（一）、不同介質對於γ-基-α,β-不飽和硫代酯基與1,3-環戊二烯之Diels-Alder反應之影響研究（二）、骨架上含二個及三個氧原子之含氧籠狀化合物之合成研究

Abstract

本論文將順式親二烯基2b在不同介質中與1,3-環戊二烯進行Diel-Alder反應，若在含有β-CD的水溶液進行反應，則可以將endo產物4b與eXo產物5b的比例增進至>99:<1。 將反式親二烯基３與1,3-環戊二烯進行Diels-Alder反應，會產生化合物６與化合物７立體方位不同之加成產物，其立體構造可經由碘環化反應加以確認。其中化合物7b與化合物7c在進行碘環化反應同時亦會進行硫代甲醚基之重排反應，得到產物25b與25c，其中化合物25b立體構造可由X-ray單體繞射光譜加以確定。 將反式親二烯基３在不同介質中與1,3-環戊二烯進行Diels-Alder反應，實驗結果發現若是在含有路易士酸的二氯甲烷溶液中，在-78℃條件下進行反應，則可以將endo-醯基之產物６與endo-硫代甲酯基之產物７的比例增進至99:1。 本論文分別對bis-endo-γ-keto thioester, bis-endo-γ-keto ester及bis-endo-1,4-dione取代基之[2.2.1]庚烯衍生物，經由碘環化反應關鍵步驟，可合成出骨架含有三個氧之籠狀化合物，其中籠狀化合物36立體構造可由X-ray單體繞射光譜加以確定。 將endo加成產物51經由碘環化反應關鍵步驟，可合成出骨架含有三個氧之母體籠狀化合物55。 將1, 4-對苯酉昆衍生物與1, 3-環戊二烯及1, 3-環己二烯進行Diels-Alder反應，將其所產生的endo加成產物，使用NaBH4-CeCl3試劑進行立體選擇性還原反應，再將此產物進行碘環化反應，最後加入KH試劑再吹進行環化反應，我們也能成功合成出含有兩個氧與一個雙鍵之籠狀化合物。 而將含碘之籠狀化合物74和98加入強鹼KH脫去一分子HI，就可合成出其有相當大環張力的三角環之籠狀化合物其立體結構可能如76及106所示。化合物7b及106之結構尚待做化學驗證來加以確定。 將1, 4-對笨酉昆衍生物與兩當量1, 3-環戊二烯進行Diels-Alder反應，將其所產生的endo-anti-endo加成產物81，使用的NaBH4試劑加以還原，再此產物進行碘環化反應，就可合成出具有對稱性之雙籠狀化合物86。

Diels-Alder reaction of the cis-isomer 2b with cyclopentadiene in various media are investigated. In β-CD aqueous solution, the endo/exo ratio can be increased up to 99:1. Diels-Alder reaction of the trans-isomer 3 with cyclopentadiene gave the cycloadducts 6 and 7, which stereochemistry was confirmed by chemical transformations such as reaction and iodocyclization reaction. Iodocyclization of 7b and 7c gave the methylthio group rearranged products 25b and 25c, which structure was proven by X-ray analysis of the crystalline compound 25b. Diels-Alder reaction of 3 with cyclopentadiene in the presence of Lewis acids at -78 ℃ gave the endo-acyl product 6 exclusively. Diacetal trioxa-cages where synthesized from norbornene derivatives of 2,3-bis-erirfo-γ-keto thioesters, 2,3-bis-endo-γ-keto esters and 2,3-bis-endo-l,4-diones by utilizing a novel sequential iodocyclization reaction as the key step. The structure of the trioxa-cages was proven by X-ray analysis of the crystalline compound 36. The unsubstituted (parent) compound of trioxa-cages 55 was synthesized from the cyclopentadiene maleic anhydride cycloadduct 51 in a short sequence. Dioxa-cage compounds were synthesized from the Diels-Alder cycloadducts of 1,4-benzoquinones with cyclopentadiene and cyclohexadiene in a short sequence via reduction with NaBH4-CeCl3, iodocyclization reaction, followed by treatment with KH in dryTHF. Treatment of compounds 74 and 98 with KH in dry THF gave compounds 76 and 106 whose structures are tentatively assigned. The structure of 76 and 106 need to be confirmed by futher chemical proof. Diels-Alder reaction of 1, 4-benzoquinone with two equivalents of cyclopentadiene 86 was synthesized from 81 via reduction with NaBH4 and iodocyclization reaction.