1.1: potassium carbonate / butan-1-ol / 5 h / 110 °C 2.1: iso-propylmagnesium bromide; bis(cyclopentadienyl)titanium dichloride / tetrahydrofuran / 24 h / |Reflux 2.2: 0 °C 3.1: trimethylsilyl trifluoromethanesulfonate / acetonitrile / 18 h / |Reflux 4.1: sodium methylate; methanol / 6 h / 20 °C View Scheme

1: trimethylsilyl trifluoromethanesulfonate / acetonitrile / 18 h / |Reflux 2: sodium methylate; methanol / 6 h / 20 °C View Scheme