Synthesis of Azabenzisochromanequinone Antibiotics, II: 9(6)-Hydroxy-6(9)-Azabenzisochromanequinones via Aminoisochromanes and Meldrum's Acid
作者:Carsten Tödter、Helmut Lackner
DOI:10.1055/s-1997-1222
日期:1997.5
The synthesis of 6(7)-amino-5,8-dimethosyisochromanes 7,8, precursors of the B-C ring system of benzisochromanequinone antibiotics 1, is described. Subsequent N-alkylation using Meldrum's acid/trimethyl orthoformate followed by a high temperature cyclization and oxidative demethylation yields 9(6)-0-demethyl-6(9)-azaeleutherins 13 and 6(9)-azaepinanaomycin A methyl esters 14. The novel aza-analogues allowed further studies on the structure-activity relations in the field of (aza)benzisochromanequinone antibiotics.