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刘灿灿烂阳光

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[求助] 求翻译,有些地方不太懂

A long-necked flask equipped with a rubber  septum was flame-dried and placed under argon atmosphere. To this a 0.66-1.99 M THF solution of LiAIH4 (filtered through dry Celite) was introduced via a syringe, and then at room temperature an alcohol in THF (2.00 M, 1 equiv) was added in a dropwise manner over a period of ca. 10 min with stirring. Subsequently a THF solution of optically pure binaphthol [(I?)- or (S)-1] (0.6 M, 1 equiv) was added dropwise, and the resulting mixture was stirred usually for an additional 30  min at room temperature  and used for the asymmetric reduction. Notably the BINAL-H reagent 3 (R'O = simple alkoxyl) thus formed in THF was cloudy but a near-solution which contained only a very small amount of suspension. If a large quantity ofprecipitate separates out for some reason, one should repeat the preparation from the beginning. Optically active binaphthol may racemize to some extent upon exposure
to strong acids or bases in protic media.14" Care should be exercised in its recovery in reusable form.  Decolorization of optically  active bi- naphthol by charcoal caused serious racemization。
大概意思都懂,主要是不太确定这些东西是怎么加进去,顺序什么的。。。
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刘灿灿烂阳光: 金币+5, 翻译EPI+1, 有帮助 2014-03-20 16:14:38
配有橡胶塞(隔片)的长颈烧瓶一个,火焰干燥然后放置在氩气中。0.66-1.99 M的LiAlH 4(通过干燥硅藻土过滤)的THF溶液通过注射器注入上述长颈烧瓶。然后在室温下,醇的THF(2.00 M,1当量)溶液以滴加方式加入长颈烧瓶,加液时长约 10分钟,同时搅拌。随后,光学纯的联萘酚[(I) - 或(S)-1]的THF溶液(0.6 M,1当量)逐滴加入,然后将所得混合物在室温下搅拌,通常再搅拌30分钟,然后用于不对称还原。值得注意的是:这样形成的THF BINAL-H试剂3(R'O=简单的烷氧基)是近似于只含有极少量的悬浮液的混浊液体。如果由于某种原因大量的沉淀物析出,制备方法应该从头开始重来。光学活性的联萘酚一定程度上可以外消旋化而暴露在 强酸或质子介质.14“。应注意,光学活性的联萘酚可重复使用的形式和如何重新使用。木炭造成的严重的外消旋化会使光学活性双萘酚脱色。
2楼2014-03-19 18:52:54
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