Six-Membered Ring Spiranes: Carbocycles and Heterocycles with Oxygen

The data concerning the structure, synthesis and reactivity of six-membered ring spiranes exhibiting carbocycles and heterocycles with oxygen atoms are reviewed. The structural aspects are discussed using specific stereogenic elements and stereochemistry descriptors for spiranes with six-membered rings. The data are supported by high field NMR investigations and molecular structures obtained by X-ray diffractometry. The general procedures and access to spiranes with carbocycles and with heterocycles with oxygen are commented.