Total Synthesis Of Quinone And Hydroquinone And Study Of 3-substate γ-methylbutenolides And 3-substate γ-hydroxymethylbutenolides

The thesis aims at studying on the first total synthesis of 5-methyl-2-(2E, 6E-3, 7, 11-trimethyl-2, 6- dodecadien-9-onyl) benzo-1, 4-quinone and the corresponding hydroquinone, the synthesis of 3-substateγ-Methylbutenolides and 3- substateγ-hydroxylMethyl butenolides and reviews the process on theγ-Methylbutenolides. The whole of this thesis includes the following three parts.Chapter 1 First total synthesis of 5-methyl-2-(2E, 6E-3, 7, 11-trimethyl-2, 6- dodeca-dien-9-onyl) benzo-1,4-quinone and the corrresponding hydroquinoneThree natural occurring triprenylquinones and hydroquinones were isolated from endemic nudibranch Leminda millecra. The first total synthesis of 5- methyl -2 -(2E,6E-3,7,11- trimethyl-2,6-dodecadien-9-onyl)benzo-l, 4-quinone (12) and 5-methyl-2-(2E,6E-3,7,11-trimethyl -2, 6-dodecadien-9-onyl)-l, 4-hydroquinone (13) have been achieved from cheap and available 2-methylhydroquinone (15) and geranyl bromide, which involved protection of phenol, bromination, coupling reaction of aryl-bromide with Grignard reagent catalyzed by Li₂CuCl₄ , Julia coupling and etc. Reducing 12 with NaBH₄, one of this kind of natural products, 5-methyl-2- (2E, 6E-9-hydroxy-3, 7, 11-trimethyl-2, 6-dodecadienyl)-1, 4-hydroquinone (14) was obtained. The spectra data of synthetic compounds 12, 13, 14 were coincide with those of nature compounds.Chapter 2 Study towardγ-methylbutenolides andγ-HydroxymethylbutenolidesSection 1 The synthesis of natural (S)-3-(dodec-11-enyl)γ-methyl- butenolidesThe synthesis of natural (S)-3-(dodec-11-enyl)γ-methylbutenolides was accomplished from easily and available undec-10-enoic acid as starting material by eight steps, which involved Michael addition. Cyclization was achieved by the quantity oftetrabutyammoium fluoride. The overall yield was 16.8%.Section 2 Controlled Synthesis ofγ-Methyl andγ-Hydroxy-γ-methylbutenolidesUtilizing tetrabutylammonium fluoride as an effective condensation agentβ-Hydroxy -γ- OTBS pentanoate esters are deprotected in the presence of tetrabutylammonium fluoride to give eitherγ-methylbutenolides orγ-hydroxy -γ- methylbutenolides, depending on the quantity of the tetrabutyammoium fluoride. The mechanism of the formation ofγ-methyl andγ-hydroxy-γ-methylbutenolides is proposed. This methodology can be applied to the convenient synthesis of naturalγ-methyl andγ-hydroxy-γ-methylbutenolides. Section 3 The study toward (S)-3((S, E)) -5-hydroxy-3-enyl-γ- MethylbutenolidesTwo routes of (5)-3((S, E)) -5-hydroxy-3-enyl-γ- methylbutenolides were designed. 1) The rearrangement product 54 was achieved from easily available pentane-1, 5-diol as starting material which involved protection, bromination, Wittig reaction, selective protection 2°alcohol and oxidation. 2) The Key intermediate 59 was achieved from easily available cyclopentene as starting material by five steps, which involved oxidation by ozone, protection by ethane-1,2-diol, coupling reaction. Cyclization was also achieved by the quantity of tetrabutyammoium fluoride. At the same time, the model route was accomplished to test the feasibility and find the better solvent for the reaction.Chapter 3 Advance in the products of 3-Substate-γ- MethylbutenolidesThe 3-substate-5 (S) -methyl-2 (5H)-furanone is a large family of tropical and subtropical trees and shrubs comprising about 120 genera and more than 2000 species. Motivated by their promising potential as new antitumor drugs and other biological activities such as cytotoxic, insecticidal, antimalarial, antimicrobial, immuneosu-ppressive effects and so on, more and more chemists and biologists have now been interested in these compounds. Based on literature, the paper summarized the structures and various approaches to construct the skeleton of this kind of nature products. 139 references were quoted.