第一部分、2-醯基-1,3-環己雙酮之烯醇酯異構化及 其反應機構的研究 一系列2-醯基-1,3-環己雙酮的製備與其行成相對應的烯醇酯類異構化反應機構的研究。此遷移的驅動力很可能是由本身2-醯基上的氧原子與1,3-環己雙酮上的兩個氧原子發生靜電力排斥而導致其烯醇酯的平面變形進而提高了其烯醇化與隨後的異構化反應。 第二部分、對羥苯丙酮酸雙氧?抑制劑之設計與合成 設計合成一系列3-Hydroxy-4-(2-nitrophenyl)-(5H)-furanone衍生物30、31、32，經由分光光度烯醇硼酸鹽測定法分析其對對羥苯丙酮酸雙氧?（4-HPPD）之活性。化合物30、31、32的IC50值分別為8 μM、18 μM、20 μM，雖然其抑制效果並不如預期般的理想，很可能是苯環鄰位上的硝基對酵素活化位置有較高的立體障礙所導致。 I. Isomerization of Enol Esters Derived from 2-Acyl-1,3- cyclohexanediones: Mechanism and Driving Force A series of 2-acyl-1,3-cyclohexanediones were prepared and isomerization mechanisms of the corresponding enol esters were investigated. The driving force for this migration is likely that the intrinsic electrostatic repulsion between the 2-acyl oxygen atom and the two 1,3-diketone oxygens caused deformation of enol esters from planarity and resulted in their high susceptibility to enolization and subsequent isomerization. II. Design and Synthesis Inhibitors of 4-Hydroxyphenyl- pyruvate Dioxygenase A series of 3-Hydroxy-4-(2-nitrophenyl)-(5H)-furanone derivatives (30, 31, 32) have been designed, synthesized, and evaluated for in vitro inhibition activity against 4-hydroxyphenylpyruvate dioxygenase (4-HPPD) from pig liver by the spectrophotometric enol-borate method. Their IC50 value to part of 8, 18 and 20 μM. The IC50 value is not expected to our which may be 2-nitrophenyl group caused.
