Cyclooctyne and 4-cyclooctyn-1-ol -: Versatile building blocks in organic synthesis

The readily available and highly reactive title compounds represent versatile building blocks in organic synthesis. Recent examples of 1,3-dipolar cycloadditions and Diels-Alder reactions and their applications are described. This microreview is especially devoted to cycloadducts formed between 1 and 2 and furans, and their transformations to give a variety of different classes of compounds, including derivatives of natural products. Here the conversion of oxanorbornadienes into bridged oxepines plays an important role in many cases. Different routes to enantiomerically pure compounds are also presented. (c) Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2005.