... Journal of the ... J. Am ... a Reagents and conditions: (a) 36, 0.5 equiv of PBu 3 , MeCN, 51%; (b) DMAP, Et 3 N, BOC 2 O, CH 2 Cl 2 , 90%; (c) 5 equiv of LiCl, 1.5 equiv of H 2 O, HMPA, 100 °C, 66%; (d) 3.0 equiv of n-Bu 4 NF, THF, 79%; (e) 1.9 equiv of LiCl, 4.0 equiv of collidine, 4.0 ...