炔丙基硫縮醛(酮)的烯化反應

The Olefination Reactions of Propargylic Dithioacetal

陳智偉(Chih-Wei Chen)

指導教授 ： 陸天堯

國立臺灣大學/理學院/化學研究所/碩士(2008年)

https://doi.org/10.6342/NTU.2008.10233

摘要

本篇論文圍繞在烷基取代炔丙基硫縮醛的新型態烯化反應，可分為兩部分進行探討。
在本實驗室先前的研究中發現，烷基取代炔丙基硫縮酮與正丁基鋰進行開環反應後，若是與羰基化合物反應，能夠以高產率、具位向選擇性的生成高炔丙基醇。這樣的結果顯示出了和先前苯基取代炔丙基硫縮醛的例子相反的選擇性。似乎是取代基效應所造成的影響，烷基取代基傾向生成高炔丙基醇，而苯基取代基造成傾向生成丙二烯醇。
第一部分，我們利用溫和的Mitsunobu條件將高炔丙基醇轉變為相對應的烯炔產物。由於使用了對於官能基有很大容忍度的Mitsunobu condition，所以對於強還原環境敏感的溴取代、腈基與酯基均可得到相對應的產物，甚至受保護的醇基與硫縮酮官能基也可以得到相對應的烯炔產物。在立體選擇性方面，在一般的例子中主要的得到E選擇性的烯炔產物。進一步增大烯上的取代基則可以得到Z選擇性的烯炔產物。利用如此的方式，也許還可以用來合成含烯炔的高分子。初步的前測試充分的表現出合成高分子的可能性。
第二部分，我們發展出一個便利且具有高度位向選擇性的方法來製備三取代碘化呋喃，由高炔丙基醇可以順利的得到2,4,5-三取代碘化呋喃。將高炔丙基醇與醋酸汞反應後，進一步加入碘試劑置換後，便能以中等至好的產率生成三取代碘化呋喃。其呋喃環上2號及4號位置的取代基乃源自於高炔丙基醇之炔丙基，5號位置的取代基乃源自於醇之偕位，故藉此方法合成之碘化呋喃化合物具有高度的位向選擇性。相較先前利用丙二烯醇中間體合成三取代碘化呋喃的方式具有不同的位向選擇性。

關鍵字

炔丙基硫縮醛 ； 高炔丙基醇

並列摘要

The new olefination methods of alkyl substituted propargylic dithioacetals are described in this thesis. It can be divided into two parts for discussions.
In previous results, Alkyl substituted propargylic dithioacetals treating with butyl lithium then were allowed to react with carbonyl compounds to form homopropargylic alcohol with high yields and highly regioselective. This result showed different selsctivity comparing with aryl substituted propargylic dithioacetals. It seemed that different regioselectivies arose from different substiuents. Alkyl substituted ones were prefer to form homopropargylic alcohol and aryl ones were prefer to form allenyl alcohol.
The first part, we used the mild Mitsunobu conditions transforming homopropargylic alcohol into corresponding enyne derivatives. Because of using Mitsunobu conditions, which have highly functional group tolerance, the strong reduction environments sensitive substituents, like bromine, ester, and cyano group, may go through the reaction smoothly. Even the protected alcohol moiety and dithioacetal moiety also can proceed in the reaction environments. The steoreselectiviy showed the E selectivity in most of cases and Z selectivity was presented in larger substituents like mesityl and 1-naphthyl. Further pretests of synthesizing polymers also showed the highly possibility of synthetic single molecular weigh polymers.
The second part, we have developed a convenient and highly-regioselective approach to synthesis of trisubstituted iodofurans. Treating homoparpargylic alcohols with mercury acetate following with iodine reagent can be smooth converted to 2,4,5-trisubstituted iodofurans in moderate to good yields. The substituents on 2 and 4 position of furan ring were derived from the propargylic part of homopropargylic alcohol, and the substituent on 5 position of furan ring was derived from the

並列關鍵字

propargylic dithioacetal ； homopropargylic alcohol

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