1: 94 percent / Me3SiN3, molecular sieves 3A, SnCl4 / CH2Cl2 / 12 h / Ambient temperature 2: 1.) NaBH4, 2.) pyridine / 1.) CH2Cl2, MeOG, 10 min, 2.) room temperature, 2 h View Scheme

<b>Multi-step reaction with 3 steps<br /> </b>1: 4N aq. NaOH / ethanol / 24 h / 25 &deg;C<br />2: pyridine / CH₂Cl₂ / 25 &deg;C<br />3: acetonitrile / 4 h / 0 - 25 &deg;C<br /> <br /> &nbsp;