scholarly journals Rapid, two-pot procedure for the synthesis of dihydropyridinones; total synthesis of aza-goniothalamin

2020 ◽  
Vol 16 ◽  
pp. 135-139
Author(s):  
Thomas J Cogswell ◽  
Craig S Donald ◽  
Rodolfo Marquez

A fast, protecting-group-free synthesis of dihydropyridinones has been developed. Starting from commercially available aldehydes, a novel one-pot amidoallylation gave access to diene compounds in good yields. Ring-closing metathesis conditions were then employed to produce the target dihydropyridinones efficiently and in high yields.

2016 ◽  
Vol 14 (38) ◽  
pp. 9072-9079 ◽  
Author(s):  
Rupesh A. Kunkalkar ◽  
Debasish Laha ◽  
Rodney A. Fernandes

A de novo protecting-group-free total synthesis of (+)-muricadienin, (+)-ancepsenolide and (+)-3-hexadecyl-5-methylfuran-2(5H)-one has been achieved by ring-closing-metathesis and sp–sp3 Sonogashira type coupling.


2016 ◽  
Vol 35 (1) ◽  
pp. 45
Author(s):  
Naoufel Ben Hamadi ◽  
Ahlem Guesmi ◽  
Wided Nouira

Cycloaddition of the diazoalkanes to electron-deficient olefins (in situ) affords polysubstituted cyclopropanes in high yields (up to 85%). Deprotection of the ketal protecting group provided water-soluble cyclopropane-bearing carbohydrate in good yields. Antimicrobial activity screening of the synthesized compounds 8 and 9, utilizing a variety of Gram-positive (Staphylococcus aureus and Enterococcus fecalis), Gram-negative bacteria (Escherichia coli and Klebsiella pneumoniae) and yeast (Candida albicans), exhibited that all the prepared analogues acquire promising activities against both Gram-positive and Gram-negative bacteria especially compounds 9b and 9c (antimicrobial active agents against Gram-negative bacteria).


Synlett ◽  
2022 ◽  
Author(s):  
Yang Liu ◽  
Ziyang Zhao ◽  
Chao Hu ◽  
Chuanfang Zhao ◽  
Jun Liu ◽  
...  

An efficient stereoselective synthesis of brevipolide M was established in 13 linear steps and 17.8% overall yields base on chiron approach. The key steps of our synthesis involved tandem homologation / tetrahydrofuran cyclization and sequential ring-closing metathesis (RCM) / double-bond migration in one-pot processes.


Synthesis ◽  
2021 ◽  
Author(s):  
Adisak Thanetchaiyakup ◽  
Hassayaporn Rattanarat ◽  
Sudaporn Aree ◽  
Tanwawan Duangthongyou ◽  
Tanin Nanok ◽  
...  

Melotenine A, isolated from Melodinus tenuicaudatus, possesses significant anticancer activity against several human cancer cell lines. The synthesis of (±)-melotenine A was achieved without the use of any protecting groups in 11 steps with an overall yield of 7%. The key steps of our strategy were the Diels–Alder reaction to construct the tetracyclic framework and ring-closing metathesis to form the seven-membered ring of (±)-melotenine A.


2019 ◽  
Vol 25 (1) ◽  
pp. 157-161 ◽  
Author(s):  
Shin-taro Katayama ◽  
Hiroshi Nishino

AbstractSpiro[cyclohexane-1,3’-indoline]-2,2’-diones were easily prepared in good to high yields by the oxidation of N-aryl-N-methyl-2-oxocyclohexane-1-carboxamides in one pot with a short reaction time. The spiroindolinediones could be important for the total synthesis of natural products.


Molecules ◽  
2020 ◽  
Vol 25 (2) ◽  
pp. 414 ◽  
Author(s):  
Andrea Calcaterra ◽  
Laura Mangiardi ◽  
Giuliano Delle Monache ◽  
Deborah Quaglio ◽  
Silvia Balducci ◽  
...  

The Pictet-Spengler reaction (P-S) is one of the most direct, efficient, and variable synthetic method for the construction of privileged pharmacophores such as tetrahydro-isoquinolines (THIQs), tetrahydro-β-carbolines (THBCs), and polyheterocyclic frameworks. In the lustro (five-year period) following its centenary birthday, the P-S reaction did not exit the stage but it came up again on limelight with new features. This review focuses on the interesting results achieved in this period (2011–2015), analyzing the versatility of this reaction. Classic P-S was reported in the total synthesis of complex alkaloids, in combination with chiral catalysts as well as for the generation of libraries of compounds in medicinal chemistry. The P-S has been used also in tandem reactions, with the sequences including ring closing metathesis, isomerization, Michael addition, and Gold- or Brønsted acid-catalyzed N-acyliminium cyclization. Moreover, the combination of P-S reaction with Ugi multicomponent reaction has been exploited for the construction of highly complex polycyclic architectures in few steps and high yields. The P-S reaction has also been successfully employed in solid-phase synthesis, affording products with different structures, including peptidomimetics, synthetic heterocycles, and natural compounds. Finally, the enzymatic version of P-S has been reported for biosynthesis, biotransformations, and bioconjugations.


2001 ◽  
Vol 79 (11) ◽  
pp. 1668-1680 ◽  
Author(s):  
Darren J Dixon ◽  
Alison C Foster ◽  
Steven V Ley

The total syntheses of the polyhydroxylated macrolactone (+)-aspicilin and a diastereoisomer have been achieved via a concise route, starting from the spatially desymmetrized (R',R',R,S)-2,3-butanediacetal-protected butane tetrol 13. The key steps include a regioselective silyl protection of 13 and a stereoselective Lewis acid mediated addition of allyltributylstannane to the equatorially disposed aldehyde of 4. Macrocyclization is achieved using ring closing metathesis, after which selective hydrogenation and protecting group removal yields the natural product.Key words: aspicilin, butanediacetal, desymmetrization, macrolactone, metathesis.


2018 ◽  
Vol 96 (2) ◽  
pp. 144-147 ◽  
Author(s):  
Michael Meanwell ◽  
Mathew Sutherland ◽  
Robert Britton

A short enantioselective total synthesis of 1-deoxygalactonojirimycin (migalastat) has been achieved that does not rely on chiral pool starting materials or biocatalysis. Instead, this synthesis exploits a one-pot proline-catalyzed α-chlorination and aldol reaction of a commercially available aldehyde to assemble the entire carbon skeleton in a single step. The key role played by a nitrogen protecting group in the final epoxide opening reaction is highlighted as is the amenability to access structural analogues using this route.


2007 ◽  
Vol 48 (14) ◽  
pp. 2621-2625 ◽  
Author(s):  
Debendra K. Mohapatra ◽  
Dhondi K. Ramesh ◽  
Michael A. Giardello ◽  
Mukund S. Chorghade ◽  
Mukund K. Gurjar ◽  
...  

2003 ◽  
Vol 56 (6) ◽  
pp. 585 ◽  
Author(s):  
Martin G. Banwell ◽  
Mark J. Coster ◽  
Alison J. Edwards ◽  
Ochitha P. Karunaratne ◽  
Jason A. Smith ◽  
...  

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).


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