Phil Ho Lee
Keyword(s):  
Stereoselective Synthesis ◽  
Trisubstituted Alkenes

Oxidative cyclization for the synthesis of complex tetrahydrofuran-containing natural products

2013 ◽  
Vol 85 (6) ◽  
pp. 1175-1184 ◽  
Author(s):  
Robert D. C. Pullin ◽  
Radosław M. Lipiński ◽  
Timothy J. Donohoe
Keyword(s):  
Natural Products ◽  
Amino Acid ◽  
Functional Groups ◽  
Lewis Acid ◽  
Excitatory Amino Acid ◽  
Oxidative Cyclization ◽  
Annonaceous Acetogenins ◽  
Hydride Shift ◽  
Vicinal Diols ◽  
Shift Sequence

The osmium-catalyzed oxidative cyclization of vicinal diols onto proximal olefins to generate 2,5-cis-substituted tetrahydrofurans (THFs) has been exploited as the key step for the construction of several complex THF-containing natural products, namely, the annonaceous acetogenins cis-sylvaticin, sylvaticin, and the excitatory amino acid neo-dysiherbaine A. Recently modified conditions that employ a Lewis acid enable the cyclization to proceed under milder conditions, providing greater tolerance to acid-sensitive functional groups, as demonstrated in two of the syntheses. Flexibility for the construction of 2,5-trans-THFs was demonstrated in the synthesis of sylvaticin by utilization of an intramolecular hydride-shift sequence.

Stereoselective Synthesis of Natural Products Promoted by Titanocene(III)

2018 ◽  
pp. 31-71
Author(s):  
Natalia M. Padial ◽  
Esther Roldan-Molina ◽  
Antonio Rosales ◽  
Míriam Álvarez-Corral ◽  
Ignacio Rodríguez-García ◽  
...  
Keyword(s):  
Natural Products ◽  
Stereoselective Synthesis

Chemical Defense of Lupins. Mollusc-Repellent Properties of Quinolizidine Alkaloids

1984 ◽  
Vol 39 (6) ◽  
pp. 553-558 ◽  
Author(s):  
Michael Wink
Keyword(s):  
Natural Products ◽  
Lactuca Sativa ◽  
Helix Pomatia ◽  
Free Food ◽  
The Other ◽  
Quinolizidine Alkaloids ◽  
Feeding Response ◽  
Artificial Diets ◽  
Arion Rufus

Polyphagous molluscs such as Helix pomatia and Arion rufus generally do not feed on plants containing alkaloids. Of 19 species tested 10 species were totally avoided, the other 9 species were less attacked than Lactuca sativa, which was readily taken. Plants containing quinolizidine alkaloids were studied in detail. Those species with the α-pyridone alkaloids cytisine and N-methylcytisine were avoided to a higher extent than plants with lupanine as the major alkaloid. Since the repellency observed could be due to other natural products present in the plants besides the alkaloids, the feeding response of Helix pomatia was tested on artificial diets containing quinolizidine alkaloids in various concentrations as the only variable. If the snails had the choice they clearly preferred alkaloid-free food or a diet with only low alkaloid concen­trations. Half-maximal repellency of cytisine is less than 2 mᴍ, of sparteine 1-5 mᴍ, and of lupanine 1-8mᴍ. Since the in vivo concentrations of sparteine, cytisine, and lupanine are equal to or higher than the inhibitory concentrations required it is concluded that quinolizidine alkaloids constitute a potential antimolluscan principle of legumes.

Aryne-based strategy in the total synthesis of naturally occurring polycyclic compounds

2018 ◽  
Vol 47 (21) ◽  
pp. 8030-8056 ◽  
Author(s):  
Hiroshi Takikawa ◽  
Arata Nishii ◽  
Takahiro Sakai ◽  
Keisuke Suzuki
Keyword(s):  
Natural Products ◽  
Total Synthesis ◽  
Polycyclic Compounds ◽  
Total Syntheses ◽  
Naturally Occurring

This review has outlined the strategies and tactics of using arynes in the total syntheses of polycyclic natural products.

Recent results toward the stereoselective synthesis of biologically active natural products

2007 ◽  
Vol 79 (2) ◽  
pp. 163-172 ◽  
Author(s):  
Luiz C. Dias ◽  
Luciana G. de Oliveira ◽  
Paulo R. R. Meira
Keyword(s):  
Natural Products ◽  
Total Synthesis ◽  
Cell Cultures ◽  
Stereoselective Synthesis ◽  
Animal Cell ◽  
Biologically Active ◽  
Asymmetric Total Synthesis ◽  
Callystatin A ◽  
Animal Cell Cultures ◽  
Active Natural

This paper describes the convergent and stereocontrolled asymmetric total synthesis of (+)-crocacins C and D, potent inhibitors of animal cell cultures and several yeasts and fungi, and (-)-callystatin A, a potent antitumor polyketide.

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