1: 66 percent / NaOMe, MeOH / tetrahydrofuran / 5 °C 2: 55 percent / xylene / Heating 3: 80 percent / sodium cyanoborohydride / acetic acid 4: 70 percent / DIBAL / toluene / -70 °C 5: 51 percent / Ph2P(CH3)2PPh2 / (Ph3P)Rh(CO)Cl / xylene / Heating View Scheme

Multi-step reaction with 2 steps 1: KOt-Bu / tetrahydrofuran2: aq. HCl, CH2Cl2  

Multi-step reaction with 3 steps 1: 66 percent / NaOMe, MeOH / tetrahydrofuran / 5 °C2: 55 percent / xylene / Heating3: sodium cyanoborohydride / acetic acid  

Multi-step reaction with 2 steps 1: 66 percent / NaOMe, MeOH / tetrahydrofuran / 5 °C2: 55 percent / xylene / Heating