Aims of Natural Product Synthesis, Changes over Time

Aims of Natural Product Synthesis, Changes over Time 

The synthesis of natural products of ever increasing complexity has been a perennial task of preparative organic chemistry. However, over time, the motivation underlying this activity has changed in a characteristic manner. Up to the 1960s the synthesis of a natural product constituted the sole - and later on, the most important - proof of its structure. The reliability of such structural proof was not 100% - as can be seen from the structural assignment of patchouli-alcohol 1, a case in which the wrong structure has been proven by synthesis [1]. The correct structure was finally established by X-ray analysis [2]. 

As long as the aim of natural product synthesis was to prove the proposed constitution and configuration of a new natural product, it was mandatory to use only synthetic transformations which were fully established in terms of their scope and reliability. The result could otherwise have been considered as ambiguous. As a consequence, natural product synthesis had to rely on a rather restricted arsenal of established methods. The task of providing structural proof was taken over gradually in the period from 1930 to 1970 by X-ray crystal structure analysis and NMR-spectroscopy. At the same time natural product synthesis was freed from the confinement regarding the methods to be used [3]. There- 

Stereoselective Synthesis Editors Ottow, Schollkopf, Schulz Springer-Verlag Berlin Heidelberg 1994 

Natural product synthesis in the eighties thus became the testing ground for newly developed synthetic strategies and methods. In this manner, the situation 

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