The present invention relates to a novel benzopyran or thiobenzopyran derivative represented by formula (1): pharmaceutically acceptable salt or stereoisomer thereof, in which X, R1, R2, R3, R4 and A are defined as described in the specification, and to a process for preparation thereof and a pharmaceutical composition having anti-estrogenic activity which contains the compound (1) as an active component.
precursors has been developed to construct sulfides, disulfides, selenides, sulfoxides and sulfones. Combining this deacylative process with SN2 or coupling reactions provides novel and convenient modular approaches toward unsymmetrical or symmetrical disulfides.
已经开发出一种使用无张力甲基酮作为自由基前体的温和光催化脱酰策略来构建硫化物、二硫化物、硒化物、亚砜和砜。将此脱酰过程与 S N 2 或偶联反应相结合,为不对称或对称二硫化物提供了新颖且方便的模块化方法。