A simple and versatile synthesis of 3-methylidenechroman-2-ones and 2-methylidenedihydrobenzochromen-3-ones has been developed. The reaction of phenols or naphthols with 3-methoxy-2-diethoxyphosphorylacrylate gave intermediate 3-diethoxyphosphorylchromen-2-ones or 2-diethoxyphosphorylbenzo-chromen-3-ones, respectively. These compounds were employed as Michael acceptors in the reaction with Grignard reagents to yield 4-substituted 3-diethoxyphosphorylchroman-2-ones or 1-substituted 2-diethoxyphosphoryldihydrobenzochromen-3-ones. The obtained adducts were next used as Horner-Wadsworth-Emmons reagents for the olefination of formaldehyde to give the final products.
已经开发出一种简单且多功能的合成3-
甲叉基色满-2-酮和2-甲叉基二氢苯并色满-3-酮的方法。将
酚或
萘酚与3-甲氧基-2-二乙氧基
磷酸丙烯酸酯反应,分别得到中间体3-二乙氧基
磷酸色满-2-酮或2-二乙氧基
磷酸苯并色满-3-酮。这些化合物作为迈克尔受体与
格氏试剂反应,生成4-取代的3-二乙氧基
磷酸色满-2-酮或1-取代的2-二乙氧基
磷酸二氢苯并色满-3-酮。所得加合物随后用作霍纳-沃兹沃思-埃蒙斯试剂,与
甲醛进行烯化反应,得到最终产物。