trans-1-bromo-4-methyl-5-ethylcyclopentene | 96689-50-8

• 分子结构分类: 有机化合物 - 有机卤素化合物 - 乙烯基卤化物
• 英文名称: trans-1-bromo-4-methyl-5-ethylcyclopentene
• 英文别名: trans-1-bromo-5-ethyl-4-methylcyclopentene；(4R,5S)-1-bromo-5-ethyl-4-methylcyclopentene
• CAS: 96689-50-8
• 化学式: C₈H₁₃Br
• 分子量: 189.095
• InChiKey: ANFAFGMTZYOYAM-RQJHMYQMSA-N

计算性质

• 辛醇/水分配系数(LogP)：
  3.3
• 重原子数：
  9
• 可旋转键数：
  1
• 环数：
  1.0
• sp3杂化的碳原子比例：
  0.75
• 拓扑面积：
  0
• 氢给体数：
  0
• 氢受体数：
  0

反应信息

• 作为反应物：
  描述：

  trans-1-bromo-4-methyl-5-ethylcyclopentene 在 18-冠醚-6 、 碘 、 叔丁基锂 、 potassium hydride 作用下， 以 四氢呋喃 为溶剂， 反应 25.25h， 生成 (2R,3S,3aS,5aR,9aR,9bS)-3-Ethyl-2,5,5-trimethyl-1,2,3,3a,5,5a,6,7,9a,9b-decahydro-cyclopenta[a]naphthalen-4-one
  参考文献：
  名称：

  Diastereoselectivities Associated with the 1,2-Addition of Chiral (Racemic) Cyclopentenyl Organometallics to Bicyclo[2.2.2]octenones

  摘要：

  The levels of diastereoselection attainable during condensation of the bicyclo[2.2.2]octenones 5-7 with organometallics derived from a selection of the vinyl bromides 8-12 have been determined. The 1,2-additions involving 6 exhibit excellent molecular recognition (>98:2) during syn (endo) addition to the carbonyl group. The diastereoselectivities associated with the capture of 5 and 7 are lower and more variable, although still respectable in several examples. In all cases, the dominant product is the alcohol in which the C-5 substituent on the nucleophilic subunit is beta-oriented. The structural assignments to the numerous alcohols follow from correlations of olefinic carbon chemical shifts, X-ray crystallography in selected examples, and anionic oxy-Cope rearrangement to generate polycyclic ketones whose stereochemical features were defined by NMR methods. The findings provide insight into the transition State geometries adopted in the course of these reactions. The model which has been formulated is consistent with the greater discriminatory power of 6 and conforms closely to earlier proposals for related reactions.

  DOI：

  10.1021/jo00087a017
• 作为产物：
  描述：

  trans-4-methyl-5-ethyl-1-(trimethylstannyl)cyclopentane 在 溴 作用下， 以 二氯甲烷 为溶剂， 反应 0.25h， 以92%的产率得到trans-1-bromo-4-methyl-5-ethylcyclopentene
  参考文献：
  名称：

  Synthesis of a representative cis/trans pair of 4,5-disubstituted cyclopentenyllithium reagents

  摘要：

  DOI：

  10.1021/jo00214a008

文献信息

• .pi.-Facially controlled nucleophilic additions of chiral vinylorganometallics to chiral .beta.,.gamma.-unsaturated ketones. 1. Double diastereoselection studies involving 7,7-dimethoxy-5-norbornen-2-one
  作者：Leo A. Paquette、Keith S. Learn

  DOI：10.1021/ja00284a085

  日期：1986.11

  Diastereoselectivite au cours de l'addition de derives du vinyl-cerium avec le dimethylacetal-7,7 de norbornene-5dione-2,7

  Diastereoselectivite au cours de l'addition de Derives duvinyl-cerium avec le dimethylacetal-7,7 de norbornene-5dione-2,7
• Molecular recognition during 1,2-addition of chiral vinyl organometallics to chiral .beta.,.gamma.-unsaturated ketones. Case studies of three 7,7-disubstituted 2-norbornenones. Part 5
  作者：Leo A. Paquette、Keith S. Learn、Jeffrey L. Romine、Ho Shen. Lin

  DOI：10.1021/ja00211a031

  日期：1988.2.3
• Paquette, Leo A.; DeRussy, Donald T.; Vandenheste, Thierry, Journal of the American Chemical Society, 1990, vol. 112, # 14, p. 5562 - 5573
  作者：Paquette, Leo A.、DeRussy, Donald T.、Vandenheste, Thierry、Rogers, Robin D.

  DOI：——

  日期：——
• Model for diastereomer differentiation during 1,2-addition of chrial (racemic) cyclopentenyl organometallics to [4.2.0] bicyclic enones carrying exocyclic .beta.,.gamma.-double bonds
  作者：Leo A. Paquette、Donald T. DeRussy、Judith C. Gallucci

  DOI：10.1021/jo00271a009

  日期：1989.5
• Diastereoselectivities Associated with the 1,2-Addition of Chiral (Racemic) Cyclopentenyl Organometallics to Bicyclo[2.2.2]octenones
  作者：Julien Doyon、Wei He、Leo A. Paquette

  DOI：10.1021/jo00087a017

  日期：1994.4

  The levels of diastereoselection attainable during condensation of the bicyclo[2.2.2]octenones 5-7 with organometallics derived from a selection of the vinyl bromides 8-12 have been determined. The 1,2-additions involving 6 exhibit excellent molecular recognition (>98:2) during syn (endo) addition to the carbonyl group. The diastereoselectivities associated with the capture of 5 and 7 are lower and more variable, although still respectable in several examples. In all cases, the dominant product is the alcohol in which the C-5 substituent on the nucleophilic subunit is beta-oriented. The structural assignments to the numerous alcohols follow from correlations of olefinic carbon chemical shifts, X-ray crystallography in selected examples, and anionic oxy-Cope rearrangement to generate polycyclic ketones whose stereochemical features were defined by NMR methods. The findings provide insight into the transition State geometries adopted in the course of these reactions. The model which has been formulated is consistent with the greater discriminatory power of 6 and conforms closely to earlier proposals for related reactions.