Download full text in PDF Opens in a new window. Article suggestions will be shown in a dialog on return to ScienceDirect. ... Please enable JavaScript to use all the features on this page. ... Reductive cyclisations using Bu 3 SnH include an “oxidation” step if the removal of an acidic proton from the intermediate cyclised radical, by Bu 3 SnH acting as a base, is favourable. A “pseudo” S RN 1 mechanism is proposed. ... J. Chem. Soc. (1986), pp. 115–116 Chem. ...