This essay deals with the details of the discovery of the Michael addition reaction, focusing on Arthur Michael, an American chemist, after whom it is named. Michael envisaged the possibility of an addition reaction of sodiomalonate ester or sodioacetoacetate ester to α,β-unsaturated acid esters and confirmed this by experimentation. Some instances of IntroductionThe Michael reaction, [1][2][3] addition of stabilized anions (e.g., enolate) to α,β-unsaturated carbonyl and related compounds, is a prototype for the conjugate addition reactions of various nucleophiles [4,5] that now find wide utility in organic syntheses (Scheme 1).The reaction is named after the American chemist Arthur Michael (1853Michael ( -1942, who was peculiar in both his career and research activity. Details about his career, achievements, and personality may be gleaned from his memoirs, [6] biographical articles, [7] and essays on his works. [8][9][10] None of these, however, provides sufficient background on the chemistry, both specific to Michael's work and state of the art at the time, his motives, and the course of events leading to his crucial findings. Moreover, his role in the discovery and the generalization of the Michael reaction is not always described correctly. It is the aim of this essay, therefore, to bridge these lacunae and to establish Michael's crucial role. Stumble in Youth and Studying AbroadArthur Michael (Figure 1) was born in Buffalo, New York, on August 7, 1853 to a well-off real-estate investor.[10][a] Osaka City University, "My next analysis was copper pyrites, then rhyolite (a rock), chrome ion and triphiline (a mineral phosphate). This last was suggested to me by Arthur Michael, who proposed we should do it together, so we started at the same time. He spoilt his work so often that he had to begin again seven times, but worked so fast that he got a good result at the same time that I plodded to the end of my single analysis."To conclude his studies in Europe, Michael spent an additional year working with Adolphe Wurtz in Paris and Demitrij I. Mendeleev in St. Petersburg, and then, in 1880, he returned to America. He became an assistant in the chemical laboratory at Tufts College and then, after a short period, was promoted to a professor of chemistry. He devoted himself to teaching and training his students as well as to his own research, successfully overcoming the disadvantages of working at a small institution. Michael made great use of his ample knowledge and experience he obtained in Europe, and even used his own money to cover research expenditures. In 1887, Michael first reported on the reaction that bears his name. Evolving Research ActivityMichael's early work, which began after his return to Hofmann's laboratory, seemed to be focused on various separate problems in preparative and structural organic chemistry. Among his noteworthy achievements was the first synthesis of natural phenol glucosides (helicine, salicin, methylarbutin, etc.), [12] work that began during his stay in Paris. Chloroacetoglucose, th...

Stereoselective construction of contiguous stereogenic centers in the decalin ring -usually four -is central to the synthesis of clerodane diterpenoids and the present review surveys the methods utilized to meet this task. Major strategies for the stereocontrol are: (i) diastereoface-selective reactions on a rigid ring, (ii) conformational preference of a rigid ring structure in an equilibrium condition, and (iii) diastereoselective cyclization. According to the classification based on the methods for construction of the stereogenic centers, an overview will be presented to various synthetic studies on clerodane and related natural products, which are of current interest in view of biological activity. Use of Oxy-Cope Reactions 6.2 Use of Stereocontrolled Ring-Closure Reactions 7Concluding Remarks

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Three new diterpenoids have been isolated from the brown seaweed Dictyota linearis, and their structures determined by 1H and 13C NMR spectroscopy.

The structure of yahazunol, an antimicrobial substance isolated from the brown seaweed D. undulata Okamura, was established on the basis of spectral and chemical evidence.