1.1: 92 percent / imidazole / dimethylformamide / 2 h / 40 °C 2.1: t-butyllithium / diethyl ether; pentane / 0.5 h / -78 °C 2.2: 51 percent / TMEDA / diethyl ether; pentane / 0.08 h / -78 °C 3.1: 90 percent / Dess-Martin periodinane; sodium bicarbonate / CH2Cl2 / 1 h / 20 °C 4.1: TBAF / tetrahydrofuran / 0.5 h / 0 °C 5.1: 25 mg / HCl / 2-methyl-butan-2-ol / 2 h / 20 °C 6.1: 83 percent / imidazole / dimethylformamide / 2 h / 20 °C 7.1: 87 percent / DDQ / CH2Cl2; H2O / 0.5 h / 20 °C 8.1: 81 percent / pyridine / CH2Cl2 / 0.17 h / -78 °C 9.1: 9-BBN / tetrahydrofuran / 2 h / 40 °C 9.2: 37 percent / thallium carbonate; triphenylarsine / [1,1'-bis(diphenylphosphino)ferrocene]dichloropalladium(II) / tetrahydrofuran; dimethylformamide; H2O / 12 h / 20 °C 10.1: 78 percent / TBAF / tetrahydrofuran / 0.5 h / 0 °C View Scheme

<b>Multi-step reaction with 14 steps<br /> </b>1.1: diisopropyl amine; n-butyllithium; triethylamine / chlorotrimethylsilane / tetrahydrofuran; petroleum ether / -78 - 0 &deg;C<br />1.2: bromine / tetrahydrofuran; petroleum ether / 2 h / -78 &deg;C<br />2.1: 5.0 g / lithium carbonate; lithium bromide / dimethylformamide / 4 h / 100 - 105 &deg;C<br />3.1: diisopropyl amine; n-butyllithium / diethyl ether; petroleum ether / 0.58 h / -78 &deg;C<br />3.2: diethyl ether; petroleum ether / 1 h / -78 &deg;C<br />4.1: 378 mg / triethylamine; methanesulfonyl chloride / CH₂Cl₂ / 4 h / 20 &deg;C<br />5.1: lithium chloride / tetrahydrofuran / 2 h / 20 &deg;C<br />5.2: n-butyllithium / tetrahydrofuran; petroleum ether / 0.08 h / -78 &deg;C<br />5.3: 70 percent / tetrahydrofuran; petroleum ether / 0.5 h / -78 &deg;C<br />6.1: 91 percent / PCC / CH₂Cl₂ / 48 h / 20 &deg;C<br />7.1: cerium trichloride; sodium borohydride / methanol / 0.5 h / 0 &deg;C<br />8.1: 173 mg / mCPBA / CH₂Cl₂ / 1 h / 0 &deg;C<br />9.1: 86 percent / Dess-Martin periodonane; sodium bicarbonate / CH₂Cl₂ / 1 h / 20 &deg;C<br />10.1: magnesium bromide diethyl etherate / CH₂Cl₂ / 12 h / -78 &deg;C<br />11.1: 1.0 g / pyridine; trifluoroacetic anhydride; triethylamine / CH₂Cl₂ / 3.5 h / 0 - 20 &deg;C<br />12.1: magnesium bromide diethyl etherate; butanethiol / diethyl ether / 15 h / 20 &deg;C<br />12.2: 77 percent / camphorsulfonic acid / CH₂Cl₂ / 18 h / 20 &deg;C<br />13.1: 94 percent / cerium trichloride; sodium borohydride / methanol / 0.5 h / 0 &deg;C<br />14.1: triphenylphosphine; diethyl azodicarboxylate; 4-nitrobenzoic acid / tetrahydrofuran / 12 h / 20 &deg;C<br />14.2: 86 percent / sodium methoxide / methanol / 1 h / 20 &deg;C<br /> <br /> &nbsp;

