The cyclization mechanism involves an intermediate nerolidyl diphosphate leading to a helminthogermacradienyl cation. Following a 1,3-hydride shift of the original 1-pro-S hydrogen of (2E,6E)-farnesyl diphosphate, cyclization and deprotonation gives (-)-δ-cadinene.
Hu, Y., Chou, W.K., Hopson, R. and Cane, D.E. Genome mining in Streptomyces clavuligerus: expression and biochemical characterization of two new cryptic sesquiterpene synthases. Chem. Biol.18 (2011) 32–37. [PMID: 21276937]