本論文研究分為兩部分，第一部分嘗試以ab initio分子軌域計算方法探討掩飾鄰苯?與單取代烯類的Diels-Alder反應，第二部分則是以ab initio分子軌域計算方法來探討掩飾鄰苯?與環戊二烯、?喃、?咯及?吩的Diels-Alder反應。
在第一部分中，我們分別探索乙烯、丙烯、甲基乙烯醚、丁烯酮以及丁二烯與掩飾鄰苯?間Diels-Alder反應之過渡結構。文中每一個過渡結構都分別分別以HF/3-21G、HF/6-31G*、MP2/3-21G及MP2/6-31G*進行幾何最佳化，並且以MP3與MP4SDQ計算單點能量，最高至MP4SDQ//MP2/6-31G*等級，同時也進行了電荷分佈分析。計算結果顯示，對於不同的親雙烯劑，過渡結構會有明顯不同的特質，而控制立體選擇及位向選擇的主導因素也隨之不同。

在第二部分中，我們亦分別探索環戊二烯以及?喃、?咯、?吩等雜環分子與掩飾鄰苯?間Diels-Alder反應之過渡結構。反應之過渡結構以及產物

這裡，所有的結構都以HF/3-21G做幾何最佳化，並且在MP4SDQ/6-31G*//HF/3-21G等級下做單能量計算。在這樣的計算等級下，主要的過渡結構都是以高度的非同步性進行協同反應，其中以環戊二烯、?喃以及?咯為親雙烯劑時，電荷轉移扮演了相當重要的角色。我們所尋找到的主要過渡結構則以intrinsic reaction coordinate (IRC)來確認與產物之關係。

雖然以?喃、?咯及?吩為親雙烯劑之[2+4]反應其活化能與主要的[4+2]反應活化能相當，但是經由計算所得之熱力學數數據分析，[2+4]反應之反應自由能過高，反應不會朝這方向進行。

In this thesis, ab initio molecular orbital theory was used to study the mechanisms of the Diels-Alder reaction of masked o-benzoquinone with mono-substituted alkenes, followed by the Diels-Alder reactions of the masked o-benzoquinone with cyclopentadiene, furan, pyrrole and thiophene.
In the first section, the transition structures of each Diels-Alder reaction by the masked o-benzoquinone with ethylene, propene, methyl vinyl ether, methyl vinyl ketone and butadiene, were optimized individually, using HF/3-21G, HF/6-31G*, MP2/3-21G and MP2/6-31G* levels of theories. The single-point energetics employing the aforementioned optimized geometries were done using MP3 and MP4SDQ methods. The highest level of energy calculation utilized was MP4SDQ//MP2/6-31G*. The charge distribution of each species was also analyzed. The result showed that the different properties exist in each transition structure of these Diels-Alder reactions with each dienophile, and lead to different dominant control of stereo-selectivities and regio-selectivities in the reaction mechanisms.

In the second section, the transition structures of each Diels-Alder reaction by the masked o-benzoquinone with the heterocyclics, such as furan, pyrrole and thiophene, were optimized individually, at the level of HF/3-21G, followed by the single-point energy calculation at MP4SDQ/6-31G* level. The results showed that the most transition structures process highly asynchronous concerted reaction. The charge transfer dominates while the cyclopentadiene, furan and pyrrole act as the dienophiles. The main transition structures obtained by the calculations were reconfirmed using intrinsic reaction coordinate (IRC) method. According to the thermodynamic data analysis, the free energies of the [2 + 4] reactions are too large to make the reactions spontaneous although in the [2 + 4] reactions in which furan, pyrrole and thiophene act as the dienophiles, the activation energies are equivalent to those of the main [4 + 2] reactions.

