Studies on the esterifications of 9-(hydroxyimino)-4-methyl-8,9-dihydrofuro[2,3-h]chromen-2-one with acid chlorides under different conditions

The esterifications of 9-（hydroxyimino）-4-methyl-8,9-dihydrofuro[2,3-h]chromen-2-one （4） with acid chlorides afforded normal oxime-esters 3a-e in 35-78% yields in presence of excessive 4-dimethylaminopyridine as the acid scavenger, whereas the reactions gave unexpected 8-substituted products N-（8-chloro-4-methyl-2-oxo-2H-furo-[2,3-h]chromen-9-yl）amides （5a-c） and 4-methyl-2,9-dioxo-8,9-dihydro-2H-furo[2,3-h]chromen-8-ylcarboxyloates （6d-e） by using excessive acid chlorides. The structures of 10 new compounds were determined by 1H NMR, 13C NMR, MS and HRMS, and the possible mechanism for the formation of unexpected products 5a--c and 6d-e was also proposed.

Expedient chemoselective and catalyst-free synthesis of 3,3-difluorochroman-4-ones from o-hydroxyarylenaminones and Selectfluor

An expedient and mild strategy for the synthesis of unconventional 2-（dimethylamino）-3,3-difluorochroman-4-one derivatives from o-hydroxyarylenaminones and Selectfluor was developed at room temperature under catalyst-free conditions. This method showed excellent chemoselectivity and great functional groups tolerance.

Visible-light induced cascade radical cyclization of sulfinic acids and o-(allyloxy)arylaldehydes towards functionalized chroman-4-ones

An efficient method for the synthesis of functionalized chroman-4-ones induced by visible light via the radical cyclization reaction of sulfinic acids and o-(allyloxy)arylaldehydes at room temperature was described.The corresponding products were isolated with moderate to good yields.Radical mechanism was proposed fo r this trans formation.Anti-microbial activity of some desired compounds we re screened.

麦冬中新成分二氢高异黄酮的研究

目的研究麦冬的化学成分。方法运用多种色谱方法进行分离纯化,根据理化性质和波谱数据鉴定化合物的结构。结果从麦冬80%乙醇提取物的乙酸乙酯萃取部分中分得3个化合物,分别鉴定为:5,7-dihydroxy-6,8-dimethyl-3-(3',4'-dihydroxybenzyl)chroman-4-one(Ⅰ)、5,7-dihydroxy-3-(4'-hydroxybenzyl)chromone(Ⅱ)和5,7-dihydroxy-6,8-dimethyl-3-(4'-dihydroxy-2',6'-dimethoxybenzyl)chroman-4-one(Ⅲ)。结论化合物I为一个新的高异黄酮类化合物,化合物Ⅱ为首次从麦冬中分离得到。

湖北麦冬地下部分化学成分

目的：研究百合科山麦冬属植物湖北麦冬Liriope spicata var.prolifera地下部分的化学成分,进一步丰富该植物的化学信息并为其开发和利用提供理论指导。方法：采用60%乙醇对湖北麦冬地下部分进行提取,综合利用大孔吸附树脂,正、反向硅胶,小孔树脂（MCI）及葡聚糖凝胶等柱色谱法对提取物进行分离和纯化,并根据化合物的理化性质及谱学数据鉴定其结构。结果：从湖北麦冬地下部分共分离并鉴定了12个化合物,其中包括4个黄酮类成分（化合物1~4）,4个酚类及苯甲酸类衍生物（化合物5~8）,2个酰胺类生物碱（化合物9,10）及2个其他类成分（化合物11,12）。分别鉴定为2＇,4,4＇-三羟基查耳酮（1）,木犀草素（2）,槲皮苷（3）,3,5-dihydroxy-7-methoxy-6-methyl-3-（4-hydroxybenzyl）chroman-4-one（4）,2,6-二甲氧基-4-硝基苯酚（5）,烯丙基焦儿茶酚（6）,3,4-dihydroxyallylbenzene 4-O-[α-L-rhamnopyranosyl（1→6）]-β-D-glucopyranoside（7）,丁香酸（8）,E-阿魏酰酪胺（9）,反式对羟基桂皮酸（10）,（1S,4S,5R,6R,7S,10S）-1,4,6-trihydroxyeudesmane-6-O-β-Dglucopyranoside（11）和5-羟甲基糠醛（12）。结论：其中化合物1~3,5~8及化合物10~12均为首次从山麦冬属植物中分离得到,化合物4和9为首次从该植物中分离得到。