New Results in the Synthesis of Styrylazulene Derivatives: Application of the ?Anil synthesis? to the preparation of azulenes substituted with styryl groups at the seven-membered ring
作者:Anne Andr�e Sophie Briquet、Hans-J�rgen Hansen
DOI:10.1002/hlca.19940770722
日期:1994.11.2
8-trimethylazulene (10) with 4b in toluene showed that azulenes can, indeed, be easily alkylated with the phosphonium salt 4b. 4,6,8-Trimethylazulene-2-carbaldehyde (12) has been synthesized from the corresponding carboxylate 15 by a reduction (LiAlH4) and dehydrogenation (MnO2) sequence (see Scheme 2). The Swern oxidation of the intermediate 2-(hydroxymethyl)azulene 16 yielded only 1,3-dichloroazulene derivatives
通过4,6,8-三甲基az烯-的Wittig反应,进行了4,6,8-三甲基-1-[(E)-4-R-苯乙烯基] azulenes 5(R = H,MeO,Cl)的合成。在沸腾的甲苯中在EtONa / EtOH存在下,1-甲醛(1)和相应的4-(R-苄基)(三苯基)phosph氯化物4(参见表1)。以相同的方式,愈创木烯-3-甲醛(2)以及二氢内塔拉维林(3)与4a分别产生了相应的苯乙烯基zu烯6和7(参见表1)。已经发现1和4b与Wittig反应竞争,得到的烷基化产物分别为8和9(参见方案1)。4,6,8-三甲基氮杂烯(10)与4b在甲苯中的反应表明,天青烯确实可以很容易地与the盐4b烷基化。通过还原(LiAlH 4)和脱氢(MnO 2)序列(参见方案2),由相应的羧酸盐15合成了4,6,8-三甲基氮杂-2-甲醛(12)。中间体2-(羟甲基)氮杂烯的Swern氧化16仅产生1,3-二氯氮杂