Extended Data Figure 1. Synthesis of AM841 and AM11542.

Reagents and conditions: (a) CH₃I, NaH, DMF, 0 °C to room temperature, 2 h, 95%; (b) DIBAL-H, CH₂Cl₂, − 78 °C, 0.5 h, 87%; (c) Br⁻ P⁺Ph₃(CH₂)₅OPh, (Me₃Si)₂NK, THF, 0–10 °C, 30 min, then addition to 3, 0 °C to room temperature, 2 h, 96%; (d) H₂, 10% Pd/C, AcOEt, room temperature, 2.5 h, 89%; (e) BBr₃, CH₂Cl₂, −78 °C to room temperature, 6 h, 85%; (f) diacetates, p-TSA, CHCl₃, 0 °C to room temperature, 4 days, 64%; (g) TMSOTf, CH₂Cl₂/MeNO₂, 0 °C to room temperature, 3 h, 71%; (h) TBDMSCl, imidazole, DMAP, DMF, room temperature, 12 h, 85%; (i) Cl⁻ Ph³P⁺CH₂OMe, (Me₃Si)₂NK, THF, 0 °C to room temperature, 1 h, then addition to 9, 0 °C to room temperature, 1.5 h, 73%; (j) Cl₃CCOOH, CH₂Cl₂, room temperature, 50 min, 95%; (k) K₂CO₃, EtOH, room temperature, 3 h, 84%; (l) NaBH₄, EtOH, 0 °C, 30 min, 98%; (m) TBAF, THF, −40 °C, 30 min, 96%; (n) TMG-N₃, CHCl₃/MeNO₂, room temperature, 18 h, 84%; (o) PPh₃, CS₂, THF, room temperature, 10 h, 76%; (p) (+)-cis/trans-p-mentha-2,8-dien-1-ol, p-TSA, benzene, reflux 4 h, 65%.