Synthesis of Pyranobenzopyran Derivatives as a Potent Antibacterial Agent

3-Formyl-4-hydroxy-2H(1)-benzopyran-2-one 1a-d on reaction with diethyl malonate in the presence of piperidine give ethyl-2H,5H-2,5-dioxopyrano[3,2-c] benzopyran-3-oate. 2a-d. Michael addition of 2a-d with ethyl aceto acetate gives ethyl 2,4-dihydroxy-5H, 12H- 5,12-dioxo [2] benzo pyrano [4,3-c] [1] benzopyran- 1-oate (3a-d). 3a-d on Pechmann condensation with ethyl aceto acetate gives 2-acetyl-1,6-dihydroxy-3H,7H,14H-3,7,14-trioxo-pyrano[2/,3/,5,6] [2] benzo pyrano [3,2-c] benzopyran 4a-d. Michael addition followed by cyclisation of acetyl acetone with ethyl-2H,5H- 2,5-dioxo-pyrano[3,2-c] benzopyran-3-oate 2 a-d in the presence of sodium methoxide in boiling methanol afforded1- acetyl-2-methyl-4H,5H,12H,4,5,12-trioxo-dipyrano[3,4-d;3/,2/-c] benzopyran. 5a-d. 마이클 첨가반응을 사용하여 ethyl 2,4-dihydroxy-5H, 12H- 5,12-dioxo [2] benzo pyrano [4,3-c] [1] benzopyran- 1-oate(3a-d)을 합성하였다. 3a-d와 베크만 축합반응물과 아세토 아세트산 에틸은 2-acetyl-1,6-dihydroxy-3H,7H,14H- 3,7,14-trioxo-pyrano[2/,3/,5,6][2] benzo pyrano[3,2-c] benzopyran(4a-d)이 되었다. 메톡사이드나트륨의 존재하에 끓는 메탄올에서 마이클 첨가에 뒤이어 아세틸 아세톤의 고리화 반응으로 ethyl-2H,5H-2,5-dioxopyrano[3,2-c] benzopyran- 3-oate(2a-d)을 사용하여 1-acetyl-2-methyl-4H,5H,12H,4,5,12-trioxo-dipyrano[3,4-d;3/,2/-c] benzopyran(5a-d.)을 합성하 였다. KCI Citation Count: 0