3-Carbomethoxy-1(3H)-isobenzofuraneme(9)과 .alpha., .beta.-불포화 에스테르 화합물 3a-b를 각각 반응시켜서 naphthacene-6, 7-dione 11a-b를 좋은 수율로 얻었다. 이들 중 C-9 위치에 에틸기가 없는 11a는 산화시켰을 때 naphthacene-5, 12-dione 13a가 생성되는 반면, 에틸기를 갖고 있는 11b는 naphthacene-5, 7, 12-trione 12b와 naphthacene-5, 12-dione 13b가 3:2로 생성되어졌다.
3-Carbomethoxy-1(3H)-isobenzofuranone(9) underwent condensation with ${alpha}{eta}-unsaturated$, esters 3a-b to produce the corresponding naphthacene-6,7-diones 11a-b with high yields in one pot procedure. Among the naphthacene-6,7-diones formed, compound 11a without an ethyl group at C-9 position was oxidized to give the naphthacene-5,12-dione 13a, while compound 11b containing the ethyl group was oxidized to give a 3:2 mixture of the naphthacene-5,7,12-trione 12b and naphthacene-5,12-dione 13b under the same experimental conditions.
