- Syntheses and structure-activity relationships of 5,6,7, 8-tetrahydro-5,5,8,8-tetramethyl-2-quinoxaline derivatives with retinoic acid receptor alpha agonistic activity. Kikuchi, K., Hibi, S., Yoshimura, H., Tokuhara, N., Tai, K., Hida, T., Yamauchi, T., Nagai, M. J. Med. Chem. (2000)