aReagents and conditions: (A) (a) KOtBu, 1-bromododecane, CH2Cl2, reflux 20 h, 58%; (b) H2 (1 atm), Pd/C, EtOAc, 24 h, >99%; (c) triphosgene, pyridine, CH2Cl2, –78 °C to rt, 19 h, 70%. (B) (d) Triton B, acrylonitrile, CH2Cl2, rt, 18 h, >99%; (e) CoCl2·6H2O, NaBH4, MeOH, 0 °C, 1 h; (f) N,N′-Di-Boc-1H-pyrazole-1-carboxamidine, THF, 12 h, 75% over 2 steps; (g) lithium naphthalenide, THF, –25 °C, 3 h; (h) triphosgene, pyridine, CH2Cl2, –78 °C to rt, 3 h, 72% over 2 steps.