CONVERSION OF RUSCOGENIN INTO 1-ALPHA-HYDROXYCHOLESTEROL AND 1-BETA-HYDROXYCHOLESTEROL DERIVATIVES - STRUCTURE ELUCIDATION BY COMPUTER-ASSISTED ANALYSIS OF THEIR LANTHANIDE-INDUCED NMR SHIFTS
CONVERSION OF RUSCOGENIN INTO 1-ALPHA-HYDROXYCHOLESTEROL AND 1-BETA-HYDROXYCHOLESTEROL DERIVATIVES - STRUCTURE ELUCIDATION BY COMPUTER-ASSISTED ANALYSIS OF THEIR LANTHANIDE-INDUCED NMR SHIFTS
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DOI：
10.1016/s0040-4020(01)92435-4
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发表时间：
1981-01-01
期刊：
影响因子：
2.1
通讯作者：
MECHOULAM, R
中科院分区：
文献类型：
--
作者：
NOAM, M;TAMIR, I;MECHOULAM, R
由于ruscogenin(1)的结构特征使其有资格作为1-羟基维生素D类似物的潜在起始材料，因此对其化学性质进行了研究。Ruscogenin被氧化为1-氧基衍生物2，其被还原为Ruscogenin(1)和1-epiruscogenin(3)的混合物。1和3通过Clemmensen还原分别转化为四醇12和四醇21，通过对甲苯磺酰氯和氢化铝锂连续处理进一步还原为三醇15和25以及二醇16和24。三醇15还原成二醇[胆-5-烯-1 - β]。3. beta。-二醇是通过1号和3号位置的选择性苯甲酰化和16号位置的甲基化，然后进行LAH还原得到的。研究了转移试剂Eu(dpm)3[三（二氯甲烷酸）铕]测定产物结构的应用。诱导的位移是羟基的位置和取向的特征，可以促进羟基化类固醇结构的阐明。
The chemistry of ruscogenin (1) was studied since its structural features qualify it to serve as a potential starting material for 1-hydroxy vitamin D analogs. Ruscogenin was oxidized to the 1-oxo-derivative 2 which was reduced to a mixture of ruscogenin (1) and 1-epiruscogenin (3). Both 1 and 3 were converted by Clemmensen reduction to the respective tetrols 12 and 21, which were further reduced to the triols 15 and 25 and diols 16 and 24 by consecutive treatment with p-toluenesulfonylchloride and LAH [lithium aluminum hydride]. The reduction of triol 15 to diol [cholest-5-ene-1.beta., 3.beta.-diol was achieved by selective benzoylation of positions 1 and 3, and mesylation of position 16 followed by LAH reduction. The utility of the shift reagent Eu(dpm)3 [tris(dipivalomethanate)europium] to determine the structures of the products was studied. The shifts induced are characteristic of the position and orientation of the OH groups and can facilitate the elucidation of the structures of hydroxylated steroids.