Facile Synthesis of Lipophilic δ-Amino Acid Conjugates from 4-Alkoxy-dithionaphthoic Acids

Abstract

Novel 4-alkoxy-dithionaphthoic acids were prepared and shown to be valuable synthons for δ-amino acid conjugates. These dithioacids are efficiently synthesized and purified, stable to storage, and easily derivatized to facilitate thioacylation chemistry. To this end, we have demonstrated dithionaphthoic acids (6) to successfully undergo coupling with both protected and unprotected amino acids, giving rise to stable thioamide conjugates (8 and 9).

GRAPHICAL ABSTRACT

Keywords:

• Bioconjugates
• dithioacid
• naphthalene
• thioacylation
• thioamide coupling

ACKNOWLEDGMENTS

This research was supported by an award from the Research Corporation for Science Advancement and Samford University. A. C. W. was supported by an Alabama Power Fellowship. The authors also thank Mike Jablonsky (University of Alabama, Birmingham) and Brian Gregory (Samford University) for use of their spectroscopic equipment facilities.