Eleven aldehydes (6a-1) were synthesized by 1-carbon homologation of ketones and aldehydes according to the following sequence: Horner-Emmons reaction of 2-(O,O-dimethylphosphonyl)-1,3-benzodithiole (1)and various carbonyl compounds (2) to give benzo-1,4-dithiafulvenes (3); reduction with sodium borohydride and tetrafluoroboric acid-ether complex in dry acetonitrile to 1,3-benzodithioles (5); subsequent hydrolysis of these with mercury(II)oxide and aqueous tetrafluoroboric acid (35%) in tetrahydrofuran. The procedure is simple, of wide application, and afforded pure aldehydes in good overall yields (55-88%).
通过1-碳同系化合成11种醛(6a-1),其合成路线如下:2-(O,O-二
甲基膦酰基)-1,3-苯并二
硫酚(1)与各种羰基化合物(2)进行Horner-Emmons反应,得到苯并-1,4-二
硫富烯(3);在无
水乙腈中用
硼氢化钠和四
氟硼酸-醚络合物还原为1,3-苯并二
硫酚(5);接着在
四氢呋喃中用氧化
汞和35%的四
氟硼酸水溶液进行
水解。该方法简便、适用广泛,最终以较高总收率(55-88%)得到纯净的醛。