Ruzicka's biogenetic isoprene rule (1921, formalised 1953): all terpenes are biosynthesised by head-to-tail coupling of C₅ isoprene units (2-methyl-1,3-butadiene carbon skeleton), so their carbon counts are exact integer multiples of 5. …
Ruzicka's biogenetic isoprene rule (1921, formalised 1953): all terpenes are biosynthesised by head-to-tail coupling of C₅ isoprene units (2-methyl-1,3-butadiene carbon skeleton), so their carbon counts are exact integer multiples of 5. …