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【答案】应助回帖
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爱与雨下: 金币+2 2012-05-17 21:34:53
sltmac: 金币+50, 翻译EPI+1 2012-05-31 08:52:15
修改后的：
Abstract
Mitsunobu reaction has become a powerful method for the introduction of novel functional groups such as C-O, C-N, C-S and C-C bonds, and it provides several advantages such as work-up procedure, shorter reaction time, milder conditions and high yield. At the same time, with the chiral alcohols taking part in a chemical reaction, the absolute configuration of the chiral carbon linked to alcoholic hydroxyl groups will reverse in the product. Since it was discovered in 1967 by Professor Oyo Mitsunobu, this reaction has been widely used in the total synthesis of various natural products and transformtaion of the functional groups. The thesis consists of the following three parts:
First part focuses on the recent development of the Mitsunobu reaction, including the Mitsunobu reaction to construct the chemical bonds of C-O, C-C, C-N and C-S, as well as its application in the total synthesis of natural products and drugs.
Chapter 2 mainly studies the application of the Mitsunobu reaction in the selective alkylation. Catechol compounds such as 3,4-dihydroxybenzaldehyde, methyl 3,4-dihydroxybenzoate, methyl gallate and 3,4-dihydroxy benzonitrile have been used as substrates reacting with benzyl alcohol, allyl alcohol, methanol, butanol, phenethyl alcohol and 4-methoxybenzyl alcohol under Mitsunobu reaction conditions for selective alkylation, which gave a series of single alkylation products with yields more than 70%. The structures of the products were confirmed by NMR, MS and IR. The results indicate that this method is bestowed with several merits , such as simplicity in operation, high conversions and yields, short reaction time and milder conditions. This novel method proved feasible in synthesis of the regioselectively alkylated catechols derivatives.
In chapter 3, a concise and efficient route for the total synthesis of natural chalcone 42 and 43 was presented. We have synthesized the intermediate 33 by Mitsunobu reaction from 2',4'-dihydroxyacetophenone. The single alkylation product 8 was obtained from 3,4-dihydroxy benzaldehyde. Then compound 33 reacted with compound 8 giving the desired product 42 via the base-catalyzed condensation. The compound 41 was synthesized from the 4-hydroxybenzoate through Mitsunobu reaction. Target product 43 was obtained from compounds 33 and 41 by the alkali-catalyzed condensation. |
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