1: diethyl ether 2: sodium hydride / tetrahydrofuran 3: 2,2'-azo-bisisobutyronitrile; tri-n-butyl-tin hydride / toluene 4: dichloro bis(acetonitrile) palladium(II); oxygen; copper(l) chloride / water; N,N-dimethyl-formamide View Scheme

1: 38 percent / piperidine / acetonitrile / Ambient temperature 2: DIBAL-H / toluene; tetrahydrofuran / 0 °C 3: BuLi / tetrahydrofuran / 0 - 20 °C 4: 40percent aq. HF / Ambient temperature 5: 85 percent / (COCl)2, DMSO / CH2Cl2 / 0.25 h / -70 °C 6: 67 percent / (i-PrO)3P / (dba)3Pd2*CHCl3 / tetrahydrofuran / 2 h / Ambient temperature View Scheme

1: 38 percent / piperidine / acetonitrile / Ambient temperature 2: DIBAL-H / toluene; tetrahydrofuran / 0 °C 3: BuLi / tetrahydrofuran / 0 - 20 °C 4: 40percent aq. HF / Ambient temperature 5: 60 percent / (i-PrO)3P / (dba)3Pd2*CHCl3 / tetrahydrofuran / 16 h / Ambient temperature View Scheme