报道了以钯(II)为催化剂的咔唑分子间直接乙酰氧基化反应的通用高效方法.以醋酸钯为催化剂,过硫酸钾为氧化剂,2-吡啶磺酰基作为导向基团,以85％和83％的收率合成单乙酰氧基化和双乙酰氧基化产物.结构经1 H NMR,13 C NMR,IR和HR-MS(ESI)表征.

A new method for the synthesis of 8-hydroxyisocoumarin is reported. 8-Hydroxyisocoumarin was synthesized from Meldrum's acid by Friedel-Crafts acylation, carbonyl protection, ester reduction and deprotection. The key intermediate 3-ethynyl-2-(hydroxymethyl)cyclohex-2-en-1-one was synthesized by acidic cycloaddition, aromatization of cyclohexanone ring and 2,3-dicyano-5,6-dichlorobenzoquinone (DDQ) oxidation. The structures were characterized by 1 H NMR, 13 C NMR, IR, and HRMS.

The total synthesis of natural products pulchrol and pulchral with antiprotozoan activity was reported, starting from the cheap hydroquinone and 4-methylbenzoic acid and using palladium-catalyzed intramolecular decarboxylation coupling reaction of arene carboxylic acids with aryl bromides as the key reaction. This method provides an opportunity for further study of the structure-activity relationship.

以苯甲醛和2,4,6-三羟基苯乙酮一水合物为起始原料,经C-异戊烯基化、氧化环化、碘甲烷保护羟基、羟醛缩合反应以及催化关环等步骤,以7.2％和5.7％的总收率实现了两个天然吡喃类黄酮obovatachalcone和(±)-obovatin methyl ether的全合成,其结构经1 H NMR,13 C NMR,IR和HR-MS(ESI)确证.

以廉价的香草醛,3,4-二羟基苯甲醛和2,4,6-三羟基苯乙酮为初始原料,经过C-香叶基化、羟基保护、羟醛缩合、脱去保护基以及催化环化等步骤,以11％和20％的总收率实现了两个天然香叶基黄烷酮(±)-diplacone与(±)-3'-O-methyldiplaone的首次全合成,其结构经1 H NMR,IR和MS表征.

以香草酮和对羟基苯甲醛为原料,经酚羟基保护、羟醛缩合、相转移催化法接糖、去保护基等反应合成了两个天然查尔酮苷——4'-O-β-D-喃葡萄基-3'-甲氧基-4-甲氧基-碴尔酮和4'-Oβ-D-喃葡萄基-3'-甲氧基-4-羟基童尔酮,总收率分别为17.2％和20.8％,其结构经1H NMR,13C NMR和HR-MS确证.在脱保护基反应中,首次提出了NH4Cl脱除MOM保护基的新方法.

以2,4-二羟基苯乙酮为原料,经C-异戊烯基化和酚羟基保护制得中间体2-羟基-4-甲氧甲氧基-3,5-二异戊烯基苯乙酮(4).以对羟基苯甲醛为原料,经C-异戊烯基化和催化环化制得中间体2,2-二甲基-5-甲酰基-2H-1-苯并吡喃(7);4和7经羟醛缩合反应得2'-羟基-3',5'-二异戊烯基-4'-甲氧甲氧基-4,5-(2,2-二甲基-苯并吡喃)-查尔酮(8);8经分子内的迈克尔加成反应得6,8-二异戊烯基-7-甲氧甲氧基-4',5'(2,2-二甲基-苯并吡喃)-二氢黄酮(9);在对甲苯磺酸的催化下,9脱去保护基,首次完成了天然异戊烯基黄烷酮(±)-LespeflorinsA3的全合成.其中8和9为新化合物,其结构经1H NMR,IR和EL-MS表征.

The total synthesis of natural product chalcone derivative,1,2-Dihydroparatocarpin A,was first synthesized in total yield of 21.8% by C-prenylation,protection of phenolic hydroxyl group,aldol condensation,cyclization of DDQ and cyclization of the p-toluenesulfonic acid catalyted from 4-hydroxybenzaldehyde and 2,4-dihydroxyacetophenone.The structures were confirmed by 1H NMR,IR and MS.