<b>Multi-step reaction with 15 steps<br /> </b>1.1: 75 percent / KOH / Heating<br />2.1: diisopropyl amine; n-butyllithium; triethylamine / chlorotrimethylsilane / tetrahydrofuran; petroleum ether / -78 - 0 &deg;C<br />2.2: bromine / tetrahydrofuran; petroleum ether / 2 h / -78 &deg;C<br />3.1: 5.0 g / lithium carbonate; lithium bromide / dimethylformamide / 4 h / 100 - 105 &deg;C<br />4.1: diisopropyl amine; n-butyllithium / diethyl ether; petroleum ether / 0.58 h / -78 &deg;C<br />4.2: diethyl ether; petroleum ether / 1 h / -78 &deg;C<br />5.1: 378 mg / triethylamine; methanesulfonyl chloride / CH₂Cl₂ / 4 h / 20 &deg;C<br />6.1: lithium chloride / tetrahydrofuran / 2 h / 20 &deg;C<br />6.2: n-butyllithium / tetrahydrofuran; petroleum ether / 0.08 h / -78 &deg;C<br />6.3: 70 percent / tetrahydrofuran; petroleum ether / 0.5 h / -78 &deg;C<br />7.1: 91 percent / PCC / CH₂Cl₂ / 48 h / 20 &deg;C<br />8.1: cerium trichloride; sodium borohydride / methanol / 0.5 h / 0 &deg;C<br />9.1: 173 mg / mCPBA / CH₂Cl₂ / 1 h / 0 &deg;C<br />10.1: 86 percent / Dess-Martin periodonane; sodium bicarbonate / CH₂Cl₂ / 1 h / 20 &deg;C<br />11.1: magnesium bromide diethyl etherate / CH₂Cl₂ / 12 h / -78 &deg;C<br />12.1: 1.0 g / pyridine; trifluoroacetic anhydride; triethylamine / CH₂Cl₂ / 3.5 h / 0 - 20 &deg;C<br />13.1: magnesium bromide diethyl etherate; butanethiol / diethyl ether / 15 h / 20 &deg;C<br />13.2: 77 percent / camphorsulfonic acid / CH₂Cl₂ / 18 h / 20 &deg;C<br />14.1: 94 percent / cerium trichloride; sodium borohydride / methanol / 0.5 h / 0 &deg;C<br />15.1: triphenylphosphine; diethyl azodicarboxylate; 4-nitrobenzoic acid / tetrahydrofuran / 12 h / 20 &deg;C<br />15.2: 86 percent / sodium methoxide / methanol / 1 h / 20 &deg;C<br /> <br /> &nbsp;

<b>Multi-step reaction with 13 steps<br /> </b>1.1: 5.0 g / lithium carbonate; lithium bromide / dimethylformamide / 4 h / 100 - 105 &deg;C<br />2.1: diisopropyl amine; n-butyllithium / diethyl ether; petroleum ether / 0.58 h / -78 &deg;C<br />2.2: diethyl ether; petroleum ether / 1 h / -78 &deg;C<br />3.1: 378 mg / triethylamine; methanesulfonyl chloride / CH₂Cl₂ / 4 h / 20 &deg;C<br />4.1: lithium chloride / tetrahydrofuran / 2 h / 20 &deg;C<br />4.2: n-butyllithium / tetrahydrofuran; petroleum ether / 0.08 h / -78 &deg;C<br />4.3: 70 percent / tetrahydrofuran; petroleum ether / 0.5 h / -78 &deg;C<br />5.1: 91 percent / PCC / CH₂Cl₂ / 48 h / 20 &deg;C<br />6.1: cerium trichloride; sodium borohydride / methanol / 0.5 h / 0 &deg;C<br />7.1: 173 mg / mCPBA / CH₂Cl₂ / 1 h / 0 &deg;C<br />8.1: 86 percent / Dess-Martin periodonane; sodium bicarbonate / CH₂Cl₂ / 1 h / 20 &deg;C<br />9.1: magnesium bromide diethyl etherate / CH₂Cl₂ / 12 h / -78 &deg;C<br />10.1: 1.0 g / pyridine; trifluoroacetic anhydride; triethylamine / CH₂Cl₂ / 3.5 h / 0 - 20 &deg;C<br />11.1: magnesium bromide diethyl etherate; butanethiol / diethyl ether / 15 h / 20 &deg;C<br />11.2: 77 percent / camphorsulfonic acid / CH₂Cl₂ / 18 h / 20 &deg;C<br />12.1: 94 percent / cerium trichloride; sodium borohydride / methanol / 0.5 h / 0 &deg;C<br />13.1: triphenylphosphine; diethyl azodicarboxylate; 4-nitrobenzoic acid / tetrahydrofuran / 12 h / 20 &deg;C<br />13.2: 86 percent / sodium methoxide / methanol / 1 h / 20 &deg;C<br /> <br /> &nbsp;

