1: 95 percent / sodium hydride / tetrahydrofuran / 1.) 0 deg C, 1 h, 2.) 23 deg C, 24 h 2: 1.) Et3N, 2.) K2CO3 / 1.) a) 0 deg C, 1 h, b) 23 deg C, 3 d, 2.) aq. EtOH, reflux, 20 h View Scheme

Yield given. Multistep reaction;

1: 1.) 1,2-dimethoxyethane , Ethanol heat for 14.5 h; 2.) 15 min,0 deg C 2: 1.) O3; 2.) Zn,50percentHOAc / 1.) CH2Cl2,- 78 deg C; 2.) reflux 3: 79 percent / Jones reagent / acetone 4: 95 percent / K2CO3 / acetone / 2 h / Heating 5: 97 percent / Br2 / acetic acid; acetic acid / 6.5 h 6: 91 percent / CaCO3 / N,N-dimethyl-acetamide / 0.75 h / Heating 7: 95 percent / KOH / H2O; ethanol / 15.5 h / Ambient temperature 8: 1.) Diisobutylaluminum hydride; 2.) 20percentH2SO4 / 1.) CH2Cl2, 0 deg C,benzene,15 min.; 45 min.at room temp.,2.) 30 min., 0 deg C 9: LDA 10: LDA 11: 100 percent / NaIO4 / OsO4 / H2O; 2-methyl-propan-2-ol / 30 h / Ambient temperature 12: 85 percent / Jones reagent / acetone 13: diethyl ether 14: 1.) NaNH2,bis(trimethylsilyl)amine 15: 1.) HCl; 2.) 2,4,5-collidine / 1.) CH2Cl2,-20 deg C; 2.) 180-185 deg C, 25 min. 16: 75 percent / 1,5-diazabicyclo<5.4.0>undec-5-ene / various solvent(s) / 2.5 h / 180 - 185 °C 17: LiAlH4 / diethyl ether / 2 h / 0 °C 18: 1.) Li, NH3; 2.) Jones reagent / 1.) Ether, -33 deg C; 2.) 0 deg C, 30 min View Scheme