Diels, O.; Alder, K. Ann., 1928, 460, 98.
Liao, C.-C.; Chu, C.-S.; Lee, T.-H.; Rao, P. D.; Ko, S.; Song, L.-D.; Shiao, H.-C. J. Org. Chem. 1999, 64, 4102.
Gao, S.-Y.; Lin, Y.-L.; Rao, P. D.; Liao, C.-C. Synlett 2000, 421.
陳建興博士論文，國立清華大學，台灣新竹市，2000.
Arjona, O.; Medel, R.; Plumet, J. Tetrahedron Lett. 1999, 40, 8431.
Houk, K. N.; Li, Y.; Evanseck, J. D. Angew. Chem. Int. Ed. Engl. 1992, 31, 682.
Houk, K. N.; Gonzalez, J.; Li, Y. Acc. Chem. Res. 1995, 28, 81.
PC Spartan, v 1.5, Wave Function, Inc., 18401 Von Karman, Suite 370, Irvine, CA 92715.
Schmidt, M. W.; Baldridge, K. K.; Boatz, J. A.; Jensen, J. H.; Koseki, S.; Matsunaga, N.; Gordon, M. S.; Ngugen, K. A.; Su, S.; Windus, T. L.; Elbert, S. T.; Montgomery, J.; Dupuis, M. J. Comput. Chem. 1993, 14, 1347.
Alex A. Granovsky, http://classic.chem.msu.su/gran/gamess/index.html
Baker, J.; Kessi, A.; Delley, B. J. Chem. Phys. 1996, 105, 192.
Jorgensen, W. L.; Lim, D.; Blake, J. F. J. Am. Chem. Soc. 1993, 115, 2936.8
Houk, K. N.; Loncharich, R. J.; Blake, J. F.; Jorgensen, W. J. J. Am. Chem. Soc. 1989, 111, 9172.
Bach, R. D.; McDouall, J. J. W.; Schegel, H. B. J. Org. Chem. 1989, 54, 2931.
Bachrach, S. M., Liu, M. J. Org. Chem. 1992, 57, 6736.
Bachrach, S. M. J. Org. Chem. 1994, 59, 5027.
Jursic, B.; Zdravkovski, Z. J. Chem. Soc. Perkin Trans. 2 1995, 1223.
Li, Y.; Houk, K. N. J. Am. Chem. Soc. 1993, 115, 7478.
Andersson, G. Acta Chem. Scand. B 1976, 30, 403
Jorgensen, W. L.; Lim, D.; Blake, J. F. J. Am. Chem. Soc. 1993, 115, 2936.
Froese, R. D. J.; Organ, M. G.; Goddard, J. D.; Stack, T. D. P.; Trost, B. M. J. Am. Chem. Soc. 1995, 117, 10931.
Garcia, J. I.; Martinez-Merino, V.; Mayoral, J. A.; Salvatella, L. J. Am. Chem. Soc. 1998, 120, 2415.
Ruiz-Lopez, M. F.; Assfeld, X.; Garcia, J. I.; Mayoral, J. A.;Salvatella, L. J. Am. Chem. Soc. 1993, 115, 8780.
Jorgensen, W. L.; Lim, D.; Blake, J. F. J. Org. Chem. 1994, 59, 803.
Garcia, J. I.; Mayoral, J. A.; Salvatella, L. Tetrahedron 1997, 53, 6057.
(a) Wenkert, E.; Moeller, P. D. P.; Pierttre, S. R. J. Am. Chem. Soc. 1988, 110, 7188. (b) Wenkert, E.; Pierttre, S. R. J. Org. Chem. 1988, 53, 5850.
Sugiyama, S.; Tsuda, T.; Mori, A.; Takeshita, H.; Kodama, M. Bull. Chem. Soc. Jpn. 1987, 60, 3633.
Jung, M. E.; Street, L. J.; Usui, Y. J. Am. Chem. Soc. 1986, 108, 6810.
Hamadait, H.; Neeman, M. Israel Patent 9749, 1957; Chem. Abstr. 1958, 52, 1263e.
(a) Seitz, G.; Kaempchen, T. Chem. Ztg. 1975, 99, 292. (b) Seitz, G.; Kaempchen, T. Arch. Pharm. 1978, 311, 728. (c) Seitz, G.; Mohr, R. Chem. Ztg. 1987, 111, 81.
(a)許岱欣碩士論文，國立清華大學，台灣新竹市，1997. (b) Hsu, D.-S.; Rao, P. D.; Liao, C.-C. Chem. Commun. 1998, 1795.
Chen, C.-H.; Rao, P. D.; Liao, C.-C. J. Am. Chem. Soc. 1998, 120, 13254.
Rao, P. D.; Chen, C.-H.; Liao, C.-C. Chem. Commun. 1999, 713.
謝明芳博士論文，國立清華大學，台灣新竹市，2000.
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