Fig. 2

Reagents and conditions: (a) appropriate leucinol, MeCN, rt, 3 h; (b) NaN3, EtOH, reflux. For the details see the main text below.
Reagents and conditions: (a) appropriate leucinol, MeCN, rt, 3 h; (b) NaN3, EtOH, reflux. For the details see the main text below.