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This article includes two chapters: an important intermediate for the synthesis of the first chapter of a natural product of Lake neomycin (Lactonamycin); the important intermediates second chapter Ascomycone A synthesis research. In this paper, the two natural products, inverse synthetic analysis, design a viable synthetic routes and important intermediates Click Directions successful synthesis of the desired product. Chapter 1: In this paper, through Step 6 and Step 10 Lake the neomycin important intermediates 10 and 21 construction complete reaction to the 16.8% and 10.3% of the total yield. First, propargyl alcohol is protected with dihydropyran to give compound 3 in 84.1% yield. After Birch reduction to give compound 6 diene terephthalic dimethyl ether as raw material, and Compound 4, followed by Diels-Alder, and occurs at 190 ℃ retroDiels-Alder adduct, and compound 8 was obtained in a yield of 41.3%. After ethyl acetate LDA process carbanion 8 nucleophilic addition, the smooth was obtained in a yield of 68.9% of the compound 9, followed by the 9 CAN oxidation, oxidation yield of 98% completion of the synthesis of the compound 10; to methyl acetoacetate as a starting material, the compound 12.12 through enolate TMS protection obtained Compound 13 is obtained in 89% yield with the bromo-maleic anhydride Diels-Alder adduct occurs after acetylation, to give Compound 14, Next, 14 L-Selectride reduction to give compound to 15,15 then after NBS bromoacetate to give 17a, 17b and 17c, the separation requires 17a, 56% yield. After the study of the multi-step reaction, the successful pot synthesis of compound 20. Subsequently, 20 enolate, TBS protection Lake neomycin Another important intermediates 21, a yield of 91.5%. Chapter II: Research Ascomycone A synthesis of important intermediates. Analysis of inverse synthetic designed two reasonably synthetic route. In the first route to the 2,5 - dimethoxybenzaldehyde as a starting material, obtained through glycol protective quantitative compound 26,26 bromination occurs, Compound 27 was obtained in 86% yield. Deprotection then to 27, and then through the bistriphenylphosphine dichloride palladium catalyzed Sonogashira cross-coupling reaction, to give 3,6 - dimethoxy -2 - (1 - propynyl-yl) benzaldehyde 29, iodide the cuprous catalyzed ring-closing reaction of the compound 29, obtained in a yield of 24.5% Intermediate 30; for good control of the structure of the target product, we designed a second route. With 2 - chloro-4 - methoxy-phenol as a starting material, to give the product 34, with paraformaldehyde reaction, followed by etherification, oxidation, and then after propanediol protection, a high yield of compound 37 was obtained. Departure from 37 constructed in accordance with the route a synthetic intermediate 40. Acetoacetic acid methyl ester as raw materials obtained after the two-step reaction Danishefsky diene 43. Work in progress 40 off ring after CAN oxidized quinone, then prepared with 43 pot legal system target product.
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