Martin Jaeger, Ruud L.E.G Aspers.
Steroids and NMR, Annual Reports on NMR SpectroscopyIn this chapter, the NMR spectroscopic investigation of steroids is analyzed from five different angles, yet the general stage, the steroid-specific aspect and the provision of an illustrative example are the common themes for each perspective. Firstly, steroids and NMR are placed in their chemical, analytical and pharmaceutical context. Secondly, the characteristic challenges of steroid structure elucidation and the aspects of specific moieties of steroidal compounds are described following chronological and also stereospecific lines. Subsequently, the application of NMR methodology is reviewed with respect to host–guest chemistry, impurity profiling and isotopic labelling, such as 3H, 17O and 19F. Furthermore, the use of computer-assisted structure elucidation applied to the steroids using incremental systems, simple databases and the current sophisticated spectral prediction algorithms will be discussed and their applications compared for testosterone and tibolone. The most recently developed and also the rare, but nonetheless valuable, NMR methods will also be presented. These include covariance processing, residual dipolar couplings and high-sensitivity CC INADEQUATE experiments.
Tibolone is used as the common thread and serves as an illustrative example throughout this chapter.