Five (2,2-dimethylchroman-6-yl)alkanoic acids were synthesized and tested for antigelling activities. It was envisioned that these agents might bind via hydrophobic bonding to nonpolar sites of the "donor-acceptor" regions of hemoglobin S. Several (2,2-dimethylchroman-6-yl)alkanoic acids containing 1-4 carbon atoms on the side-chain residue were designed to interact at the acceptor site, were synthesized, and were found to be moderately potent antigelling agents. The weak activity observed for two of the acids at low concentrations is rationalized in terms of weak binding affinities or multiple binding to active and nonactive sites. The effect of these compounds on shifting the allosteric equilibrium was small or negligible. The low toxicity of one of the (2,2-dimethylchroman-6-yl)alkanoic acids demonstrates the potential use of yet another class of compounds that can be modified in the development of antisickling agents.