Total synthesis of neosurugatoxin

Total synthesis of neosurugatoxin, having a strong affinity for nicotinic receptors, is described.     

Synthesis,chemical transformation,and application of isoxazole derivatives in the total chemical synthesis of natural compounds (review)

New data (1981–1988) on the production and chemical transformations of isoxazoles and 2-isoxazolines and the regio- and stereochemical aspects of the formation, modification, and cleavage of the heterocycle are examined. Advances and problems in the use of the isoxazole strategy for the synthesis of natural compounds and their analogs are discussed.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 4, pp. 435–453, April, 1989.     

Diastereomixture and racemate of myo-inositol derivatives, stronger organogelators than the corresponding homochiral isomers

Contrary to the usually accepted phenomena, an optically heterogeneous 1:1 diastereomixture of DS and LS and a racemate of LS and DR obtained, respectively, from a racemic myo-inositol derivative and (S)- and racemic O-acetylmandelic acid formed stronger organogels, especially with aromatic fluids, than those formed from homochiral isomers, DS and LS. One of the plausible reasons for the formation of the stronger diastereomeric gel is shown to be the complementary interaction of two diastereomers.     

Synthesis of a key intermediate for the total synthesis of pseudopteroxazole

A facile synthesis of a key intermediate for the total synthesis of anti-mycobacterial compound pseudopteroxazole is described employing an intramolecular Diels-Alder cyclization and an iodine-mediated oxidative aromatization step.     

Model experiments on surugatoxin synthesis. an approach in the construction of the pentacyclic ring system

Synthesis of the ethyl ester 2a of the debromo-aglycone of surugatoxin 1 has been achieved in 10 steps starting from readily available ethyl 2-(2-oxo-3-indolenyl)-3-oxo-4-phthalimidobutyrate 3.     

Intermediates for the synthesis of indole alkaloids. Synthesis of tetrahydrocarbazole derivatives

The synthesis of new precursors 8 and 15 for the synthesis of tetracyclic indole alkaloids were described. Many new intermediates 4‐7 and 9‐14 have also been synthesized.     

Synthesis of a key intermediate for the total synthesis of streptovaricin A

A key intermediate ($\text{3}$) for the total synthesis of streptovaricin A ($\text{1}$) is synthesized in its optically active form. Further elaboration of $\text{3}$ is also described.     

Synthesis of the Trypanosoma cruzi LPPG heptasaccharyl myo-inositol

Synthesis of the heptasaccharyl myo-inositol found in Trypanosoma cruzi lipopeptidophosphoglycan was accomplished using a convergent assembly of three building blocks. The target compound is the first complete 2-aminoethyl phosphonic acid substituted glycan related to the glycosylphosphatidylinositol anchor family to be synthesized. The order of assembly enables synthesis of phosphoinositol oligosaccharides related to other glycosylinositolphospholipids in Tr. cruzi, the protozoan parasite causing Chagas' disease, which is endemic in South America.     

Synthesis of 4-haloserotonin derivatives and synthesis of the toad alkaloid dehydrobufotenine

4-Chloro-, 4-bromo- and 4-iodoserotonin derivatives were synthesized from 4-halo-5-oxyindoles, themselves derived from coumarins. Synthesis of the 4-iodoserotonins involved conjugate addition of an allyl group to a 5-iodocoumarin, followed by conversion of the allyl group into an aminoethyl unit. One of the iodoserotonin derivatives was converted into the toad alkaloid dehydrobufotenine, which was isolated as its hydroiodide.     

Intermediates for the synthesis of tetracyclic indole alkaloids. Synthesis of 4-aminotetrahydrocarbazole derivatives

An efficient method for the synthesis of 4-aminotetrahydrocarbazole derivatives from 2,3-dihydrospiro-[1H-carbazole-1,2′-(1,3)-dithiolan]-4-(9H)-one 1 is described. The structure of compound 6 has been confirmed by X-ray structure analysis.     

Biomimetic cyclization of geraniol derivatives, a useful tool in the total synthesis of bioactive monocyclic terpenoids

This review is a detailed account of authors' work in the field of biomimetic cyclization of geraniol-like dienes. The very high regio- and enantioselectivity achieved made these elegant reactions a viable tool for the synthesis of monocyclic building blocks used in the synthesis of valued terpenoids, like the precious aroma and perfume constituents' ionones and irones.     

Ultrasound mediated green synthesis of rhodanine derivatives: Synthesis,chemical behavior,and antibacterial activity

A variety of rhodanine derivatives were synthesized via a three-component reaction of carbon disulfide, amines, and dialkyl acetylenedicarboxylate in polyethylene glycol under conventional stirring or ultrasound irradiation. The sonochemical-assisted procedure provides an improved and accelerated conversion when compared to the conventional reaction, with increased rate of reaction and quality of product obtained. The product formed, 2a, could be readily converted to bis-rhodanine under microwave conditions. Moreover, the pyranothiazoles 9a,b were prepared from the corresponding rhodanines 2a,b and malononitrile. Fifteen compounds were screened for their antibacterial activities against nine human, animal and plant pathogenic Gram-positive and Gram-negative bacteria using the agar well diffusion method. Out of these derivatives, compounds 2g and 2h were the most effective against all tested bacteria.     

Metalloid derivatives for oganic synthesis the preparation of urazole and thiourazole derivatives

Silicon isocyanates are introduced as versatile reagents for the mild and efficient conversion of hydrazines to urazole derivatives.     

Stereoselective total synthesis of C2-symmetric natural products pyrenophorol and its derivatives

Abstract

A stereoselective total synthesis of 16-membered C₂-symmetric macrodiolide Pyrenophorol, Tetrahydropyrenophorol and 4,4-diacetylpyrenophorol have been accomplished. The synthesis started from commercially available L-Aspartic acid and the key reactions involved are regioselective epoxide opening, CBS reduction, Pinnick oxidation and Mitsunobu dilactonization.     

Triterpenoid total synthesis. Synthesis and absolute configuration of mispyric acid

The first synthesis of mispyric acid (1), an inhibitor of DNA polymerase beta with a novel triterpene skeleton, was achieved by starting from isoprene (2), geraniol (6) and 1,5-dimethoxy-1,4-cyclohexadiene (14). The absolute configuration of the naturally occurring 1 was determined as 2S,4S.