Since the late 1950's when proton n. m. r. spectroscopy was first used in organic natural products studies the technique has increasingly con of this important area of chemistry. tributed to the rapid advancement Although the potential utility of 13C n. m. r. was recognized very early, essentially no application of 13C n. m. r. appeared in the literature prior to 1966 and 95% of the existing data are less than five years old. The initially slow growth had its cause in inadequate instrumentation, insufficient sensitivity being the main obstacle. This situation drastically changed with the advent and commercial availability of broadband ex citation and Fourier transform methods, giving natural-abundance 13C n. m. r. and its numerous chemical applications a tremendous impetus. Today BC spectra can be recorded on sample quantities down to the submilligram level, which until recently even withstood proton n. m. r. Paralleling the development of experimental techniques considerable progress has also been made on an understanding of spectral parameters, in particular their stereochemical implications on natural products. Although the large majority of data present up to now deals with known structures, an adequate basis now exists which allows the chemist to use the technique for tackling real problems on unknown molecules."

Since the late 1950's when proton n. m. r. spectroscopy was first used in organic natural products studies the technique has increasingly con of this important area of chemistry. tributed to the rapid advancement Although the potential utility of 13C n. m. r. was recognized very early, essentially no application of 13C n. m. r. appeared in the literature prior to 1966 and 95% of the existing data are less than five years old. The initially slow growth had its cause in inadequate instrumentation, insufficient sensitivity being the main obstacle. This situation drastically changed with the advent and commercial availability of broadband ex citation and Fourier transform methods, giving natural-abundance 13C n. m. r. and its numerous chemical applications a tremendous impetus. Today BC spectra can be recorded on sample quantities down to the submilligram level, which until recently even withstood proton n. m. r. Paralleling the development of experimental techniques considerable progress has also been made on an understanding of spectral parameters, in particular their stereochemical implications on natural products. Although the large majority of data present up to now deals with known structures, an adequate basis now exists which allows the chemist to use the technique for tackling real problems on unknown molecules."

Scent and Chemistry Odor impressions have cast a spell over mankind since the dim and distant past. But even today, we are -consciously or subconsciously- guided by our sense of smell and the chemistry behind it. The prominent fragrance chemists Gunther Ohloff, Wilhelm Pickenhagen and Philip Kraft convey the scientist, the perfumer, and the interested layman with a vivid and up-to-date picture of the chemistry of odorants and the research in odor perception. In this second thoroughly revised and updated edition they are joined by creative perfumer Fanny Grau, a rising master in this metier, who complements the scientific treatise by a concise introduction to the art of perfumery and its composition techniques. Besides this new chapter on the creative aspects of perfumery, the book details on the molecular basis of olfaction, olfactory characterization of perfumery materials, structure-odor relationships, the chemical synthesis of odorants, and the chemistry of essential oils and odorants from the animal kingdom, backed up by many perfume examples and historical aspects. It will serve as a thorough introductory text for everyone interested in the molecular world of odors.