1. Geometries of the newly synthesized seven - membered ring thionosulfites have been optimized by density functional theory ( DFT ).

2. Special methods for four - membered Carbocyclic rings are given in Chapter 32.

3. The progresses in five - membered heterocyclic metallocene analogic complexes and their application in olefin polymerization are reviewed.

4. This Paper has reviewed five - membered cyclic sulfate's synthesis and it's application for stereoselective synthesis.

5. Azole: a class of organic compounds having a five - membered heterocyclic ring with two double bonds.

6. This article reviews the ring opening reaction of five membered nitrogen containing heterocyclic compounds.

7. Proline is the only natural amino acid which contains an important five - membered secondarygroup.

8. Over the past four decades, many dearomatization reactions have developed and applied for synthesis of alicyclic compounds containing six- membered carboncyclic moieties.

9. Method Treatment of 8,9 anhydroerythromycin 6,9 hemiketal with iodine in the alkaline solution provided corresponding N monodemethylated 12 membered ring erythromycin derivative.