Method of preparing 2,6,10-Trimethyl-1,1-dialkoxy-3,5,9-undecatriene used as an intermediate of lycopene
申请人:Zhang Pengfei
公开号:US09051254B2
公开(公告)日:2015-06-09
The present invention describes a novel synthetic method for preparing the key intermediate 2,6,10-trimethyl-1,1-dialkoxy-3,5,9-undecatriene of lycopene. An existing synthetic method have some disadvantages that it is very difficult to gain the raw material dialkyl 4-methyl-5,5-diakoxy-1-pentene-1-phosphonate (10) because no effective synthetic method can be adopted, and furthermore the obtained target compound is composed of several cis/trans isomers. This invention relates to a process comprising a condensation step wherein a starting C10-phosphonate is changed to its carbanion completely at a temperature of −40˜30 under an atmosphere of a non-reactive gas in an organic solvent catalyzed by base, and then C4-dialkyl is added to undergo Wittig-Horner condensation. This invention affords all trans C14-acetal and this method is characterized with the advantages of simple procedure, easy access to raw material and low cost, which makes it has the value of industrial application.
本发明描述了一种新的合成方法,用于制备番茄红素的关键中间体2,6,10-三甲基-1,1-二烷氧基-3,5,9-十一烯。现有的合成方法存在一些缺点,即很难获得原料二烷基4-甲基-5,5-二烷氧基-1-戊烯-1-膦酸二酯(10),因为没有有效的合成方法可供采用,而且所得到的目标化合物由几个顺反异构体组成。本发明涉及一种工艺,其中在非反应性气氛下,以有机溶剂为催化剂的碱催化下,将起始C10-膦酸酯在温度为-40℃至30℃下完全转化为其碳负离子,然后加入C4-二烷基进行威特希格-霍纳缩合反应。本发明提供全部反式C14-缩醛,该方法具有工艺简单、原料易得和成本低等优点,具有工业应用价值。