| Abstract: | 2-Aminopyridine, sesamol and 4-hydroxy-3,5-dimethoxybenzaldehyde condense to form a Mannicb base 3b which reacts with tetronic acid to yield lactone 4c . Cyclization of 4c yields the benzopyran lactone 1b ; this inhibits growth of tumors in NCI in vitro tests. Alkaline hydrolysis of acetylated and methylated intermediate lactones, e.g. 4e , in the presence of acetone leads to the formation of novel lactones, e.g., of type 6 , which incorporate the acetone nucleus. Compound 6 is of interest since it inhibits tumor growth in vitro and has been selected by NCI for ongoing in vivo testing with human cancers. Heating 3b with mixtures of propionaldehyde and secondary amines such as morpholine leads to 3-methylbenzopyrans containing the amine nucleus, e.g. 7b. Unlike 3,4,5-trimethoxyphenyl compounds, e.g. 7a , phenolic analogs of type 7b do not inhibit growth of tumors in vitro. |