<b>Multi-step reaction with 3 steps<br /> </b>1.1: magnesium bromide diethyl etherate; butanethiol / diethyl ether / 15 h / 20 &deg;C<br />1.2: 77 percent / camphorsulfonic acid / CH₂Cl₂ / 18 h / 20 &deg;C<br />2.1: 94 percent / cerium trichloride; sodium borohydride / methanol / 0.5 h / 0 &deg;C<br />3.1: triphenylphosphine; diethyl azodicarboxylate; 4-nitrobenzoic acid / tetrahydrofuran / 12 h / 20 &deg;C<br />3.2: 86 percent / sodium methoxide / methanol / 1 h / 20 &deg;C<br /> <br /> &nbsp;

<b>Multi-step reaction with 16 steps<br /> </b>1.1: 70 percent / LDA; LiCl<br />2.1: 75 percent / KOH / Heating<br />3.1: diisopropyl amine; n-butyllithium; triethylamine / chlorotrimethylsilane / tetrahydrofuran; petroleum ether / -78 - 0 &deg;C<br />3.2: bromine / tetrahydrofuran; petroleum ether / 2 h / -78 &deg;C<br />4.1: 5.0 g / lithium carbonate; lithium bromide / dimethylformamide / 4 h / 100 - 105 &deg;C<br />5.1: diisopropyl amine; n-butyllithium / diethyl ether; petroleum ether / 0.58 h / -78 &deg;C<br />5.2: diethyl ether; petroleum ether / 1 h / -78 &deg;C<br />6.1: 378 mg / triethylamine; methanesulfonyl chloride / CH₂Cl₂ / 4 h / 20 &deg;C<br />7.1: lithium chloride / tetrahydrofuran / 2 h / 20 &deg;C<br />7.2: n-butyllithium / tetrahydrofuran; petroleum ether / 0.08 h / -78 &deg;C<br />7.3: 70 percent / tetrahydrofuran; petroleum ether / 0.5 h / -78 &deg;C<br />8.1: 91 percent / PCC / CH₂Cl₂ / 48 h / 20 &deg;C<br />9.1: cerium trichloride; sodium borohydride / methanol / 0.5 h / 0 &deg;C<br />10.1: 173 mg / mCPBA / CH₂Cl₂ / 1 h / 0 &deg;C<br />11.1: 86 percent / Dess-Martin periodonane; sodium bicarbonate / CH₂Cl₂ / 1 h / 20 &deg;C<br />12.1: magnesium bromide diethyl etherate / CH₂Cl₂ / 12 h / -78 &deg;C<br />13.1: 1.0 g / pyridine; trifluoroacetic anhydride; triethylamine / CH₂Cl₂ / 3.5 h / 0 - 20 &deg;C<br />14.1: magnesium bromide diethyl etherate; butanethiol / diethyl ether / 15 h / 20 &deg;C<br />14.2: 77 percent / camphorsulfonic acid / CH₂Cl₂ / 18 h / 20 &deg;C<br />15.1: 94 percent / cerium trichloride; sodium borohydride / methanol / 0.5 h / 0 &deg;C<br />16.1: triphenylphosphine; diethyl azodicarboxylate; 4-nitrobenzoic acid / tetrahydrofuran / 12 h / 20 &deg;C<br />16.2: 86 percent / sodium methoxide / methanol / 1 h / 20 &deg;C<br /> <br /> &nbsp;