申请人:Sarawak Medichem Pharmaceuticals, Inc.
公开号:US20020013480A1
公开(公告)日:2002-01-31
The present invention relates to methods for preparing 2,2-dimethyl-5-acyloxy-10-propyl-2H,8H-benzo[ 1,2-b:3,4-b ′]dipyran-8-one (5) and 2,2-dimethyl-5-hydroxy- 10-propyl-2H,8H-benzo[1,2-b:3,4-b ′]dipyran-8-one (6) and their use as intermediates for the synthesis of antiviral calanolide compounds. For example, Fries rearrangement on compound
5
or Friedel-Crafts reaction on
6,
yields intermediate 2,2-dimethyl-5-hydroxy-6-propionyl-10-propyl-2H,8H-benzo[1,2-b:3,4-b′]dipyran-8-one (4), which, in turn, can be converted to (+)-calanolide A and (−)-calanolide B. The coupling of compound
6
with the appropriate chiral molecule under Mitsunobu or nucleophilic displacement leads to the asymmetric synthesis of antiviral calanolide compounds.
本发明涉及制备2,2-二甲基-5-酰氧基-10-丙基-2H,8H-苯并[1,2-b:3,4-b′]二吡喃-8-酮(5)和2,2-二甲基-5-羟基-10-丙基-2H,8H-苯并[1,2-b:3,4-b′]二吡喃-8-酮(6)的方法,以及它们作为抗病毒卡纳洛利德化合物合成的中间体的用途。例如,对化合物5进行Fries重排或对6进行Friedel-Crafts反应,得到中间体2,2-二甲基-5-羟基-6-丙酰基-10-丙基-2H,8H-苯并[1,2-b:3,4-b′]二吡喃-8-酮(4),进而可以转化为(+)-卡纳洛利德A和(-)-卡纳洛利德B。将化合物6与适当的手性分子在Mitsunobu或亲核取代下偶联,可实现抗病毒卡纳洛利德化合物的不对称合成。