(20R,23S,24R)-5α-dinosteran-29-ol tert-butyldimethylsilyl ether | 148459-78-3

• 英文名称: (20R,23S,24R)-5α-dinosteran-29-ol tert-butyldimethylsilyl ether
• CAS: 148459-78-3
• 化学式: C₃₆H₆₈OSi
• 分子量: 545.021
• InChiKey: LNUOGKBJNDZINA-RZDJGDRHSA-N

物化性质

• 沸点：
  545.0±19.0 °C(predicted)
• 密度：
  0.902±0.06 g/cm3(Temp: 20 °C; Press: 760 Torr)(predicted)

计算性质

• 辛醇/水分配系数(LogP)：
  11.24
• 重原子数：
  38.0
• 可旋转键数：
  8.0
• 环数：
  4.0
• sp3杂化的碳原子比例：
  1.0
• 拓扑面积：
  9.23
• 氢给体数：
  0.0
• 氢受体数：
  1.0

反应信息

• 作为产物：
  描述：

  (3S,8S,9S,10R,13S,14S,17S)-10,13-dimethyl-17-(2-methyl-1,3-dioxolan-2-yl)-2,3,4,7,8,9,10,11,12,13,14,15,16,17-tetradecahydro-1H-cyclopenta[a]phenanthren-3-ol 在 platinum(IV) oxide 吡啶 、 咪唑 、 N-甲基-4-哌啶酮 、 盐酸 、 六甲基磷酰三胺 、 sodium hydroxide 、 lithium aluminium tetrahydride 、 偶氮二异丁腈 、 n-Bu₄SnH 、 氨 、 氢气 、 双氧水 、 aluminum isopropoxide 、 lithium 、 potassium 2-methylbutan-2-olate 、 溶剂黄146 、 三乙胺 、 sodium iodide 、 diborane(6) 、 lithium diisopropyl amide 作用下， 以 四氢呋喃 、 正己烷 、 二氯甲烷 、 丙酮 、 苯 为溶剂， 反应 7.0h， 生成 (20R,23S,24R)-5α-dinosteran-29-ol tert-butyldimethylsilyl ether
  参考文献：
  名称：

  5α-地甾烷的C-23和C-24非对映异构体的合成

  摘要：

  制备C 30生物标记物5α-地甾烷（1）的C-23和C-24非对映异构体的立体选择路线涉及（20S）-20-（碘甲基）-4α-甲基-5α-孕烯（7）与3,4-二甲基戊酸甲酯饱和酯（9）结合，然后还原，主要得到赤型-非对映异构体或7，与α，β-不饱和酯3,4-二甲基戊烯酸甲酯烷基化（12）），然后还原，主要得到苏-非对映异构体。

  DOI：

  10.1016/0040-4039(93)88018-e

文献信息

• Synthesis of biological markers in fossil fuels. 7. Selected diastereomers of 4.alpha.-methyl-5.alpha.-stigmastane and 5.alpha.-dinosterane
  作者：Ivan Stoilov、Ewa Kolaczkowska、David S. Watt、Jan St. Pyrek、Robert M. K. Carlson、Frederick J. Fago、J. Michael Moldowan

  DOI：10.1021/jo00064a039

  日期：1993.6

  Efficient routes for the preparation of selected C-23 and C-24 diastereomers of the C30 biological markers 4alpha-methyl-5alpha-stigmastane (1) and 5alpha-dinosterane (2) involved the alkylation of 20-(iodomethyl)-4alpha-methyl-5alpha-pregnane with either saturated or alpha,beta-unsaturated esters. The alkylation of (20S)-20-(iodomethyl)-4alpha-methyl-5alpha-pregnane with methyl (3R)-3-ethyl-4-methylpentanoate furnished methyl (20R,23zeta,24S)-4alpha-methyl-5alpha-stigmastane-23-carboxylate, and a subsequent decarbomethoxylation provided (20R,24R)-l. The alkylation of (20S)-20-(iodomethyl)-4alpha-methyl-5alpha-pregnane with methyl (3S)-3,4-dimethylpentanoate led to methyl (20R,23zeta,24R)-4alpha,24-dimethyl-5alpha-cholestane-23-carboxylate, and the reduction of this mixture provided principally (20R,23S,24R)-5alpha-dinosteran-29-ol. The further reduction of the mesylate of this isomer secured (20R,23S,24R)-5alpha-dinosterane (2a). The application of the same sequence of reactions using methyl (3R)-3,4-dimethylpentanoate led principally to (20R,23R,24S)-5alpha-dinosterane (2d). The alkylation of (20S)-20-(iodomethyl)-4alpha-methyl-5alpha-pregnane with methyl (2zeta)-3,4-dimethyl-2-pentanoate and a subsequent reduction of the ester provided a separable mixture of (20R,23R)- and (20R,23S)-5alpha-dinoster-24-(28)-en-29-ol in a 2.4:1 ratio. The conversion of (20R,23R)-5alpha-dinoster-24(28)-en-29-ol to the corresponding tert-butyldimethylsilyl ether, reduction of the DELTA24(28) bond with hydrogen over platinum oxide, and deprotection gave principally (20R,23R,24R)-5alpha-dinosteran-29-ol. The further reduction of this alcohol provided (20R,23R,24R)-5alpha-dinosterane (2b). The application of the same sequence of reactions to (20R,23S)-5alpha-dinoster-24(28)-en-29-ol provided (20R,23S,24S)-5alpha-dinosterane (2c). Diastereoselectivity at the C-23 position in these ester alkylations was examined as a function of stereochemistry at both the C-20 and C-24 positions.