Photochemical reactions of organic compounds in the crystalline states are reviewed. These include photocyclodimerization, intramolecular hydrogen abstraction, photodecomposition, and photorearrangement. Photochemical reactions in frozen solutions, and experimental methods for solid state photoreactions are briefly described.
Recent progress of carbon-carbon bond formation via organotin compounds is described. These reactions can be devided roughly into two categories, that is, substitution of organic halides and addition of carbonyl compounds. Among the organotin compounds, allyl-, vinyl-, ethynyl-, and phenyl-trialkyltin are promising reagents.
Initially, a number of important or established synthetic pyrethroids containing the chrysanthemate moiety are introduced, and there are also described the relative insecticidal potencies of specific stereoisomers of the chrysanthemates resulting from acid stereochemistry. Recently, many studies on structure modification of the acid moiety of pyrethroid have disclosed a number of the most distinguished synthetic pyrethroids containing diversely modified acid moieties, which have been successfully developed as the most outstanding pyrethroid insecticides in the recent years. Since a majority of the chrysanthemates now have been reinforced on the insecticidal potency basis by the synthetic selection of useful stereoisomers, various relevant methods of synthesis are progressively reviewed on optical resolutions followed by racemizations, a stereoselective synthesis and/ or a synthesis by asymmetric induction of optically active chrysanthemic acids in close reference to the insecticidal activities of resultant stereoisomers. Relevant methods leading to all the fenvalerate stereoisomers and specific stereoisomer mixtures resulting from the chirality of the alcohol moiety are also described. Finally, some of specific advantages that are delivered by the stereoisomer selection are commented regarding the insecticidal performance aspects essentially linked with developmental potentials of the synthetic pyrethroids.
This article is concerned only with benzylic oxidations among numerous applications of quinones as oxidants and dehydrogenating agents, covering the literature until 1978/1979. Rather than giving an exhaustive listing of all applications of quinones, it is tried to give a fairly comprehensive summary of typical oxidation reactions. Obviously, high-potential quinones such as ortho-chloranil and 2, 3-dichloro-5, 6-dicyanobenzoquinone (DDQ) occupy a prominent place on the list of quinones used in benzylic oxidations.
We have developed new reactions utilizing sulfur-containing leaving groups and attempted to use them for the synthesis of the biologically active natural products. As shown in Fig. 1, their leaving mode is classified into two types. As the application of the type 1 reactions, conversion of thioethers into ethers, dethioacetalization, C-C bond formation at the β-position of. 3, 4-dimethoxy-E-β-nitrostyrene, protection of the double bond, synthesis of γ-ketosulfoxides, selective formation of sulfoxides and sulfones, and synthesis of α-oxodimethylacetals and ketals are described. As the application of the type 2 reactions, synthesis of ketenedithioacetals, synthesis of α-oxodimethylketals and α-diketones via bissulfenylation of-α-oxomethylenes, monitored reduction of carboxylic acids, synthesis of amides through monitored aminolysis, synthesis of macrolactams, and synthesis of macrocyclic spermidine alkaloids are described.
This article reviews some of recent applications of the Grignard reaction to synthesis of alcohols, ketones, aldehydes, acetals, carboxylic acides, esters, ethers, amino, compounds, organo sulfer compounds, vinyl compounds, acetylenic compounds, and organometalic compounds. A number of compounds produced by the Grignard reaction are very valuable and special intermediates or products in the field of pharmaceutical, perfume, and other fine or specialty chemicals. Synthesis of many optically active compounds by the reaction of sec-alkyl Grignard reagents with alkenyl halides using chiral phosphine-metal complexes as catalysts has been receiving great attention.
Synthetic applications of triiron dodecacarbonyl, Fe3 (CO)12, are described together with its preparation and properties. Treatment of olefinic compounds with Fe3 (CO)3 can lead to the isomerization of a particular double bond and other synthetically useful transformations through the formation of tricarbonyliron complexes. α, β-Unsaturated ketones and imines undergo various types of cyclodimerizations through the formation of heterodiene tricarbonyliron complexes upon treatment with Fe3 (CO)3. These cyclodimerizations afford four-, five -, and six-membered ring systems, depending on the structure of enones and imines. Polynuclear anionic carbonyliron complexes derived from Fe3 (CO)12 effectively reduce nitro, imino and aldehyde groups.