1: (all-E)-3,7,11,15,19,23,27,31,35,39-decamethyl-2,6,10,14,18,22,26,30,34,38-tetracontadecaenyl bromide With tri-n-butyl-tin hydride; lithium diisopropyl amide in tetrahydrofuran; hexane 2 h; 2: 2,3-Dimethoxy-5-methyl-1,4-benzoquinone With silver(l) oxide; boron trifluoride diethyl etherate in dichloromethane 2 h; Further stages.;

1: NaH / dimethylsulfoxide; tetrahydrofuran / Ambient temperature 2: 30percent KOH/MeOH / 0 °C 3: BF3*OEt2 / CCl4 / -15 °C 4: activated MnO2 / diethyl ether / 0 °C View Scheme