1: 1.) borane*THF, cyclohexane; 2.) aq. KOH, H2O2 / 1.) THF, 2 h; 2.) MeOH, RT, 1.5 h 2: 82 percent / diethyl ether / Ambient temperature 3: 56 percent / lithium di-isopropylamide, HMPA / tetrahydrofuran 4: 88 percent / KOH / methanol / 16 h / Ambient temperature 5: 20 percent / Et3N, diphenylphosphoryl azide / toluene / 7 h / Heating 6: Heating 7: 1.) O3; 2.) NaBH4 / 1.) CH2Cl2, -15 deg C, 8 min; 2.) EtOH, 0 deg C, 1.5 h View Scheme

1: 1.) borane*THF, cyclohexane; 2.) aq. KOH, H2O2 / 1.) THF, 2 h; 2.) MeOH, RT, 1.5 h 2: 82 percent / diethyl ether / Ambient temperature 3: 56 percent / lithium di-isopropylamide, HMPA / tetrahydrofuran 4: 88 percent / KOH / methanol / 16 h / Ambient temperature 5: 20 percent / Et3N, diphenylphosphoryl azide / toluene / 7 h / Heating 6: Heating 7: 1.) O3; 2.) NaBH4 / 1.) CH2Cl2, -15 deg C, 8 min; 2.) EtOH, 0 deg C, 1.5 h View Scheme

<b>Multi-step reaction with 3 steps<br /> </b>1: 91 percent / dimethylformamide / 4 h<br />2: 68.2 g / di-isobutylaluminium hydride / hexane / 0.5 h / -60 &deg;C<br />3: 1.) butyl-lithium / 1.) THF, hexane, 30 min, -60 deg C; 2.) THF, RT, 1 h<br /> <br /> &nbsp;

<b>Multi-step reaction with 2 steps<br /> </b>1: 68.2 g / di-isobutylaluminium hydride / hexane / 0.5 h / -60 &deg;C<br />2: 1.) butyl-lithium / 1.) THF, hexane, 30 min, -60 deg C; 2.) THF, RT, 1 h<br /> <br /> &nbsp;

<b>Multi-step reaction with 4 steps<br /> </b>1: SOCl₂ / 16 h / Heating<br />2: 91 percent / dimethylformamide / 4 h<br />3: 68.2 g / di-isobutylaluminium hydride / hexane / 0.5 h / -60 &deg;C<br />4: 1.) butyl-lithium / 1.) THF, hexane, 30 min, -60 deg C; 2.) THF, RT, 1 h<br /> <br /> &nbsp;

<b>Multi-step reaction with 3 steps<br /> </b>1: 1) hydroxybenzotriazole monohydrate, dicyclohexylcarbodiimide, 2) triethylamine / 1) CH₂Cl₂, 0 deg C, 2) overnight, RT<br />2: 78 percent / LiAlH₄ / diethyl ether / 0.33 h / -5 &deg;C<br />3: n-butyllithium / hexane<br /> <br /> &nbsp;