A substituent directed regioselective synthesis of aryl/pyronyl pendant unusual adipate and tetrahydronaphthalene
作者:Ramendra Pratap、Vishnu Ji Ram
DOI:10.1016/j.tetlet.2008.02.148
日期:2008.4
efficient regioselective synthesis of pyronyl pendant ethyl methylthiocarbonylalkanoates 5 has been delineated from the base catalyzed reaction of suitably functionalized 2-pyranone 1 and 2-carbethoxycycloalkanones 2, 6 through successive substitution and regioselective ring opening by in situ generated mercaptide ion. To assess the effect of C-4 substituent on regioselectivity, reactions of 6-aryl
的有效区域选择性合成pyronyl挂件乙基methylthiocarbonylalkanoates 5已经从适当官能化的2-吡喃酮的碱催化反应划定1和2-carbethoxycycloalkanones 2,6通过连续置换和区域选择性开环原位产生的硫醇盐离子通过。为了评估C-4取代基对区域选择性的影响,6-芳基-3-氰基-4-(哌啶-1-基)-2-氧杂吡喃8与2-乙氧基环己酮6a和2-乙氧基-2-甲基环己酮6b的反应分别在类似的反应条件下进行分离,但分离出的化合物相同,其特征为4-芳基-8-甲基-2-哌啶-1-基-5,6,7,8-四氢萘-1-腈9。还通过碱催化2- [6-(4-溴苯基)-乙基的环转化而制备了2-(5-氨基-4'-溴-4,6-二氰基联苯-3-基)-5-甲基硫烷基羰基戊酸酯乙酯10。丙二腈在DMF中5-氰基3-氰基-2-氧代-2- H-吡喃-4-基] -5-甲基硫烷基羰基戊酸酯5d。