Organic Synthesis by the Use of the Electrochemically Generated Active Zero-valent Tin Reagent

采用电解还原法和铝促进还原法研究了活性零价锡试剂的生成和循环使用，考察了四种反应类型，在MeOCH_2CH_2 OH-H_2 O-AcoH体系中，锡促进的紫罗兰酮的电化学加氢二聚反应; 2）SnCl_2促进的溴甲基丙烯酸与醛的外亚甲基内酯化反应; 3）Al-SnCl_2- 4）Al-SnCl_2促进的溴代酮与醛在无水DMF中催化量乙酸存在下的立体控制Aldol反应2体系具有明显的催化活性，使该试剂在水溶液中能插入到肉桂酰氯中，而不会使肉桂酰氯水解。

The generation and recycle use of the active zero-valent tin reagent have been investigated by the electroreduction and aluminum-promoted reduction.Four types of reactions ahbeen examined, namely1) Tin-promoted electrochemical hydrodimerization of ionones2) SnCl_2-promoted -exomethylenelactonization of bromomethylacrylic acid with alhdeydes in an MeOCH_2CH_2OH-H_2O-AcoH system3) Al-SnCl_2-promoted hydroxymethylation of allyl chlorides in aqueous THF4) Al -SnCl_2-promoted stereocontrolled aldol reaction of -bromoketones with aldehydes in dry DMF in the presence of a catalytic amount of acetic acidThe zero-valent tin generated by Al-SnCl_2 system was found to be markedly active so that the reagent can insert to cinamyl chloride in aqueous solution without hydrolysis of the cinnamyl chloride.