Compelling evidence for a stepwise mechanism of the alkaline cyclisation of uridine 3'-phosphate esters.
A Bronsted graph with a convex break at pK(a)(Lg)= 12.58 provides compelling evidence for an intermediate in the alkaline cyclisation of uridine 3'-phosphate esters. The transient pentacoordinated oxyphosphorane dianion intermediate collapses to reactant and cyclic uridine 2',3'-monophosphate faster than it can pseudo-rotate and isomerise to the 2'-isomer.
Department of Chemistry, University of Turku, FIN-20014, Turku, Finland. harlon@utu.fi
Harri
H
Lonnberg
Roger
R
Stromberg
Andrew
A
Williams
D003500:Cyclization; D004952:Esters / Q000737:chemistry*; D007536:Isomerism; D008956:Models, Chemical; D010753:Phosphoranes / Q000737:chemistry; D014542:Uridine Monophosphate / Q000031:analogs & derivatives* / Q000737:chemistry
D004952:Esters; D010753:Phosphoranes; C031034:3'-uridylic acid; D014542:Uridine Monophosphate