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This paper highlights ongoing efforts toward Erythrina alkaloids, himandrine, tetrodotoxin, and thiopeptide antibiotics such as nosiheptide and describes representative spinoffs in biomedicine that emanated from the author's research in synthetic organic chemistry. Key words: alkaloids, hypervalent iodine, kinase inhibitors, lipids, thiopeptide antibiotics. Cette article decrit des efforts en cours vers la synthese d'alcaloides d'Erythrina, de l'himandrine, de la tetrodotoxine et d'antibiotiques thiopeptidiques tels que le nosiheptide, ainsi que des retombes representatifs en biomedicine de la recherche de l'auteur en chimie organique de synthese. Mots-cles: alcaloides, iode hypervalent, inhibiteurs de la kinase, lipides, antibiotiques thiopeptidiques., Introduction This paper provides a summary of a lecture that the author presented at the May 2013 meeting of the Canadian Society for Chemistry (Quebec City, Quebec) as the recipient [...]

Exploratory work toward the alkaloid himandrine evaluated the directing ability of a pyrrolidine C-3 substituent in a diastereotopic group elective intramolecular Diels-Alder reaction of a spirodienone obtained by the oxidative amidation of a phenol. The study also defined a technique for the construction of ring D of the alkaloid. Key words: alkaloids, Diels-Alder, himandrine, hypervalent iodine, phenols. Des travaux preliminaires en vue de la synthese de l'alcalo'ide himandrine ont permis d'evaluer la possibility d'un substituant en position C-3 d'une pyrrolidine d'orienter la reaction dans un groupe selectif diastereotope, d'une reaction de Diels-Alder intramoleculaire d'une spirodienone obtenue par amidation oxydante d'un phenol. L'etude a aussi permis de definir une technique pour la formation du cycle D de l'alcalo'ide. Mots-cles: alcalo'ides, Diels-Alder, himandrine, iodure hypervalent, phenols. [Traduit par la Redaction], Introduction The architecturally interesting alkaloid himandrine (1) (1) invites the exploration of an approach that relies on a tandem oxidative amidation (2)--intramolecular Diels-Alder (IMDA) (3) reaction of phenolic sulfonamide 5. [...]

Research has been conducted on the decyanative aromatization under oxygen starvation. Results suggest that 3-cyano-2-pyridones or 3-unsubstituted-2-pyridones can be controlled by admitting or excluding O (sub)2 in the cause of the reaction.

The natural products FR901483 and TAN1251C exhibit a novel tricyclic azaspirane core, and their total synthesis is reported.

Research points out that the oxidative cyclization of phenolic omega-arylalkanoic carboxamides to spirolactams can be accomplished using iodobenzene diacetate via oxazoline intermediates. Results suggest that these transformations of the organic hypervalent iodine chemistry are useful in the syntheses of azaspirocyclic products.

We describe a total synthesis of ([+ or -])-chlorovulone II that is 10 steps shorter than the best alternative currently available (nine vs 19 steps). The key event of the synthesis is an aldol addition of the enolate of ethyl acetate into 4-cyclopentene-1,3-dione, a substance that has received little attention as an educt for prostanoid synthesis and for which little is known about carbonyl 1,2-addition with enolates. In addition, we provide chemical and stereochemical details of a route to a key intermediate toward the title compound that involves a carbonyl-ene reaction and a radical addition to an aldehyde carbonyl.

An unusual level of conformational rigidity can be seen in the N-acyl derivatives of piperazic acids, as they exist as single rotamers about the tertiary amide structure. Such preference may be attributed to electrostatic repulsion between the ring imino N atom and the carbonyl oxygen on the PCA N-2 acyl unit. Since calculations also indicate that N-2-acyl PCAs share a similarity in shape with N-acylprolines, they may be used as replacement for proline within peptides when a turn motif is desired.

The synthesis of (plus or minus)-phyllanthocin involved the enelike reaction of an aldehyde with 2-methoxypropene. The chemistry is suited to multistep synthetic applications and illustrates streocontrol in the creation of the phyllanthocin structure can be achieved though thermodynamic equilibration of peripheral sterogenic carbons.

The representative phenanthroizidine alkaloids, tylophorine and antofine, and their seco congeners, septicine and julandine, were fully synthesized from sterically congested 3,4-diarylpyridines produced by a modified Knoevenagel-Stobbe synthesis. The process took advantage of the ability of alpha-dicarbonyl enones to combine in a formal (4 + 2)-cycloaddition with sterically demanding vinyl ethers.

The preparation of sulfur-containing pyridoacridine alkaloids, dercitins, shermilamine B, kuanoniamines and diplamine, involves a common intermediate representing the cystodytins. The oxidative sulfenylation of the intermediate, cystodytin J, leads to diplamine. Thermophotolysis of an amide precursor gives shermilamine. Selective N-methylation of the pyridine ring fragment produces dercitin.

A singlet diradical mechanism may underlie quinone-olefin photocycloaddition reactions, regioselectivity and loss of olefin stereochemistry during benzoquinones-alkylidenecycloalkane reactions. These Paterno-Buchi reactions exhibit regioselective behavior, induced by olefin ring-size and substate conformational properties. The collapse of a charge-transfer character exciplex leads to oxetane formation.