1: NaBH4 / methanol / 0 °C 2: H2SO4 / diethyl ether 3: KO-t-Bu / tetrahydrofuran 4: DIBAH / toluene / -78 °C 5: NaH / tetrahydrofuran / 0 °C 6: 1.) O3; 2.) Me2S / 1.) CH2Cl2, -78 deg C; 2.) reflux 7: NaOH / methanol / Heating 8: DIBAH / diethyl ether / -100 °C 9: Et2Zn / toluene / 60 °C 10: PCC / CH2Cl2 11: tetrahydrofuran View Scheme

1: Et2Zn / toluene / 60 °C 2: PCC / CH2Cl2 3: tetrahydrofuran View Scheme

1: DIBAH / diethyl ether / -100 °C 2: Et2Zn / toluene / 60 °C 3: PCC / CH2Cl2 4: tetrahydrofuran View Scheme

1: PCC / CH2Cl2 2: tetrahydrofuran View Scheme

1: NaH / tetrahydrofuran / 0 °C 2: 1.) O3; 2.) Me2S / 1.) CH2Cl2, -78 deg C; 2.) reflux 3: NaOH / methanol / Heating 4: DIBAH / diethyl ether / -100 °C 5: Et2Zn / toluene / 60 °C 6: PCC / CH2Cl2 7: tetrahydrofuran View Scheme

1: 1.) O3; 2.) Me2S / 1.) CH2Cl2, -78 deg C; 2.) reflux 2: NaOH / methanol / Heating 3: DIBAH / diethyl ether / -100 °C 4: Et2Zn / toluene / 60 °C 5: PCC / CH2Cl2 6: tetrahydrofuran View Scheme

1: DIBAH / toluene / -78 °C 2: NaH / tetrahydrofuran / 0 °C 3: 1.) O3; 2.) Me2S / 1.) CH2Cl2, -78 deg C; 2.) reflux 4: NaOH / methanol / Heating 5: DIBAH / diethyl ether / -100 °C 6: Et2Zn / toluene / 60 °C 7: PCC / CH2Cl2 8: tetrahydrofuran View Scheme

1: NaOH / methanol / Heating 2: DIBAH / diethyl ether / -100 °C 3: Et2Zn / toluene / 60 °C 4: PCC / CH2Cl2 5: tetrahydrofuran View Scheme

1: 87 percent / tributylamine, thionyl chloride / 1 h 2: 1.) magnesium / 1.) THF, reflux, 1.5 h., 2.) benzene, THF, room temp., 2 h. 4: diisobutylaluminum hydride / diethyl ether / 0.5 h / -105 - -95 °C 5: diethyl zinc, O2 / toluene / 0.17 h 6: Celite, pyridinium chlorochromate / CH2Cl2 / 1.5 h / Ambient temperature 7: benzene / 2.25 h / Ambient temperature View Scheme

1: 1.) lithium aluminum hydride, 2.) 15percent NaOH / 1.) Et2O, from 0 deg C to room temp., 2 h., 2.) Et2O, water, 30 min. 2: 87 percent / tributylamine, thionyl chloride / 1 h 3: 1.) magnesium / 1.) THF, reflux, 1.5 h., 2.) benzene, THF, room temp., 2 h. 5: diisobutylaluminum hydride / diethyl ether / 0.5 h / -105 - -95 °C 6: diethyl zinc, O2 / toluene / 0.17 h 7: Celite, pyridinium chlorochromate / CH2Cl2 / 1.5 h / Ambient temperature 8: benzene / 2.25 h / Ambient temperature View Scheme