Synthesis of (±)-<i>trans</i>-7,8-Dihydrodiol of 6-Fluoro-benzo[<i>a</i>]pyrene via Hydroxyl-Directed Regioselective Functionalization of Substituted Pyrene
作者:Barbara Zajc
DOI:10.1021/jo9819178
日期:1999.3.1
Synthesis of (+/-)-trans-7,8-dihydroxy-6-fluoro-7,8-dihydrobenzo[a]pyrene, the metabolite from 6-fluoro-benzo[a]pyrene, is described. Position 6 of 7,8,9,10-tetrahydrobenzo[a]pyren-7-ol (1) was functionalized by bromination with N-bromosaccharin. Regioselectivity in the bromination is thought to derive from a substrate-reagent hydrogen bond. NMR evidence is offered to support this model. The 6-bromo
描述了(+/-)-反式-7,8-二羟基-6-氟-7,8-二氢苯并[a] py的合成,该代谢物是由6-氟-苯并[a] py制成的。通过用N-溴糖精溴化,将7,8,9,10-四氢苯并[a] py-7-醇(1)的6位官能化。认为溴化中的区域选择性源自底物-试剂氢键。提供了NMR证据来支持该模型。对6-溴衍生物2进行脱水,然后进行溴-锂交换。用NFSi淬灭硫代中间体,得到6-氟衍生物4。在7,8双键上的Prévost反应产生反式二苯甲酸酯5(通过与通过四氧化顺式二羟基化制备的顺式衍生物比较而建立)。通过溴化-脱氢溴化程序引入9,10双键,然后进行水解,