1: 83 percent / Zn; NH4Cl / methanol 2: 76 percent / Hunig's base / CH2Cl2 3: 88 percent / HF*pyridine / acetonitrile / 10 h / 20 °C 4: 71 percent / BF3*Et2O / CH2Cl2 / 2 h 5: piperidine / dimethylformamide / 0.08 h 6: 7.1 mg / Et3N; DMAP / CH2Cl2 / 1 h / 20 °C 7: 72 percent / Grubbs second-generation ruthenium carbene catalyst / CH2Cl2 / 24 h / Heating 8: CF3CO2H / CH2Cl2; H2O / 12 h 9: 10.3 mg / NaOMe / methanol / 12 h View Scheme

1: 83 percent / NH4Cl; Zn / methanol / 2 h / 20 °C 2: 76 percent / diisopropylethylamine / toluene / 2 h / 20 °C 3: 82 percent / RuCl2[(1,3-dimesitylimidazolidine-2-yl)(PCy3)(benzylidene)] / CH2Cl2 / 36 h / Heating 4: piperidine / dimethylformamide / 0.08 h 5: 12 mg / DMAP; Et3N / CH2Cl2 / 3 h / 20 °C 6: 72 percent / TFA / CH2Cl2; H2O / 2 h 7: 40 percent / TBAF / tetrahydrofuran / 1 h / 20 °C View Scheme

<b>Multi-step reaction with 3 steps<br /> </b>1.1: imidazole / tetrahydrofuran / 0.5 h / 20 &deg;C<br />2.1: 1.76 g / La(OTf)3 / toluene / 1 h / 20 &deg;C<br />3.1: NaN₃; Bu₄NCl / dimethylformamide / 24 h / 90 &deg;C<br />3.2: 300 mg / Et₃N; DMAP / CH₂Cl₂ <br /> <br /> &nbsp;

Stage #1: <a href="#" onclick="return RXDsubstances(event, this, '10209406', constants.ctx, '0')">Methanesulfonic acid (1R,2R)-1-(tert-butyl-diphenyl-silanyloxymethyl)-2-(4-methoxy-benzyloxy)-but-3-enyl ester</a> <b>With</b>&nbsp; <a href="#" onclick="return RXDsubstances(event, this, '1209320', constants.ctx, '0')">sodium azide</a>;&nbsp;<a href="#" onclick="return RXDsubstances(event, this, '3571227', constants.ctx, '0')">tetrabutyl-ammonium chloride</a>&nbsp;<b>in</b>&nbsp; <a href="#" onclick="return RXDsubstances(event, this, '605365', constants.ctx, '0')">N,N-dimethyl-formamide</a> <br />T=90&deg;C;&nbsp;24&nbsp;h;&nbsp;<br />Stage #2: <a href="#" onclick="return RXDsubstances(event, this, '644023', constants.ctx, '0')">tert-butylchlorodiphenylsilane</a> <b>With</b>&nbsp; <a href="#" onclick="return RXDsubstances(event, this, '110354', constants.ctx, '0')">4-(N,N-dimethlyamino)pyridine</a>;&nbsp;<a href="#" onclick="return RXDsubstances(event, this, '605283', constants.ctx, '0')">triethylamine</a>&nbsp;<b>in</b>&nbsp; <a href="#" onclick="return RXDsubstances(event, this, '1730800', constants.ctx, '0')">dichloromethane</a> <br /> <br /> &nbsp;

<b>Multi-step reaction with 3 steps<br /> </b>1.1: imidazole / tetrahydrofuran / 0.5 h / 20 &deg;C<br />2.1: 1.76 g / La(OTf)3 / toluene / 1 h / 20 &deg;C<br />3.1: NaN₃; Bu₄NCl / dimethylformamide / 24 h / 90 &deg;C<br />3.2: 300 mg / Et₃N; DMAP / CH₂Cl₂ <br /> <br /> &nbsp;