Diels–Alder reaction
An unexpected addition that revealed a new class of reactions
Emil Fischer – that titan of organic chemistry and nailed-on favourite for the most appearances in a column about named reactions – was a man feared by his students. In the late 19th century, Fischer directed the teaching laboratories at Friedrich Wilhelms University in Berlin. In the course of one daily inspection in the winter of 1896, he descended upon a nervous undergraduate.
Usually known for his violent temper and critical judgement, Fischer was smiling. Perhaps he had seen something of the future in this young man. The student was confused by the turn of events and unable to answer questions related to the iron–aluminium separation in hand, but was not severely reprimanded. Given the advice that he should carry out experimental work only after careful study of its theoretical foundations in future, the 20-year-old Otto Diels would not forget his lesson.