Synthesis and Properties of Conformationally Rigid Cyclouridylic Acids Having Covalent Bonding Linkers Between the Uracil 5-Position and the 5′-Phosphate Group

Abstract

Conformationally rigid cyclouridylic acid derivatives 2 and 3 having ethylene and propylene bridges, respectively, between the uracil 5-position and the 5′-phosphate group were synthesized. These intramolecularly cyclized compounds have predominantly the ribose pucker of C3′-endo and the g+ orientation around the C4′-C5′ bond.

Notes

The fractional population of C3′-endo was caluculated by the equation of %(C3′-endo) = (J _3′,4′/ J _1′,2′ + J3′,4′) x100: Altona, C.; Sundaralingham, M. J. Am. Chem. Soc. 1973, 95, 2333. In the pesent study the population of the g+ conformation around the C4′-C5′ bond was calculated using the equation %g+ = (13.3-(J _4′,5′+J _4′,5′))/9.7: Altona, C. Reel. Trav. Chim. Pays-Bas 1982, 101 413