(E)-4-(tert-Butyl-diphenyl-silanyloxy)-pent-2-enoic acid tert-butyl ester | 194367-41-4

• 分子结构分类: 有机化合物 - 脂质和类脂质分子 - 脂肪酰基
• 英文名称: (E)-4-(tert-Butyl-diphenyl-silanyloxy)-pent-2-enoic acid tert-butyl ester
• CAS: 194367-41-4
• 化学式: C₂₅H₃₄O₃Si
• 分子量: 410.629
• InChiKey: KAVSESTXTZZNHC-VHEBQXMUSA-N

计算性质

• 辛醇/水分配系数(LogP)：
  4.85
• 重原子数：
  29.0
• 可旋转键数：
  6.0
• 环数：
  2.0
• sp3杂化的碳原子比例：
  0.4
• 拓扑面积：
  35.53
• 氢给体数：
  0.0
• 氢受体数：
  3.0

反应信息

• 作为反应物：
  描述：

  (E)-4-(tert-Butyl-diphenyl-silanyloxy)-pent-2-enoic acid tert-butyl ester 在 吡啶 、 正丁基锂 、 lithium diisopropyl amide 作用下， 反应 4.83h， 生成 (2S,3S,4S)-2-((R)-1-Acetoxy-ethyl)-3-benzylamino-4-(tert-butyl-diphenyl-silanyloxy)-pentanoic acid tert-butyl ester
  参考文献：
  名称：

  Highly Diastereoselective Conjugate Addition of Lithium Dialkylamides to α,β-Unsaturated Esters Having a Chiral Center at the γ-Position

  摘要：

  The conjugate addition of lithium amides 2 to tert-butyl 4-(OR)-substituted-2-pentenoates 1 produced a mixture of the syn-and anti-amino esters (3 and 4) in high yields. Sterically bulky OR groups, such as trityloxy and tert-butyldiphenylsilyloxy, gave the syn diastereomer 3 either exclusively or predominantly. The syn-selectivity may be explained by a modified Felkin-Anh model. The use of tert-butyldimethylsilyloxy as an OR group afforded a nearly 1:1 mixture of diastereoisomers, and the use of the smallest MeO group produced a 63:37 mixture of the syn 3 and anti isomer 4. The presence of Me group at the alpha-position (C-2 position) of the enoate enhanced the syn diastereoselectivity up to 100%; the conjugate addition to tert-butyl 4-methoxy-2-methyl-2-pentenoate (17) gave the syn-isomer 18 exclusively. This enhancement may be explained by the combination of chelation and allylic strain model 19 in which the smallest H orients inside to avoid an allylic strain. A phenyl group at the gamma-position enhanced the anti selectivity in the case of gamma-alkoxy-alpha,beta-enoates such as isopropyl 4-[(tert-butyldimethylsilyl)oxy]-4-phenyl-2-buteonoate (20), and in the case of gamma-alkyl-alpha,beta-enoates such as tert-butyl 4-phenyl-2-pentenoate (27).

  DOI：

  10.1021/jo970435d
• 作为产物：
  描述：

  叔丁基二苯基氯硅烷 在 咪唑 、 正丁基锂 、 sodium hydride 、 二异丁基氢化铝 作用下， 以 二氯甲烷 、 甲苯 为溶剂， 反应 6.33h， 生成 (E)-4-(tert-Butyl-diphenyl-silanyloxy)-pent-2-enoic acid tert-butyl ester
  参考文献：
  名称：

  Highly Diastereoselective Conjugate Addition of Lithium Dialkylamides to α,β-Unsaturated Esters Having a Chiral Center at the γ-Position

  摘要：

  The conjugate addition of lithium amides 2 to tert-butyl 4-(OR)-substituted-2-pentenoates 1 produced a mixture of the syn-and anti-amino esters (3 and 4) in high yields. Sterically bulky OR groups, such as trityloxy and tert-butyldiphenylsilyloxy, gave the syn diastereomer 3 either exclusively or predominantly. The syn-selectivity may be explained by a modified Felkin-Anh model. The use of tert-butyldimethylsilyloxy as an OR group afforded a nearly 1:1 mixture of diastereoisomers, and the use of the smallest MeO group produced a 63:37 mixture of the syn 3 and anti isomer 4. The presence of Me group at the alpha-position (C-2 position) of the enoate enhanced the syn diastereoselectivity up to 100%; the conjugate addition to tert-butyl 4-methoxy-2-methyl-2-pentenoate (17) gave the syn-isomer 18 exclusively. This enhancement may be explained by the combination of chelation and allylic strain model 19 in which the smallest H orients inside to avoid an allylic strain. A phenyl group at the gamma-position enhanced the anti selectivity in the case of gamma-alkoxy-alpha,beta-enoates such as isopropyl 4-[(tert-butyldimethylsilyl)oxy]-4-phenyl-2-buteonoate (20), and in the case of gamma-alkyl-alpha,beta-enoates such as tert-butyl 4-phenyl-2-pentenoate (27).

  DOI：

  10.1021/jo970435d