Synthesis of novel 5-fluorouracil derivatives with 1,4-oxaheteroepane moieties

Using Neighboring-Group Participation for Acyclic Stereocontrol in Diastereoselective Substitution Reactions of Acetals

Neighboring-group participation of an ester enabled stereocontrol in substitution reactions of acyclic acetals. The ester group formed a trans-fused dioxolenium ion intermediate, which underwent a substitution reaction at the acetal carbon atom to afford the product with high diastereoselectivity. Neighboring-group participation was confirmed by isolating dioxolane products resulting from nucleophilic addition at C-2 of a 1,3-dioxolenium ion intermediate. Using a pivaloate ester as the participating group in combination with strong nucleophiles produced substitution products with diastereoselectivities of ≥90:10.

Antiproliferative activity, cell-cycle dysregulation, and cellular differentiation: salicyl- and catechol-derived acyclic 5-fluorouracil O,N-acetals against breast cancer cells

Herein we report the preparation and biological activity of three compounds with the general formula 1-[2-(5-substituted-2-hydroxybenzyloxy)-1-methoxyethyl]-5-fluorouracil. A catechol-derived compound such as 1-[3-(2-hydroxyphenoxy)-1-methoxypropyl]-5-fluorouracil and two salicyl-derived compounds such as (Z)-1-[4-(2-hydroxyphenyl)-1-methoxybut-3-enyl]-5-fluorouracil [(Z)-11] and its dihydrogenated derivative 1-[4-(2-hydroxyphenyl)-1-methoxybutyl]-5-fluorouracil were prepared to complete the set of six O,N-acetals. The most active compound against the MCF-7 breast cancer cell line was (Z)-11: IC(50)=9.40+/-0.64 microM. Differentiated breast cancer cells generate fat deposits in the cytoplasm. MCF-7 cells treated with (Z)-11 underwent an increase in lipid content relative to control cells after three days of treatment. Our results suggest that there may be significant potential advantages in the use of this new differentiating agent for the treatment of breast cancer.