介绍了丙二酰氧基硼氢化钾的制备及其原位与烯烃的选择性硼氢化.The preparation of potassium malonyloxyborohydride in situ and its selective hydroboration alkene are described.叙述了丙二酰氧基硼氢化钠的制备及其原位与烯烃的选择性硼氢化反应.The preparation of sodium malonyloxyborohydrid...
She looked up some friends of bygone years.她去看望了一些过去的老朋友。The room had the elegance of a bygone era.这个房间有着旧时代的优雅.The ferry service of bygone days has been replaced by that tunnel.往日的渡口已被那个隧道取代....