Scheme 1.

Synthetic routes to compounds 5, 8, 10 and 12. Reagents and Conditions: (a) NaH, DME, 4-MeBnBr, RT-60 °C; 63%; (b) n-BuLi, DME, (R)-phenyloxirane, RT- 90 °C; 11%–20% (c) t-BuOK, THF, 0 °C–RT; 86%; (d) (CH₃)₃SOI, NaH, DMSO; 0 °C–RT; 54%; (e) LiOH, THF/MeOH/H₂O, 100 °C; 50–60%; (f) TES, Pd/C, MeOH, RT; 100%; (g) NH₂CH(CH₃)₂, RT; 55%;