title: The Stereochemical Course of the α-Hydroxyphosphonate-Phosphate Rearrangement.
abstract: The phosphonate-phosphate rearrangement is an isomerisation of α-hydroxyphosphonates bearing electron-withdrawing substituents at the α-carbon atom. We studied the stereochemical course of this rearrangement with respect to phosphorus. A set of four diastereomeric α-hydroxyphosphonates was prepared by a Pudovik reaction from two diastereomeric cyclic phosphites. The hydroxyphosphonates were separated and rearranged with Et3 N as base. In analogy to trichlorphon, which was the first reported compound undergoing this rearrangement. All four hydroxyphosphonates could be rearranged to 2,2-dichlorovinyl phosphates. Single-crystal X-ray structure analyses of the α-hydroxyphosphonates and the corresponding phosphates allowed us to show that the rearrangement proceeds with retention of configuration on the phosphorus atom.
authors.affiliation: Institute of Organic Chemistry, University of Vienna, Währingerstraße 38, 1090 Vienna (Austria).
authors.forename: Katharina
authors.initials: K
authors.lastname: Pallitsch
authors.affiliation: Institute of Inorganic Chemistry, University of Vienna, Währingerstraße 42, 1090 Vienna (Austria).
authors.forename: Alexander
authors.initials: A
authors.lastname: Roller
authors.affiliation: Institute of Organic Chemistry, University of Vienna, Währingerstraße 38, 1090 Vienna (Austria). friedrich.hammerschmidt@univie.ac.at.
authors.forename: Friedrich
authors.initials: F
authors.lastname: Hammerschmidt
keywords: phosphates; phosphites; phosphonates; reaction mechanisms; rearrangement