Individual Classes of Heterocycles

Five-membered tellurium-containing heterocycles, general review 86MI24. 

Electrochemical reduction of Se- and Te-heterocycles 90YGK553. Se-Heterocycles, complexing ability of 88UK778. 

Se-Heterocycles as precursors of selenoaldehydes 88YGK1149. Ring-opening of heteroaromatic anions derived from selenophene and tellurophene 87AHC(41)41. 

3-Anionic cycloaddition reactions of a,j8-unsaturated selenolates and tellurolates in the synthesis of selenophene, tellurophene, and 1,3,4-sele-nadiazine derivatives 87UK267. 

---

It is interesting that the retrosynthetic approach to heterocycles is not considered in monographs or review articles on the synthesis of individual classes of heterocyclic compounds. The examples that follow illustrate the retrosynthetic approach to the five- and six-membered heterocyclic structures often encountered in natural or synthetic biologically active compounds. Examples 7.2, 7.3, 7.6, 7.11 and 7.12 demonstrate syntheses of biologically active compounds developed to large-scale production by chemists at PLIVA Co. (Croatia). 

---