Satoh Tsuyoshi, Sakamoto Tatsuya, Watanabe Masanori, Takano Koji
Department of Chemistry, Faculty of Science, Tokyo University of Science, Kagurazaka, Shinjuku-ku, Tokyo 162-8601, Japan.
Chem Pharm Bull (Tokyo). 2003 Aug;51(8):966-70. doi: 10.1248/cpb.51.966.
Treatment of 1-chlorovinyl p-tolyl sulfoxides, which were synthesized from ketones and chloromethyl p-tolyl sulfoxide, with ethylmagnesium chloride or isopropylmagnesium chloride at below -78 degrees C gave magnesium alkylidene carbenoids in about 90% yields. The reaction of the generated carbenoids with lithium alpha-sulfonyl carbanions was found to afford tri- and tetra-substituted allenes. Both cyclic ketones and acyclic ketones were useful in this procedure. However, the 1-chlorovinyl p-tolyl sulfoxides derived from aldehydes gave only rearranged products, acetylenes, under the reaction conditions. The magnesium alkylidene carbenoid derived from an optically active 1-chlorovinyl p-tolyl sulfoxide was treated with lithium alpha-carbanion of 1-naphthyl phenyl sulfone; however, the obtained allene was found to be racemic. The mechanism of this reaction is also discussed.
由酮与对甲苯基亚磺酰氯甲基合成的1-氯乙烯基对甲苯基亚砜，在低于-78℃的条件下用乙基氯化镁或异丙基氯化镁处理，可得到产率约为90%的亚烷基卡宾镁化合物。发现生成的卡宾化合物与α-磺酰基碳负离子锂反应可得到三取代和四取代的丙二烯。环状酮和非环状酮在此过程中均有用。然而，由醛衍生的1-氯乙烯基对甲苯基亚砜在反应条件下仅得到重排产物乙炔。将由光学活性的1-氯乙烯基对甲苯基亚砜衍生的亚烷基卡宾镁化合物用1-萘基苯基砜的α-碳负离子锂处理；然而，发现得到的丙二烯是外消旋的。还讨论了该反应的机理。
