Synthesis of methyl derivatives of 8‐desmethylxanthyletine and 8‐desmethylseseline, potential antiproliferative agents

Abstract
A number of new methyl derivatives of pyranocoumarins, related to 8‐desmethylxanthyletine and to 8‐desmethylseseline, were synthesized. The syntheses were performed by cyclization in boiling N,N‐diethyl aniline of the propargyl or methylpropargyl ethers of the appropriate methyl derivatives of 7‐hydroxycou‐marin. Methyl groups have been introduced into positions which look most promising for enhancement of the photoreactivity of the compounds towards DNA.