Application of Carbon-13 NMR spectroscopy to the chemistry of natural products

Carbon-13 NMR spectroscopy(abbreviated CMR) is an extremely powerful strategy for the study of natural organic molecules. The information derivable from CMR is often complementary to that obtianed form proton NMR spectroscopy (PMR). Because of low natural abundance of $^{13}C$ nucleus (1.1%) coupled with low inherent sensitivity relative to $^{1}H$ (about 1/64), CMR experiment is approximately 6000 times less sensitive than PMR. Despite of this, now it is possible to measure CMR of small amount of compound by the development of three significant ingenious techniques, i. e. a) computer time-averaging, b) wide-band (or noise modulated) proton decoupling, and c) pulsed Fourier transform (FT) NMR : For general recognition of CMR, its fundamental aspects of CMR are briefly reviewed.