1.1: 82 percent / LiBH4 / methanol; tetrahydrofuran / 2 h / 0 °C 2.1: 89 percent / pyridine; DMAP / 5 h / 20 °C 3.1: 100 percent / Grubbs first generation catalyst / toluene / 12 h / 80 °C 4.1: LAH / tetrahydrofuran / 12 h / 20 °C 5.1: toluene / 12 h / 80 °C 5.2: 0.21 g / K2CO3 / methanol / 12 h 6.1: 82 percent / O2 / benzene / 20 h / Irradiation View Scheme

Stage #1: <a href="#" onclick="return RXDsubstances(event, this, '4321286', constants.ctx, '0')">(4S)-3-(1-oxo-5-hexenyl)-4-benzyl-2-oxazolidinone</a> <b>With</b>&nbsp; <a href="#" onclick="return RXDsubstances(event, this, '1099903', constants.ctx, '0')">N,N,N',N',N'',N''-hexamethylphosphoric triamide</a>;&nbsp;<a href="#" onclick="return RXDsubstances(event, this, '906717', constants.ctx, '0')">lithium diisopropyl amide</a>&nbsp;<b>in</b>&nbsp; <a href="#" onclick="return RXDsubstances(event, this, '102391', constants.ctx, '0')">tetrahydrofuran</a> <br />T=-78&deg;C;&nbsp;0.5&nbsp;h;&nbsp;<br />Stage #2: <a href="#" onclick="return RXDsubstances(event, this, '605309', constants.ctx, '0')">propargyl bromide</a> &nbsp;<b>in</b>&nbsp; <a href="#" onclick="return RXDsubstances(event, this, '102391', constants.ctx, '0')">tetrahydrofuran</a> <br />T=-78&deg;C;&nbsp;24&nbsp;h;&nbsp;&nbsp;Further stages.;&nbsp;<br /> &nbsp;

<b>Multi-step reaction with 2 steps<br /> </b>1.1: pivaloyl chloride; NEt₃ / tetrahydrofuran / 1 h / -10 &deg;C<br />1.2: 96 percent / LiCl / tetrahydrofuran / 12 h / 20 &deg;C<br />2.1: LDA; HMPA / tetrahydrofuran / 0.5 h / -78 &deg;C<br />2.2: 89 percent / tetrahydrofuran / 24 h / -78 &deg;C<br /> <br /> &nbsp;