1: methyllithium With iron(III) chloride in diethyl ether cooling; 2: trifluoromethanesulfonic acid 5-oxo-2,5-dihydrofuran-3-yl ester in tetrahydrofuran T=-30°C;

1-methyl-pyrrolidin-2-one; iron (III) acetylacetonate in tetrahydrofuran T=-30°C;

1-methyl-pyrrolidin-2-one; iron (III) acetylacetonate in tetrahydrofuran T=-30°C;

Stage #1: <a href="#" onclick="return RXDsubstances(event, this, '108442', constants.ctx, '0')">2,4(3H,5H)-furandione</a> <b>With</b>&nbsp; <a href="#" onclick="return RXDsubstances(event, this, '110562', constants.ctx, '0')">N,N'-dimethyl-N,N'-propyleneurea</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;2&nbsp;h;&nbsp;<br />Stage #2: <a href="#" onclick="return RXDsubstances(event, this, '2214142', constants.ctx, '0')">N-phenyl-1,1,1-trifluoromethanesulfonamide</a> &nbsp;<b>in</b>&nbsp; <a href="#" onclick="return RXDsubstances(event, this, '102391', constants.ctx, '0')">tetrahydrofuran</a> <br />T=0&deg;C;&nbsp;9&nbsp;h;&nbsp;<br /> &nbsp;