Spirocyclopropane compounds. V. One-step synthesis of 5-acetylspiro(benzofuran-2(3H),1'-cyclopropan)-3-one.
作者:MASAZUMI WATANABE、MITSURU KAWADA、MASAYUKI TAKAMOTO、ISUKE IMADA、SHUNSAKU NOGUCHI
DOI:10.1248/cpb.32.3373
日期:——
5-Acetylspiro [benzofuran-2 (3H), 1'-cyclopropan]-3-one (3a, AG-629), previously found to be the most potent antiulcer compound in a series of spirocyclopropanes, was obtained by onestep synthesis starting from methyl 5-acetyl-2-[(tetrahydro-2-oxo-3-furanyl) oxy] benzoate (1a). In this reaction, 5, 10'-(diacetyl-5', 6'-dihydrospiro [benzofuran-2 (3H), 4'(3'H)-[2H] oxocino [3, 2-b]-benzofuran]-3-one (5a), which has a new ring system, and 1H, 3H-8-acetyl-4, 5-dihydronaphtho [1, 2-c : 4, 3-b'] difuran-1-one (6) were isolated as by-products. A possible reaction mechanism is presented.
5-乙酰基螺[苯并呋喃-2(3H), 1'-环丙烷]-3-酮(3a,AG-629),在一系列螺环丙烷中被发现是最有效的抗溃疡化合物,是通过从甲基5-乙酰基-2-[(四氢-2-酮-3-呋喃)氧]苯甲酸酯(1a)的一步合成获得的。在该反应中,分离出了具有新环系统的5, 10'-(二乙酰基-5', 6'-二氢螺[苯并呋喃-2(3H), 4'(3'H)-[2H]氧基-希诺[3, 2-b]-苯并呋喃]-3-酮(5a)和1H, 3H-8-乙酰基-4, 5-二氢萘[1, 2-c : 4, 3-b']二呋喃-1-酮(6)作为副产物被分离出来。提供了一种可能的反应机制。