1: 1) 2,6-lutidine, trimethylsilyl trifluoromethanesulfonate, 2) Bu4NF, AcOH / 1) CH2Cl2, -60 deg C to 10 deg C, 2 h, 2) THF, 30 min 2: 86 percent / N,N-diethyl-N<<(methoxycarbonyl)amino>sulfonyl>ethanaminium hydroxide / benzene / 0.25 h / 80 °C 3: 85 percent / Bu4NF, AcOH / tetrahydrofuran; H2O / 29 h View Scheme

<b>Multi-step reaction with 18 steps<br /> </b>1: 92 percent / 48 h / 130 &deg;C<br />2: 1) disiamylborane, BH₃*SMe₂, 2) 30percent H₂O₂ / 1) THF, r.t., 30 min, 2) MeOH<br />3: 84 percent / (COCl)2, DMSO / CH₂Cl₂ / 0.05 h / -30 &deg;C<br />4: Me₂AlCl, MeOH / CH₂Cl₂; hexane / 0.5 h / -40 deg C to r.t.<br />5: 99.4 percent / tetrahydrofuran / 2 h / Ambient temperature<br />6: 64 percent / NH₃ liq., Li / tetrahydrofuran / 1 h<br />7: 1) KOtBu / 1) THF, r.t., 1 h, 2) THF, r.t., 15 min<br />8: Bu₄NF / tetrahydrofuran / 3 h / Ambient temperature<br />9: pyridine, 4-(N,N-dimethylamino)pyridine / Ambient temperature<br />10: 87 percent / p-TsOH, H₂O / acetone / 2 h / 56 &deg;C<br />12: 66 percent / Et₃N / 20 h / Ambient temperature<br />13: 1) s-Bu₃BHLi, 2) H₂O₂ / 1) THF, -78 deg C, 30 min, 2) THF, H₂O, to r.t.<br />14: KOH / methanol / 2 h / 60 &deg;C<br />15: 99 percent / imidazole / dimethylformamide / 3 h / 80 &deg;C<br />16: VO(acac)2, tert-butylhydroperoxide / CH₂Cl₂ / 3 h / 0 &deg;C<br />17: 89 percent / pyridine, 4-(N,N-dimethylamino)pyridine / 48 h / Ambient temperature<br />18: 67 percent / CrO₃, AcOH / CH₂Cl₂; H₂O / 2 h<br /> <br /> &nbsp;

<b>Multi-step reaction with 12 steps<br /> </b>1: 1) KOtBu / 1) THF, r.t., 1 h, 2) THF, r.t., 15 min<br />2: Bu₄NF / tetrahydrofuran / 3 h / Ambient temperature<br />3: pyridine, 4-(N,N-dimethylamino)pyridine / Ambient temperature<br />4: 87 percent / p-TsOH, H₂O / acetone / 2 h / 56 &deg;C<br />6: 66 percent / Et₃N / 20 h / Ambient temperature<br />7: 1) s-Bu₃BHLi, 2) H₂O₂ / 1) THF, -78 deg C, 30 min, 2) THF, H₂O, to r.t.<br />8: KOH / methanol / 2 h / 60 &deg;C<br />9: 99 percent / imidazole / dimethylformamide / 3 h / 80 &deg;C<br />10: VO(acac)2, tert-butylhydroperoxide / CH₂Cl₂ / 3 h / 0 &deg;C<br />11: 89 percent / pyridine, 4-(N,N-dimethylamino)pyridine / 48 h / Ambient temperature<br />12: 67 percent / CrO₃, AcOH / CH₂Cl₂; H₂O / 2 h<br /> <br /> &nbsp;

<b>Multi-step reaction with 4 steps<br /> </b>1: 99 percent / imidazole / dimethylformamide / 3 h / 80 &deg;C<br />2: VO(acac)2, tert-butylhydroperoxide / CH₂Cl₂ / 3 h / 0 &deg;C<br />3: 89 percent / pyridine, 4-(N,N-dimethylamino)pyridine / 48 h / Ambient temperature<br />4: 67 percent / CrO₃, AcOH / CH₂Cl₂; H₂O / 2 h<br /> <br /> &nbsp;

<b>Multi-step reaction with 17 steps<br /> </b>1: 1) disiamylborane, BH₃*SMe₂, 2) 30percent H₂O₂ / 1) THF, r.t., 30 min, 2) MeOH<br />2: 84 percent / (COCl)2, DMSO / CH₂Cl₂ / 0.05 h / -30 &deg;C<br />3: Me₂AlCl, MeOH / CH₂Cl₂; hexane / 0.5 h / -40 deg C to r.t.<br />4: 99.4 percent / tetrahydrofuran / 2 h / Ambient temperature<br />5: 64 percent / NH₃ liq., Li / tetrahydrofuran / 1 h<br />6: 1) KOtBu / 1) THF, r.t., 1 h, 2) THF, r.t., 15 min<br />7: Bu₄NF / tetrahydrofuran / 3 h / Ambient temperature<br />8: pyridine, 4-(N,N-dimethylamino)pyridine / Ambient temperature<br />9: 87 percent / p-TsOH, H₂O / acetone / 2 h / 56 &deg;C<br />11: 66 percent / Et₃N / 20 h / Ambient temperature<br />12: 1) s-Bu₃BHLi, 2) H₂O₂ / 1) THF, -78 deg C, 30 min, 2) THF, H₂O, to r.t.<br />13: KOH / methanol / 2 h / 60 &deg;C<br />14: 99 percent / imidazole / dimethylformamide / 3 h / 80 &deg;C<br />15: VO(acac)2, tert-butylhydroperoxide / CH₂Cl₂ / 3 h / 0 &deg;C<br />16: 89 percent / pyridine, 4-(N,N-dimethylamino)pyridine / 48 h / Ambient temperature<br />17: 67 percent / CrO₃, AcOH / CH₂Cl₂; H₂O / 2 h<br /> <br /> &nbsp;

<b>Multi-step reaction with 15 steps<br /> </b>1: Me₂AlCl, MeOH / CH₂Cl₂; hexane / 0.5 h / -40 deg C to r.t.<br />2: 99.4 percent / tetrahydrofuran / 2 h / Ambient temperature<br />3: 64 percent / NH₃ liq., Li / tetrahydrofuran / 1 h<br />4: 1) KOtBu / 1) THF, r.t., 1 h, 2) THF, r.t., 15 min<br />5: Bu₄NF / tetrahydrofuran / 3 h / Ambient temperature<br />6: pyridine, 4-(N,N-dimethylamino)pyridine / Ambient temperature<br />7: 87 percent / p-TsOH, H₂O / acetone / 2 h / 56 &deg;C<br />9: 66 percent / Et₃N / 20 h / Ambient temperature<br />10: 1) s-Bu₃BHLi, 2) H₂O₂ / 1) THF, -78 deg C, 30 min, 2) THF, H₂O, to r.t.<br />11: KOH / methanol / 2 h / 60 &deg;C<br />12: 99 percent / imidazole / dimethylformamide / 3 h / 80 &deg;C<br />13: VO(acac)2, tert-butylhydroperoxide / CH₂Cl₂ / 3 h / 0 &deg;C<br />14: 89 percent / pyridine, 4-(N,N-dimethylamino)pyridine / 48 h / Ambient temperature<br />15: 67 percent / CrO₃, AcOH / CH₂Cl₂; H₂O / 2 h<br /> <br /> &nbsp;