1: TsOH / methanol 2: PBr3, Py / diethyl ether View Scheme

1: TsOH / methanol 2: PBr3, Py / diethyl ether 3: (i) EtMgBr, THF, (ii) /BRN= 1840948/, CuCl, (iii) TsOH, MeOH 4: PBr3, Py / diethyl ether 5: (i) EtMgBr, Et2O, (ii) /BRN= 1841586/, CuCl 6: (i) H2, Lindlar catalyst, EtOH, (ii) /BRN= 102415/, MeOH, Et2O View Scheme

<b>Multi-step reaction with 3 steps<br /> </b>1.1: toluene-4-sulfonic acid / dichloromethane / 4.5 h / 0 - 5 &deg;C<br />1.2: 0.5 h<br />2.1: ethylmagnesium bromide / tetrahydrofuran / 0.5 h / 40 - 70 &deg;C / Inert atmosphere<br />2.2: 0.25 h / 10 &deg;C / Inert atmosphere<br />2.3: 12 h / 20 - 70 &deg;C / Inert atmosphere<br />3.1: sodium iodide; copper(l) iodide / N,N-dimethyl-formamide / 0.33 h / 0 - 5 &deg;C / Inert atmosphere<br />3.2: 19 h / Inert atmosphere<br /> <br /> &nbsp;

<b>Multi-step reaction with 2 steps<br /> </b>1.1: potassium hydroxide / tetrahydrofuran / 1 h / -5 - 0 &deg;C<br />2.1: sodium iodide; copper(l) iodide / N,N-dimethyl-formamide / 0.33 h / 0 - 5 &deg;C / Inert atmosphere<br />2.2: 19 h / Inert atmosphere<br /> <br /> &nbsp;