Sir Robert Robinson's Anthocyanin Period: 1922-1934-A Case Study of an Early Twentieth-Century Natural Products Synthesis

Sir Robert Robinson was one of the leading synthetic organic chemists of the twentieth century. His work in both theoretical chemistry and natural product synthesis was pioneering and led to his being awarded the Nobel Prize in chemistry in 1947. His specific accomplishments in terms of chemical structures synthesised and the introduction of new theoretical propositions represented major accomplishments in chemistry in the first half of the twentieth century. As he was one of the leading figures in the emerging field of natural product synthesis, it is a valuable exercise to examine his publication pattern as it pertained to a natural products synthesis project. This pattern manifested itself in the publication of a series of papers over several years, each focused on a specific family of natural products, with the publications first concentrating on simple precursor structures, but quickly moving on to full synthetic procedures for the targeted natural products. This was followed by an exhaustive study of the particular family of compounds. This paper reports one of Robinson's synthetic programmes, namely the synthesis of anthocyanins, which was carried out from 1922 to 1934 and resulted in the publication of forty-seven papers, including one on the first artificial synthesis of a flower pigment. This approach, as outlined in Robinson's publications, to tackling a complex synthetic challenge provides insight into the methodology of one of the leading natural product chemists of the first half of the twentieth century.