| 摘要 |
Substd. 4H-pyran derivs. of formula (I) and their salts are new: A = 3-6C cycloalkyl; or 1-8C alkyl; or 6-10C aryl or pyridyl opt. substd. up to three times by NO2, OH, COOH, CN, 6-10C aryl, halo, 3-6C cycloalkyl, CF3 or 1-6C alkyl, 1-6C alkoxycarbonyl, 1-6C alkylthio or 1-6C alkoxy or a group -O-CO-R5; R5 = 1-6C alkyl; R1, R2 = H, NH2, 1-8C alkyl, 1-8C alkoxy or 1-8C alkylamino; R3, R4 = 1-6C alkyl or 1-6C acyl. The following cpds. are excluded : 3,5-diacetyl-2,4,6-trimethyl-4H-pyran (Ia), 3,5-diethoxycarbonyl-2,6-dimethyl-4-phenyl-4H-pyran (Ib) and 3,5-diethoxycarbonyl-2,4,6-trimethyl-4H-pyran (Ic). |
