ABSTRACT A number of 5-siloxylated 1,1-diethoxy-3-alkyn-2-ones were prepared from the corresponding ketals. The t-butyldiphenylsiloxy derivatives were stable, whereas the trimethylsilyl analogs were unstable. The former compounds were reacted with diethylamine, lithium dimethylcuprate, and 1,3-propanedithiol and gave Michael adducts in good to very good yields. The amine and cuprate gave the conjugated
摘要 从相应的
缩酮制备了许多 5-甲
硅烷氧基化的 1,1-二乙氧基-3-炔-2-酮。叔丁基二苯基甲
硅烷氧基衍
生物稳定,而三甲基甲
硅烷基类似物不稳定。前一种化合物与
二乙胺、二甲基
铜酸
锂和
1,3-丙二硫醇反应,得到迈克尔加合物,收率很好。胺和
铜酸盐产生共轭的烯酮,前者以立体有择方式(Z),后者立体有择地(E)在一种情况下,但在其他情况下立体选择性地以 E 为优势。随着二
硫醇双加成发生,相应的
1,3-二噻烷以极好的收率获得。从
1,3-丙二硫醇和 1,1-diethoxy-4-diethylaminoalk-3-en-2-ones 制备 1,3-dithianes 的尝试失败了。图形概要