rac-tert-butyl 7,8-dihydroxy-2,3-diphenyl-7,8-dihydropyrido[2,3-b]pyrazine-5(6H)-carboxylate

rac-5-(tert-butoxycarbonyl)-2,3-diphenyl-5,6,7,8-tetrahydropyrido[2,3-b]pyrazine-7,8-diyl diacetate

rac-7-(8-ethyl-2,3-diphenyl-7,8-dihydropyrido[2,3-b]pyrazin-5(6H)-yl)heptanoic acid

rac-8-ethyl-2,3-diphenyl-5,6,7,8-tetrahydropyrido[2,3-b]pyrazine

rac-ethyl 7-(8-ethyl-2,3-diphenyl-7,8-dihydropyrido[2,3-b]pyrazin-5(6H)-yl)heptanoate