jo991570o_si_001.pdf (769.26 kB)
Inter- and Intramolecular Pathways for the Formation of Tetrahydrofurans from β-(Phosphatoxy)alkyl Radicals. Evidence for a Dissociative Mechanism
journal contribution
posted on 1999-12-29, 00:00 authored by David Crich, Xianhai Huang, Martin Newcombβ-(Phosphatoxy)alkyl radicals generated by photolysis of Barton PTOC esters in the presence of
allyl alcohol and tert-butyl mercaptan undergo nucleophilic substitution followed by 5-exo-trig radical
ring closure leading to tetrahydrofurans in good yield and with high trans selectivity. β-(Phosphatoxy)alkyl radicals obtained by intramolecular hydrogen 1,5-abstraction with an alkoxyl radical
undergo nucleophilic displacement providing tetrahydrofurans. The ensemble of results, including
the effects of leaving groups and substituents, strongly support a dissociative mechanism for these
radical nucleophilic displacement reactions.