A new compound,3,4',6'-tri[( methoxy) methoxy]-4-methoxy-2'-hydroxy-3'-( 3″-methylbut-2″-enyl) chalcone( 6),was prepared by alkylation and condensation from 3-[( methoxy) methoxy]-4-methoybenzaldehyde and 4,6-bis[( methoxy) methoxy]-2-hydroxy-3-( 3″-methylbut-2″-enyl)acetophenone. A new compound,( ±)-5,7,3'-tri[( methoxy) methoxy]-4'-methoy-8-( 3″-methylbut-2″-enyl) flavanone( 7),was prepared by cyclization of 6. Two naturally occurring isoprenyl flavanoids,( ±)-5,3'-dihydroxy-7,8-( 2,2-dimethyl pyrano)-4'-methoxy flavanone( 1) and( ±)-5,7,3'-trihydroxy-4'-methoxy-8-( 3″-methylbut-2″-enyl) flavonone( 2) were synthesized in total yield of11. 6% and 10. 5% by deprotection and cyclization from 7. 1 was first synthesized and the structures were characterized by1H NMR,IR and MS.

以2,4-二羟基苯乙酮和2,4-二羟基苯甲醛为起始原料,经过C-异戊烯基化、保护酚羟基、羟醛缩合、去保护基反应首次成功地完成了天然产物3″,3″-二甲基吡喃[3’,4’]2,4,2’-三羟基查尔酮的全合成,总产率18.4%,其结构经1H NMR,IR和MS表征。中间体8未见文献报道。

The total synthesis of natural product Coryfolia D was first achieved from 3,4-dihydroxybenzaldehyde and 2,4-dihydroxyacetophenone by C-prenylation,protection of phenolic hydroxyl group,aldol condensation,cyclization and DDQ dehydrogenation deprotection in total yield of 11.8%.The structures were characterized by 1H NMR,IR and MS.

A facile approach for the first total synthesis of naturally occurring geranylated flavanoids sepicanin A has been obtained with total yield 16% starting from 2,4,6-trihydroxyacetophenone after four steps.The key step was the protic acids(HCl or p-TsOH)-catalyzed benzopyrone formation in a protic polar solvent by deprotection and cyclization of chalcone in one step.All structures of new compounds were confirmed by IR,1H NMR and MS.

The total synthesis of (+/-)-5,3'-dihydroxy-4'-methoxy-6 '',6 ''-dimethyl-chromeno-(7,8,2 '',3 '')-flavanone was first achieved through C-prenylation, cyclization, selective protection of phenolic hydroxyl group, aldol condensation, cyclization and deprotection starting from cheap isovanillin and 2,4,6-trihydroxyacetophenone, with total yield 6.7%. All structures of new compounds were confirmed by IR, H-1 NMR, MS and FIRMS techniques.

A facile approach for the total synthesis of prenylated flavonoids, (+/-)-abyssinone-VI-4-O-methyl ether (1), (+/-)-abyssinone-IV-4'-O-methyl ether (2), (+/-)-abyssinone-V-4'-O-methyl ether (3) and (+/-)-sigmoidin E (4), has been described. The key intermediate 4-hydroxy-3,5-di-(3-methylbut-2-enyl)benzaldehyde (6) was synthesized that features regioselective prenylation of 4-hydroxybenzaldehyde and crystallizing with petroleum ether from the reaction mixture by freeze-out effect. All structures of new compounds were confirmed by IR, H-1 NMR, MS and HRMS techniques.

The total synthesis of natural Paratocarpin B was first achieved through C-prenylation,protection of phenolic hydroxyl group,aldol condensation,cyclization and deprotection from 4-hydroxy-benzaldehyde and 2,4-dihydroxyacetophenone in total yield of 18.4%.Intermediate 10 was new compound.The structures of new compounds were characterized by 1H NMR,IR and MS.