Scheme 1. Shair's synthesis of galanthamine-like molecules with high substitutional diversity. Reagents and conditions: (1) R¹OH, PPh₃, DIAD, THF, 0 °C (×2); (2) R²SH, 2,6-lutidine, nBuLi, THF, 0→40 °C; (3) (i) R³CHO, AcOH, MeOH–THF; (ii) NaBH₃CN, MeOH or R³COCl, 2,6-lutidine, CH₂Cl₂ or R³NCO, CH₂Cl₂; (4) R⁴NH₂, AcOH, MeOH–CH₂Cl₂.