Synthesis of Tetrahydrofurans by a Tandem Hydrogen Atom Abstraction/Radical Nucleophilic Displacement Sequence
摘要:
The reaction of a series of 5-(N-phthalimidoxy)-1-phenyl-1-(diphenylphosphatoxy)pentanes with triphenyltin hydride and AIBN provides alkoxy radicals which undergo 1,5-hydrogen atom abstraction to give beta-(phosphatoxy)alkyl radicals. These radicals then take part in a radical nucleophilic displacement leading, after chain transfer, to tetrahydrofurans.
Synthesis of Tetrahydrofurans by a Tandem Hydrogen Atom Abstraction/Radical Nucleophilic Displacement Sequence
摘要:
The reaction of a series of 5-(N-phthalimidoxy)-1-phenyl-1-(diphenylphosphatoxy)pentanes with triphenyltin hydride and AIBN provides alkoxy radicals which undergo 1,5-hydrogen atom abstraction to give beta-(phosphatoxy)alkyl radicals. These radicals then take part in a radical nucleophilic displacement leading, after chain transfer, to tetrahydrofurans.
Inter- and Intramolecular Pathways for the Formation of Tetrahydrofurans from β-(Phosphatoxy)alkyl Radicals. Evidence for a Dissociative Mechanism
作者:David Crich、Xianhai Huang、Martin Newcomb
DOI:10.1021/jo991570o
日期:2000.1.1
mercaptan undergo nucleophilicsubstitution followed by 5-exo-trig radical ring closure leading to tetrahydrofurans in good yield and with high trans selectivity. beta-(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 leavinggroups and substituents