臺灣博碩士論文加值系統

本論文乃要介紹如何以自由基分子內環合反應,去合成天然生物鹼
(-)-supinidine及(+)-retronecine.論文中共分兩個部份,第一部份是討
論(-)-supinidine之合成,我們以(-)-pyroglutamic acid為起始物製
得(-)-supinidine,此合成的特點是保留(+)-pyroglutamic acid的對掌中
心到最後的天然物中,此外,合成的關鍵步驟為攜帶■基自由基化合物之環
合.第二部份乃是有關(+)-retronecine之合成探討,我們以(-)-malic
acid為起始物,企圖合成出(+)-retronecine之鏡像異構物,合成過程中,除
了移植malic acid的對掌中心到產物外,並希望利用此一既有的對掌中心
來控制其它對掌中心之建立,不過此一目標尚未能完滿達成,但已發展一些
方向可循.

This reseach was devided into two parts.In the first part, we
describe the synthesis of (-)-supinidine,using (-)-pyro
glutamic acid as starting material.In our strategy, the
chirality of (-)-pyroglutamic acid was successfully transfered
to (-)-supinidine.Moreover, the key step of our synthesis was
the use of sulfonyl free radical cyclizations to constract the
pyrrolizidine skeleton. In the second part,we described our
approach in the synthesis of (+)-retronecine.We used the
cheaper (-)-malic acid as starting material to synthesize the
mirror imiage of (+)-ret- ronecine to test our strategy.In our
approach, the chiral center of malic acid was retained in the
product.We also relied this chiral center to established a new
one.Although we did not finish the total synthesis of
(+)-retronecine,we have already established a viable route.