Several steps in the biosynthetic route suggested for illudoid sesquiterpenes, were chemically realized. Studies in this and related fields, mainly carried out in the authors' laboratory, were discussed.
Currently β-lactams are receiving considerable attention from organic and medicinal chemists because of the widespread occurence of β-lactam antibiotics such as penicillins and cephalosporins. Furthermore, β-lactam ring has been known to show high chemical reactivity and ease of molecular rearrangement and therefore to be potential synthons of value. β-Lactams would be useful source of the CO-C-C-N synthon (by cleavage of 1-2 fission) and the C-C-CO-N- unit (by cleavage of 1-4 fission) for the preparation of several kinds of different heterocyclic compounds, such as pyrrolidone, piperidone, quinolone, and oxazole. The author wishes to describe an application of β-lactam and related compounds to different heterocyclic compounds.
The use of high performance organic pigments has been increased in such industries as coatings, printing inks, plastics, synthetic fibers and so on because of their excellent fastness properties. A growing concern on the health and the safety is prompting the use of these pigments in place of the inorganic pigments containing Pb, Cr and Cd in the last few years. A great number of organic pigments have been developed to fulfill the fastness properties and many pigments of excellents fastness have been put to practical uses to form a pigment class called high performance organic pigment. The recent trends in this pigment class are summerised with emphasis on the organic syntheses.
Ketene silyl acetals have been developed as new versatile reagents for organic synthesis. The reactions of ketene silyl acetal with acid halides, carbonyl compounds, Schiff bases, and heterocummulenes and summarized. Oxidative coupling, oxidation and Mannich reaction of these reagents, and, an application of Claisen-type rearrangement of these reagents to the total synthesis of natural products are also described.