Synthesis of Natural Compounds

Reactions of sulfonic acid A-sodium A-chloroamides with heterocycles in organic synthesis, in particular in synthesis of natural compounds 99ZOR503. 

Synthesis of natural compounds by intramolecular attack of N-nucleophile on electrophilic center 99CSR61. 

This strategy is very useful for the synthesis of natural compounds and their analogs. Let us consider this approach in more detail using sequence I (Chart 3.18) as an example. 

His research interests deal with the chemistry of cyclopropane derivatives, 1,3-dipolar cycloadditions, synthesis of natural compounds and biologically active analogues. Recently, the research activity is also dedicated to synthetic studies for the production of new materials light-harvesting antenna systems and functionalized organogelators. 

If the reaction is carried out in the presence of solid base (K2CO3), a loss of radioactive ketone product takes place due to absorption on the base. The method has been successfully applied in the synthesis of natural compounds, for example, grossularines (Equation (19)). ... 

The aim of this review is to survey the advances in the chemistry of chrom-3-enes (2 -l-benzopyratis, chroin-/l3-eiies, a-chromenes)1 in the last decade. This subject was previously summarized by Wawzonek2 in 1951. A brief but clear treatment of chrom-3-ene chemistry can be found in Dean s book3 (1963), where a detailed account is given of all the natural products known at that time. A section of a recent book on the synthesis of natural compounds has been dedicated to chromenes.4... 

Despite increasing acceptance by scientists, some people viewed the synthesis of natural compounds as unnatural. Indeed proponents of the vital force theory can still be found on a quick scan of the Internet more than 100 years after it was discredited as a scientific theory. For example, vestiges of the vital force theory linger in the belief that vitamins from natural sources are somehow healthier than vitamins that are synthesized. 

As shown in Schemes 4.23 and 4.24, the bicydo[2.2.2]oct-5-en-2-ones gave the tricydo[3.3.0.02,8]oct-3-ones via ODPM rearrangements. The tricyclo[3.3.0.02,8]oct-3-ones are important key precursors for natural compounds such as polyquinanes. Hence, ODPM rearrangement has a high synthetic potential, and many chemists have utilized this as a key reaction in the syntheses of natural and non-natural compounds. Some recent reports of the synthesis of natural compounds are outlined at this point. 

Progress in the total synthesis of natural compounds 89GSM(11)612 90GSM(12)486 91GSM(13)430 92GSM(14)411 93GSM(15)356. 

The special potential for constructing double bonds stereoselectively, often necessary in natural material syntheses, makes the Wittig reaction a valuable alternative compared to partial hydrogenation of acetylenes. It is used in the synthesis of carotenoids, fragrance and aroma compounds, terpenes, steroides, hormones, prostaglandins, pheromones, fatty acid derivatives, plant substances, and a variety of other olefinic naturally occurring compounds. Because of the considerable volume of this topic we would like to consider only selected paths of the synthesis of natural compounds in the following sections and to restrict it to reactions of phosphoranes (ylides) only. 

Lead tetraacetate has shown its usefulness in the total synthesis of natural compounds. In a paper describing the preparation of several bioactive biphenyls such as magistophorenes... 

The universal applicability of acetylene as this type of bipolar synthon and its efficiency in the synthesis of natural compounds has already been demonstrated (Section 2.3.3.). 

In the field of homogeneous catalysis the metathesis of unsaturated hydrocarbons offers many intriguing possibilities for producing important intermediates and end products from alkenes and alkynes. Through major advances in catalyst design in recent years, metathesis has become an important synthetic route to be considered in chemical laboratories whenever a special organic product has to be obtained. In fine chemistry metathesis is a very valuable reaction for the synthesis of natural compounds. Metathetical polymerization has been accepted by the industry as a viable means for producing polymers. 

Prilezhaeva, E. N. Rearrangements of sulfoxides and sulfones in the total synthesis of natural compounds. Russian Chemical Reviews 2001,70, 897-920. 

O. S. Chizhov, Uglevody v Sinteze Prirodnykh Soedinenii (Carbohydrates in Synthesis of Natural Compounds). Nauka, Moscow, 1984. 

H7. Hems, B. A., Adrenocortical steroids (synthesis of natural compounds and some analogues). Brit. Med. Bull. 18, 93-98 (1962). 

Reactions of 1,3-dipolar cycloaddition of nitrile oxides in synthesis of natural compounds and their analogs 01UK730. 

Rearrangements of sulfoxides and sulfones in total synthesis of natural compounds 01UK1013. 

Survey of the most important achievements of the twenty century in the field of total synthesis of natural compounds 00AG(E)44. 

Bykov, V. I. and Finkelshtein, E.Sh. (1998) Synthesis of natural compounds via the cycloolefin cometathesis with a-olefins. J. Mol Catal A Chemical 133, 17-27. 

Development of Stetter reaction, particularly, in the synthesis of natural compounds 06CJ0906. 

Although these examples illustrate opportunities for using a variety of immobilized reagents for individual transformations, a more imaginative use of these methods is in multistep syntheses. In this respect our group s approach has been to minimize the use of conventional workup procedures, yet be able to prepare complex natural products and related compounds simply and efficiently. In this chapter we refrain from commenting on the use of on-bead synthesis of natural compounds or on the diversity-oriented procedures. 

N. K.Kochetkov, A.F.Sviridov, H.S.Ermolenko, et al., "Carbohydrates in the Synthesis of Natural Compounds",(Nauka Moscow, USSR), 1984. 

---