Asymmetric Total Synthesis of (2 R )-Hydroxynorneomajucin, a Norsesquiterpene from Illicium jiadifengpi .

We report the first total synthesis of (2 R )-hydroxynorneomajucin, a norsesquiterpene derived from the Illicium genus. This natural product displays neurotrophic properties. Small molecule neurotrophins have potential as therapeutics in neurodegenerative diseases. Key steps of our synthesis include a Tsuji-Trost reaction, a Pauson-Khand cyclization, and a Nagata hydrocyanation. A simple sequence of reductions and a Mukaiyama hydration introduce the A-ring substituents with the correct configurations. The overall synthesis was completed in 17 steps (longest linear sequence, LLS).