Study on Sunthesis and Characterization of New Polyenes Bearing Sulfur Functional Groups

作者首次合成了一些含有1，2-二(亚磺基)-或1-硒-2-亚磺基的4-烷氧基-1，3-丁二烯，作为4-碳同源反应的起始原料。用乙基溴化镁/原甲酸三乙酯处理苯基炔丙硫醚或硒化物，以较好的产率得到4-亚硫基或4-硒基-2-乙醛二乙缩醛。与醇钠异构化，再相继加入苯硫酸钠或亚硒酸钠，得到3，4-二(亚磺基)-或4-硒-3-亚磺基-3-烯醛二乙缩醛。缩醛的脱烷氧基反应只生成4-烷氧基丁二烯。接下来，我们尝试了我们通常的方法，包括Wittig类型的两步程序，使用4-烷氧基丁酸-1，3-二烯。1-苯基亚硫基-4-烷氧基丁酸-1，3-二烯与DABCO/n-BuLi或LTMP在1-位进行锂化合反应，与醛反应生成中等产率的戊二烯衍生物。酸促进的水合反应经环化反应得到5元环化合物，而5-2，4-二烯醛的产率较低。我们精确地研究了水合步骤和SOCl2/吡啶对五-2，4-二烯的形成是有效的。一些醛以较好的产率提供了五-2，4-二烯醛衍生物，但产品的立体选择性不好。我们还用4-烷氧基丁酸-1，3-二烯进行了醛的串联五-2，4-二烯基化反应。第二个五-2，4-二烯基化得到2，4，6，8-tetrakis(phenylsulfanyl)nona-2，4，6，8-tetraenal衍生物，该衍生物被分离出来作为其肼类化合物。现在，我们正在研究2，4，6，8-四烯酮的表征，特别是它的光化学行为。

The author originally prepared some 4-alkoxy-1,3-butadienes bearing 1,2-bis(sulfanyl)-or 1-selanyl-2-sulfanyl groups as starting materials of 4-carbon homologations. Treatment of the phenyl propargyl sulfides or selenides with ethyl magnesium bromide/triethyl ortho formate provided 4-sulfanyl or 4-selanylbut-2-ynal diethyl acetals in good yields. The isomerization with sodium alkoxide and the successive addition of sodium benzenethiolate or selenolate to give the 3,4-bis(sulfanyl)-or 4-selanyl-3-sulfanylbut-3-enal diethyl acetals. The dealkoxylation of the acetals exclusively formed the 4-alkoxybuta-1,3-dienes. Next, we tried our usual methodology consisting of the Wittig type two-step procedure, using 4-alkoxybuta-1,3-dienes. The lithiation of the 1-phenylsulfanyl-4-alkoxybuta-1,3-dienes proceeded at 1-position with DABCO/n-BuLi or LTMP and reactions with aldehydes provided the pentadienol derivatives in moderate yields. The acid-promoted hydration underwent cycization to give the 5-membered ring compounds ; however, the penta-2,4-dienals were obtained in low yields. We precisely investigated the hydration step and SOCl_2/pyridine found to be effective for formation of the penta-2,4-dienals. Some aldehydes provided the penta-2,4-dienal derivatives in good yields ; however, the stereoselectivities of the products are not good. We also performed the tandem penta-2,4-dienylation of the aldehydes using 4-alkoxybuta-1,3-dienes. The second penta-2,4-dienylation provided 2,4,6,8-tetrakis(phenylsulfanyl)nona-2,4,6,8-tetraenal derivative, which was isolated as its hydrazone derivatives. Now, we are investigating the characterization of the nona-2,4,6,8-tetraenals, especially the photo-chemical behaviors.