Reagents and conditions:
(a)
YbCl3, MeNO2, allyltrimethylsilane, 25 °C,
72 h, 73%; (b) O3, MeOH, −78 °C 1 h; NaBH4, −78 °C → 23 °C, 16 h, 62%; (c) pTsCl, TEA, 4-DMAP, MeCN, −5 °C → 25
°C, 16 h 80%; (d) 10, K3PO4, MeCN, 90 °C, 16 h, 94%; (e) KOH, [RhCl(COD)]2,
dioxane/water, 0 °C → 35 °C, 16 h, 97%; (f) LiAlH4, THF, 0 °C, 2 h, 93%; (g) NaOEt, dimethylmalonate, EtOH,
80 °C, 16 h; 52%; (h) HCl (conc) 120 °C, 16 h, 93%; (i)
B2H6, THF, 16 h, 57%.