利用串聯雙基因分子生物技術，將治療基因接核糖體內切入點（IRES），再續接報導基因—單純疱疹病毒第一型-胸苷激酶基因（Herpes Simplex Virus 1-tymidine kinase gene,HSV1-tk gene），而整段基因由同一個啟動子（promoter）來控制。故當整段基因放入一載體（vector）殖入細胞組織，一旦受到啟動時，治療基因和報導基因會同時表達。124I-FIAU為一種PET基因分子影像探針能和報導基因---HSV1-tk gene最終經核糖體轉譯之激酶產物反應，所以經由124I-FIAU示踪造影可觀察生物體內HSV1-tk gene運作區域，間接得知治療基因在生物體內標靶細胞、組織或器官中是否運作。
本論文旨在合成基因探針124I-FIAU 之前驅物，FTAU ,(5-Tributylstannyl -1-(2-deoxy-2-fluoro-β-D-arabinofuranosyl)uracil) ，論文代號為產物(Ⅵ)，經由6個步驟已經成功合成出（參見圖1.合成流程），研究期間步驟1至6合成實驗累計共進行有36次。其中步驟3與步驟4改進文獻所報導的反應條件：步驟3必須接著步驟2進行，其最佳修改條件為加架分子篩的狀態下加熱廻流，步驟2維持150oC以上，步驟3維持71oC以上，最佳產率：40.05%，步驟4最佳修改條件為在加架分子篩的狀態下加熱廻流，廻流時間4小時50分，產率：72.95%。容易疏忽導致失敗的步驟：步驟1必須使用無水二氯甲烷，及加架分子篩，以提高產率。步驟6必須使用純的25%氨水與甲醇配合才能順利切除保護基，分離得到FTAU後要立即真空封管保存，且要低溫避光。最後實驗條件下對於1、3、4、5、6步的產率分別為：68.52%、40.05%、42.02%、32.14%、78.97%，累計總產率為2.9267%。

124I-FIAU is a PET scan gene probe for the reporter gene-HSV1-tk-gene. When one wants to make 124I-FIAU as a PET scan probe for a therapeutic gene，some molecular biologic technology such as double-gene construct should be employed. By the technology, two genes (therapeutic gene and reporter gene-HSV1-tk-gene) can be connected together via IRES and share the same promoter. When the constructed double-gene is placed in a vector such as virus and transfected into the targeted cell or tissue , therapeutic gene and HSV1-tk gene will express simultaneously, once initiated by the promoter. 124I-FIAU can react with thymidine kianse translated —HSV1-tk gene, and then retain in the targeted cell. Through tracing by 124I-FIAU and PET imaging, the motion of the reporter gene and consequently the active region of therapeutic gene can be observed.
This purpose of the thesis is to synthesize FTAU (5-Tributylstannyl -1-(2-deoxy-2-fluoro-β-D-arabinofuranosyl)uracil) which is the precursor of 124I-FIAU as a gene probe for HSV1-tk gene. Several steps of the synthetic procedure for FIAU are crucial and critical, the experiments have been repeated many times. The optimal conditions have been established by which the production yield can reach to a maximum. The synthetic scheme is shown in Fig. 1.For step1, one has to get rid of moisture by using dehydrated solvents and setting a molecular sieve. Since the product of step 2 is unstable, one has to conduct step 3 after step 2 as soon as possible. By keeping the reaction temperature at 150 oC at reflux in step 2, one can get the best production yield at step 3 : 40.05%.When the refluxing time is controlled at about 5 h., one can get a very high production yield at step 4 : 72.95%. For step 6 , one has to get rid of moisture so pure 25% ammonia must be used in the deprofection reaction . The whole yield can reach 2.93% by the synthetic procedure in accordance with the established optimal conditions.

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