L(+)propylene glycol.
L(+)propylene glycol.
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L()丙二醇。
DOI：
10.1021/ja01182a049
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发表时间：
1948
影响因子：
15
通讯作者：
H. Fischer
中科院分区：
文献类型：
--
作者：
E. Baer;H. Fischer
丙二醇的两种对映异构体的制备和性质先前已经描述。左旋型是（a）用钠在乙醇和甲苯中还原D-乳酸乙酯得到的，1（B）用亚硝酸钾2或亚硝酸银使左旋的1-氨基丙醇-2盐酸盐脱氨基得到的，3· 4（c）通过用氢氧化钠6水解顺式环氧丙烷或用甲酸和盐酸6水解左旋环氧丙烷和（d）通过植物化学还原丙酮醇。7· 8反旋式丙二醇是由反旋式环氧丙烷与甲酸和盐酸水解而得。6· 6通过上述方法获得的两种对映体的比旋光度变化很大。很明显，这些方法大多数产生顺旋和左旋丙二醇的混合物，其比例取决于起始原料的光学纯度和当时的实验条件。我们有一种方法可以得到纯的丙二醇对映体，并揭示它们与立体化学中公认的甘油醛的立体关系。之所以决定用这种方法制备左旋丙二醇，是因为这种异构体还没有像左旋化合物那样纯的光学状态，而左旋化合物已经有一种很好的生物化学制备方法。[7]顺便说一下，这种选择也允许使用更容易获得的d-甘露醇作为起始原料。本文概述了合成1（+）丙二醇的反应顺序和有关化合物的空间相互关系。
The preparation and the properties of both en-antiomers of propylene glycol have been previously described. The levo-rotatory form has been obtained (a) by reduction of ethyl D-Iactate with sodium in ethanol and toluene, 1 (b) by desamina-tion of the levo-rotatory l-aminopropanol-2 hydrochloride with potassium nitrite2 or silver nitrite, 3· 4 (c) by hydrolysis of dextro-rotatory propylene oxide with sodium hydroxide6 or hy-drolysis of levo-rotatory propylene oxide with formic acidand hydrochloric acid6 and (d) by phytochemical reduction of acetol. 7· 8 The dextro-rotatory form of propylene glycol has been obtained by hydrolysis of dextro-rotatory propylene oxide with formicand hydrochloric acid. 6· 6 The specific rotations of both enantiomers obtained by the above methods vary greatly. It is obvious that most of these procedures producemixtures of the dextro-and levo-rotatory propylene glycol, the ratio depending on the optical purity of the start-ing material and the prevailing experimental con-ditions.We had at our disposal a method which was ex-pected to yield the pure enantiomers of propylene glycol and to reveal their steric relationship to glyceraldehyde, the accepted compound of refer-ence in stereochemistry. It was decided to prepare by means of this method the dextro-rotatory propylene glycol because this isomer had not yet been obtained in as pure an optical state as the levo-rotatory compound for which an excellent biochemical method of preparation already ex-isted. 7 Incidentally, this choice also permitted the use of the much more readily available d-mannitol as starting material. The sequence of reactions employed in the synthesis of l (+) pro-pylene glycol and the steric interrelationship of the various compounds concerned are outlined in the reaction scheme.