tri-n-butyl-tin hydride in tetrahydrofuran 2.25 h; Ambient temperatureIrradiation;

<b>Multi-step reaction with 4 steps<br /> </b>1: 1.) pyridine, (F₃CSO₂)2O, 2.) t-BuOK / 1.) CH₂Cl₂, -23 deg C, 5 min, 2.) THF, -23 deg C, 30 min<br />2: 93 percent / 0.21M LiOH / tetrahydrofuran / 4 h / 10 &deg;C<br />3: 1.) isobutyl chloroformate, 4-methylmorpholine, 2.) pyridine / 1.) THF, -15 deg C, 5 min, 2.) THF, 20 min<br />4: 20 percent / tetrahydrofuran / 0.13 h / Ambient temperature; Irradiation<br /> <br /> &nbsp;