(3S,7aR)-6-bromo-7a-methyl-3-phenyl-2,3-dihydropyrrolo[2,1-b][1,3]oxazol-5-one | 177696-37-6

• 分子结构分类: 有机化合物 - 苯类化合物 - 苯和取代衍生物
• 英文名称: (3S,7aR)-6-bromo-7a-methyl-3-phenyl-2,3-dihydropyrrolo[2,1-b][1,3]oxazol-5-one
• CAS: 177696-37-6
• 化学式: C₁₃H₁₂BrNO₂
• 分子量: 294.148
• InChiKey: QAMJODMIBCZIDJ-DGCLKSJQSA-N

计算性质

• 辛醇/水分配系数(LogP)：
  2.2
• 重原子数：
  17
• 可旋转键数：
  1
• 环数：
  3.0
• sp3杂化的碳原子比例：
  0.31
• 拓扑面积：
  29.5
• 氢给体数：
  0
• 氢受体数：
  2

反应信息

• 作为反应物：
  描述：

  (R)-(+)-N-甲氧基甲基-N-(三甲基甲硅基)甲基-1-苯乙胺 、 (3S,7aR)-6-bromo-7a-methyl-3-phenyl-2,3-dihydropyrrolo[2,1-b][1,3]oxazol-5-one 在 三氟乙酸 作用下， 以 二氯甲烷 为溶剂， 反应 2.0h， 以99.5%的产率得到(1S,2R,5S,8S)-8-bromo-2-methyl-5-phenyl-10-[(1R)-1-phenylethyl]-3-oxa-6,10-diazatricyclo[6.3.0.02,6]undecan-7-one
  参考文献：
  名称：

  Single and Double Diastereoselection in Azomethine Ylide Cycloaddition Reactions with Unsaturated Chiral Bicyclic Lactams

  摘要：

  Double diastereoselectivity data were analyzed to provide insight into the structural features that influence pi-facial selectivity in 1,3-dipolar cycloadditions of chiral and achiral azomethine ylides to chiral, unsaturated bicyclic lactams. Three major steric contributions to the differences in stability (Delta Delta G(double dagger)) between competing cycloaddition transition states were identified. The first major set of steric interactions involve that between the dipoles and the substituents on the left hemisphere (R(2)) and concave faces of the bicyclic lactams. This effectively hindered both alpha- and beta-approaches in the nonextended transition states shown in Figure 1. The second major steric interaction was provided by the nonbonded interactions (i) between the R(1) angular substituent on the bicyclic lactam and the pi-system of the dipole as shown in Figures 3 and 4. This interaction was shown to be very significant, causing reversal in pi-facial attack of chiral and achiral dipoles when the angular substituent is changed from phenyl or methyl to hydrogen. The high diastereoselectivity observed now opens a route to highly substituted chiral, nonracemic pyrrolidines.

  DOI：

  10.1021/jo9600870
• 作为产物：
  描述：

  L-苯甘氨醇 以 甲苯 为溶剂， 生成 (3S,7aR)-6-bromo-7a-methyl-3-phenyl-2,3-dihydropyrrolo[2,1-b][1,3]oxazol-5-one
  参考文献：
  名称：

  Single and Double Diastereoselection in Azomethine Ylide Cycloaddition Reactions with Unsaturated Chiral Bicyclic Lactams

  摘要：

  Double diastereoselectivity data were analyzed to provide insight into the structural features that influence pi-facial selectivity in 1,3-dipolar cycloadditions of chiral and achiral azomethine ylides to chiral, unsaturated bicyclic lactams. Three major steric contributions to the differences in stability (Delta Delta G(double dagger)) between competing cycloaddition transition states were identified. The first major set of steric interactions involve that between the dipoles and the substituents on the left hemisphere (R(2)) and concave faces of the bicyclic lactams. This effectively hindered both alpha- and beta-approaches in the nonextended transition states shown in Figure 1. The second major steric interaction was provided by the nonbonded interactions (i) between the R(1) angular substituent on the bicyclic lactam and the pi-system of the dipole as shown in Figures 3 and 4. This interaction was shown to be very significant, causing reversal in pi-facial attack of chiral and achiral dipoles when the angular substituent is changed from phenyl or methyl to hydrogen. The high diastereoselectivity observed now opens a route to highly substituted chiral, nonracemic pyrrolidines.

  DOI：

  10.1021/jo9600870

文献信息

• Single and Double Diastereoselection in Azomethine Ylide Cycloaddition Reactions with Unsaturated Chiral Bicyclic Lactams
  作者：Andrew H. Fray、A. I. Meyers

  DOI：10.1021/jo9600870

  日期：1996.1.1

  Double diastereoselectivity data were analyzed to provide insight into the structural features that influence pi-facial selectivity in 1,3-dipolar cycloadditions of chiral and achiral azomethine ylides to chiral, unsaturated bicyclic lactams. Three major steric contributions to the differences in stability (Delta Delta G(double dagger)) between competing cycloaddition transition states were identified. The first major set of steric interactions involve that between the dipoles and the substituents on the left hemisphere (R(2)) and concave faces of the bicyclic lactams. This effectively hindered both alpha- and beta-approaches in the nonextended transition states shown in Figure 1. The second major steric interaction was provided by the nonbonded interactions (i) between the R(1) angular substituent on the bicyclic lactam and the pi-system of the dipole as shown in Figures 3 and 4. This interaction was shown to be very significant, causing reversal in pi-facial attack of chiral and achiral dipoles when the angular substituent is changed from phenyl or methyl to hydrogen. The high diastereoselectivity observed now opens a route to highly substituted chiral, nonracemic pyrrolidines.