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Research has been conducted on the natural biaryls, their precursors and unnatural analogs. The synthetic availability of these compounds allows to investigate their antiplasmoidal activities.

The singlet-oxygen ene reaction of chiral oxazolidine-substituted alkenes by remote urea NH is examined and compared with dimethyldioxirane and m-chloroperbenzoic acid epoxidations.

Research has been conducted on the enol carbonate, carbamate and ester radical cations. The characterization of these cations has been carried out via voltammetry and EPR spectroscopy and the results are presented.

Research has been conducted on hiochromanone- and thiochromone-type substrates' dioxirane oxidation. The chemoselectivity and diastereselectivity of oxygen transfer have been investigated.

Research details the synthesis of a chiral aryl-ferrocenylbidentate ligand via a modified 'lactone method' involving nickel(0)-assisted reductive C,C-coupling.

Stereoselective synthesis of sesquiterpene herbertenedios and its mastigophorines A nd B is described.

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.

Research was conducted to examine the effects of the addition of bromine to ketenes and bisketenes. The study of the kinetics and mechanism of ketene bromination is intended to demonstrate both electrophilic attack at C(sub a) and neighboring group participation by the second ketenyl group. Results demonstrate that the bromination of the ketene PhMe2SiCH=C=O resembles the second order in (Br2) bromination behavior of ordinary alkenes in halogenated hydrocarbon solvents.

A novel method for the synthesis of conformationally restricted polycyclic dihydropyrimidines (DHPs) was developed based on the utilization of omicron-alkenylaryl-tethered DHP-fused mesomeric betaines. The synthetic process was characterized by the intramolecular 1,3-dipolar cycloaddition reaction of the mesomeric betaine which led to the formation of the target compounds. The cycloaddition reaction was characterized by a reqioselective two-step annulation sequence which induced the formation of a rigid, polycyclic DHPs.

The directing effect of several heteroatom substituents on the diastereoselectivity of the singlet oxygen ene reaction in acyclic, cbiral olefins is investigated to ascertain its role in the diastereoselective singlet oxygen ene reaction. Results indicate pronounced steering effects on the diastereoselectivity of oxygen transfer processes such as photooxygenation and epoxidation. Such effects are valuable for the rational design of stereocontrolled oxyfunctionalizations in 1O2, mCPBA and dioxiranes.

The strategically sited hydroxy group on singlet oxygen induces the (4 + 2) cycloaddition of chiral naphthyl alcohols resulting in high diastereoselectivities. In nonpolar solvents, the photooxygenation of the alcohols leads to the formation of absolute configurated endoperoxides. Applying steric and electronic control the pi-facial selectivity is justified. The Peri strain is used to indicate the transition state energy of the respective conformers.

Decarboxylation of ester-functionalized beta-lactones formed in two-step sequence by adding ester and ketone enolates (Michael addition) to alpha-methylene beta-lactones followed by stereocontrolled decarboxylation of beta-lactones gives stereoselective synthesis of ester-functionalized olefins. This process utilizes the alpha-methylene beta-lactones as allene equivalents.

The photooxygenation of tricyclo(4.3.0.0-super 1,3)nona-6,8-dienes and bicyclo(4.3.0)nona-1(6),7-dienes (8 and 9) leads to two unstable endoperoxides with high diastereofacial selectivity. In the presence of triethylamine the endoperoxides undergo Kornblum-De La mare reaction to yield hydroxy enones. The endoperoxides undergo thermal rearrangement to give a series of products, and cyclooctene dione and cycloheptenone aldehyde respectively. The 8 and 9 dienes are produced by ring expansion of 3-methyl-1-phenyl-1,2-dihydropentalene.

Nitroxides are simple but effective substitutes for dioxygen in trapping triplet diradicals of the 1,3-cyclopentanediyl and trimethylenemethane type. Inthe photolysis of azoalkanes, the isoindolinyloxyl nitroxide traps the transient diradicals to produce bisalkoxyamines that are stable enough for isolation and characterization. The photochemical denitrogenation of a bis- azoalkane, using nitrogen and dioxygen traps, is also studied. The tetrakis- adduct yielded by the nitroxide is thermally unstable compared to the bis- peroxide produced by the dioxygen. The proposed reaction mechanism is loss of dinitrogen followed by trapping.

Control of diastereoselective and regioselective single-oxygen ene reaction of oxazolidine-substituted alkenes through hydrogen bonding is reported.

Research into the photochemical denitrogenation of azoalkanes is presented.

Issues concerning the study of the photocycloaddition of benzophenone to chiral allylic alcohols, to ascertain if it is hydroxy related, are discussed. Evidence is given that the regioselectivity of the process is due to hydrogen bonding and that diastereoselectivity also occurs, offering new applications for the Paterno-Buchi reaction.