Retinoids and related compounds; 18: A convenient synthesis of retinoic acid analogs having an anthraquinone ring

Article abstract of DOI:10.1055/s-1995-4063

Synthesis of retinoic acid analogs involving an anthraquinone ring is described. The reaction of p-toluenesulfonylmethylanthraquinones 8 with ethyl 8-chloro-3,7-dimethyl-2,4,6-octatrienoate (6) and subsequent desulfonylation afforded the esters 10 and 11 as a mixture of terminal double bond isomers. After separation of these isomers, basic hydrolysis using 10% potassium hydroxide gave the corresponding acids 12 and 13, respectively, without isomerization of the terminal double bond in excellent yields.