Intermediates
(i) 3 M NaOH, MeOH (95%), (ii) isobutylchloroformate (IBCF), triethylamine (TEA), tetrahydrofuran (THF), (iii) CH2N2/ether (92%), (iv) 4 M HCl/dioxane (83%), (v) 1.0 equiv 48% HBr (83%), (vi)