Scheme 21.

Synthesis of the 4'-C-phenyl thimidine analogues 189 and 190.

Reagents and Conditions: (i) 3-Benzyl-5-(2-hydroxyethyl)-4-methylthiazolium chloride, TEA, dioxane, 70–80 °C, 15 h, 71%; (ii) MeONa, MeOH, reflux, 40%; (iii) Ti(Oi-Pr)₄, (+)-diethyl tartrate, t-BuOOH, CH₂Cl₂, −20 °C, 114 h, 36% (ee 86%); (iv) BH₃.SMe₂, THF, 86%; (v) TBDMSCl, imidazole, CH₂Cl₂, 100%; (vi) DIBAL-H, toluene, 92%; (vii) Ac₂O, TEA, CH₂Cl₂, 90%; (viii) thymine, BSA, TMSOTf, CH₃CN, 88% (187:44%, 188:44%); (ix) TBAF, THF, 100%.