Scheme 1. Reagents and conditions: a) (COCl)₂, CH₂Cl₂; b) 5, Et₃N, CH₂Cl₂; c) POCl₃, CH₂Cl₂, reflux; d) (R,R)-8 (3 mol%), HCO₂H/NEt₃, DMF, rt; e) MeOCOCl, DIPEA, CH₂Cl₂, rt; f) Pd(OAc)2 (5 mol%), DavePhos 11 (10 mol%), KOAc (2 eq.), DMA, 130 °C; g) LiAlH₄, Et₂O, 0 °C.