Synthesis of Parvisoflavones A and B.
作者:Masao TSUKAYAMA、Yasuhiko KAWAMURA、Hiroto TAMAKI、Tokunaru HORIE
DOI:10.1248/cpb.39.1704
日期:——
Parvisoflavone B (2', 4', 5-trihydroxy-2", 2"-dimethylpyrano[5", 6"-g]isoflavone) (2) was synthesized by regioselective reduction of 7-[2, 4-bis(benzyloxy)phenyl]-2, 3-dihydro-5-methoxy-2, 2-dimethyl-4H, 6H-benzo[1, 2-b : 5, 4-b']dipyrano-4, 6-dione (7) with sodium borohydride and dehydration of the resultant alcohol, followed by dealkylation with boron trichloride. Its angular isomer, parvisoflavone A (2', 4', 5-trihydroxy-2", 2"-dimethylpyrano[6", 5"-h]isoflavone) (1) was also synthesized from 3-[2, 4-bis(benzyloxy)phenyl]-8, 9-dihydro-5-methoxy-8, 8-dimethyl-4H, 10H-benzo[1, 2, -b : 3, 4-b']-dipyran-4, 10-dione (15) in a similar manner.
副黄酮 B (2',4',5-三羟基-2",2"-二甲基吡喃并[5",6"-g]异黄酮) (2) 是通过用硼氢化钠还原 7-[2,4-双(苄氧基)苯基]-2,3-二氢-5-甲氧基-2,2-二甲基-4H,6H-苯并[1,2-b :用硼氢化钠和所得醇脱水后,再用三氯化硼进行脱烷基反应,就得到了 4-(苄氧基苯基)-2, 3-二氢-5-甲氧基-2, 2-二甲基-4H, 6H-苯并[1, 2-b : 5, 4-b']dipyrano-4, 6-二酮(7)。它的角异构体对维黄酮 A(2',4',5-三羟基-2",2"-二甲基吡喃并[6",5"-h]异黄酮)(1)也是由 3-[2,4-双(苄氧基)苯基]-8,9-二氢-5-甲氧基-8,8-二甲基-4H,10H-苯并[1,2,-b :3,4-b']-二吡喃-4,10-二酮(15)的类似方法。