Herbert Waldmann

3.1 – Protecting Groups

There is hardly any area of preparative organic chemistry in which the proper use of protecting groups is not a prerequisite for the successful achievement of the goals aimed at. For this reason such blocking functions have been developed for nearly 100 years by numerous researchers from all disciplines of organic chemistry, and consequently solutions to the existing problems have been devised, making use of various synthetic transformations. It was Fischer who, among his many important contributions to chemistry, first realized that the application of protecting functions is often a necessity for a successful synthesis. Thus, he introduced the isopropylidene ketal in carbohydrate chemistry1 (see Section 3.1.3), and for the first time used both the chloroacetyl moiety and a urethane, namely the ethoxycarbonyl group, as