| Abstract: | A biomimetic synthesis of the anti-tumor active alkaloid acronycine (7; R=R'=Me) has been obtained by cyclisationof 6-(2-methylaminobenzoyl)-5,7-dimethoxy-2.2-dimethylchromene (11 : R=R'=Me); isoacronycine (20; R=R'=Me) was also produced. In an analogous manner the aminochromene (11 ; R=H. R'=Me) gave a mixture of des-N-methylacronycinc (7; R=H, RMe) and des-N-methylisoacronycine (20; R=H, R'=Me). The aminochromenes were best synthesised by condensation of lithio-5,7-dimethoxy-2,2-irnethylchromene (22; R=Li) with N-methylisatoic anhydride (26) or with 2-methyl-3.1-benzoxazm-4-one (21).The relevance of this synthetic route to the biogenesis of acridone alkaloids is discussed. |
