Recent advances in the syntheses of unusual organic molecules with unique chemical and physical properties, are reviewed. The more complex and unusual the substrate, the greater the danger of occurrence of unexpected or undesired reactions is. Therefore, crucial steps for preparing them are described in detail in connection with their chemical and physical properties.

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Recently, studies on the chiral synthesis have been extensively stressed upon. There has been progress in cooperation with the development of highly selective reagents. Useful enzymes (e. g. immobilized enzymes), microorganisms, and excellent analytical instruments for spectroscopy and for the chromatography have become available. In this context we reviewed the papers concerned with the syntheses of optically active compounds from the meso compounds and the symmetrical molecules having a prochiral carbon atom. We have dealt only with the compounds possessing functional groups in the same ligands of the symmetrical prochiral molecule.

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During these ten years, reactions which are carried out with the use of reagents adsorbed on alumina or silica gel have increasingly appeared and many compounds have become accessible in much simpler synthetic procedures. This new method for organic synthesis is based on the reasoning that high reactivity of reagents are reduced or adjusted by adsorption to produce high selectivity of the reagents toward substrates. In some cases nature of the reagents is completely changed by adsorption to result in appearance of new reactions. Use of silica gel as a mild and therefore selective acid catalyst for some condensation reactions is also important. Usually these reactions proceed selectively, cleanly, and give products in high yields. These newly developed reactions are reviewed, mainly from the standpoint of organic synthesis.

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Molecular-level preparations of solid catalysts developed with the aid of modern physical techniques are reviewed. This review has a particular emphasis on the recent advances in boundary between surface science and catalytic chemistry. Typical examples of successful design of catalyst surfaces, e. q. single crystals, alloys, supported bimetallic catalysts, attached metal oxide catalysts, etc., are described. The surface tailoring based on surface science has strategic advantages in synthesis of catalysts of the new generation.

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Organic trioxides have received increasing attention in recent years. They are metastable intermediates in low temperature oxidations and ozonation of organic compounds and biochemical oxygenations. This review presents recent studies on the chemistry and synthetic aspects of organic trioxides which include thermochemistry, stabilities, and preparations of organic trioxides, and the oxidation of organic compounds with trioxides. Many organic trioxides decompose to give singlet oxygen and some of them have been used as a chemical source for singlet oxygen. Some trioxides also act as oxygen transfer agents and oxidize many organic compounds at low temperature.

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Poly (ethylene carbonate), poly (propylene carbonate), and poly (ethylene propylene carbonate) were examined as to their biodegradability, permeability, and drug release characteristics.
Poly (ethylene carbonate) degraded but poly (propylene carbonate) did not in the peritoneal cavity of rats and the peritoneal cavity and subcutaneous tissue of guinea pigs. Mixtures of the two polymers degraded at a rate in proportion to poly (ethylene carbonate) content. Degradation rate in the peritoneal cavity was faster than that in subcutaneous tissue in guinea pigs.
Membranes free from pores were obtained from poly (ethylene carbonate). Permeability of drugs through them depended on lipophilicity indicating role of solubility of the drugs in the membrane material for permeation.
Release rate of tegafur from poly (ethylene carbonate) implants was faster than that from poly (propylene carbonate) implants. Blood level profiles were obtained after implantation of implants in rats.
Microspheres containing local anesthetics were prepared by a solvent evaporation process and effects of drug content and polymer on release profiles were examined in vitro. Duration of local anesthesia after administration of dibucaine microspheres in guinea pigs was demonstrated.

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Sulfonation reaction of hydrocarbons is an important unit process in the production of detergents, dyestuffs, medicines and ion-exchange resins.
In recent years, sulfur trioxide has been a main reagent commonly used for the direct introduction of the -SO₃H group, especially in the sulfonation of some aromatic compounds, olefins and fatty acid esters.
Sulfur trioxide could be used for a large scale production by the development of sulfonation apparatuses which were suitable for this reaction. Also by use of this reaction, the environmental problems occurred in the conventional methods by the formation of spent acid were solved.
Sulfoxidation process was taken to the production of paraffine sulfonic acid.

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