(15R,16R,17E,19S)-16-bromo-17-(bromomethylidene)-15-ethyl-1,11-diazapentacyclo[9.6.2.02,7.08,18.015,19]nonadeca-2,4,6,8(18)-tetraene | 186887-60-5

• 分子结构分类: 有机化合物 - 生物碱及其衍生物 - Eburnan型生物碱
• 英文名称: (15R,16R,17E,19S)-16-bromo-17-(bromomethylidene)-15-ethyl-1,11-diazapentacyclo[9.6.2.02,7.08,18.015,19]nonadeca-2,4,6,8(18)-tetraene
• CAS: 186887-60-5
• 化学式: C₂₀H₂₂Br₂N₂
• 分子量: 450.216
• InChiKey: JBMUMCBPBVVJCH-OPUBGNPXSA-N

计算性质

• 辛醇/水分配系数(LogP)：
  4.7
• 重原子数：
  24
• 可旋转键数：
  1
• 环数：
  5.0
• sp3杂化的碳原子比例：
  0.5
• 拓扑面积：
  8.2
• 氢给体数：
  0
• 氢受体数：
  1

反应信息

• 作为反应物：
  描述：

  (15R,16R,17E,19S)-16-bromo-17-(bromomethylidene)-15-ethyl-1,11-diazapentacyclo[9.6.2.02,7.08,18.015,19]nonadeca-2,4,6,8(18)-tetraene 在 sodium tetrahydroborate 、 silver tetrafluoroborate 、 三乙胺 作用下， 以 甲醇 、 二甲基亚砜 为溶剂， 反应 9.5h， 生成 eburnamenine-14-ylmethanol
  参考文献：
  名称：

  Asymmetric Total Synthesis of (+)-Apovincamine and a Formal Synthesis of (+)-Vincamine. Demonstration of a Practical “Asymmetric Linkage” between Aromatic Carboxylic Acids and Chiral Acyclic Substrates

  摘要：

  Asymmetric syntheses of (+)-apovincamine (1a) and (+)-vincamine (2) are described. Construction of the pentacyclic diene lactam 14, a pivotal intermediate for synthesis of the cis-fused vincane-type alkaloids, began by Birch reduction-alkylation of the chiral benzamide 3 to give the 6-ethyl-1-methoxy-4-methyl-1,4-cyclohexadiene 4. Conversion of 4 to 2,5-cyclohexadienone 5 (92% overall yield from 3) and HPLC analysis of 5 demonstrated the diastereomeric purity resulting from the Birch reduction-alkylation to be >100:1. Dienone 5 was converted to butyrolactone 9 (47% overall yield from 3), and 9 was coupled with tryptamine (10) to give the amide 11a. Amido keto aldehyde 13 was obtained from 11a, and acid-catalyzed tricyclization and subsequent base-induced elimination of MeOH provided the desired cis-fused pentacyclic diene lactam 14. Examination of the two-step process 13 --> 14 revealed a novel base-induced epimerization at C(21) which served to interconvert 14 and 17, possibly by the involvement of a homoenolate. Diene lactam 14 was converted to (+)-apovincaminal 20a, an intermediate in the synthesis of (+)-apovincamine (1a) reported by Winterfeldt and co-workers. A new procedure for conversion of 20a to 1a involves conversion of 20a to the acetal 20b and treatment of 20b with NBS/AIBN in CCl4. The conversion of 1a to vincamine (2) has been reported by Oppolzer and co-workers.

  DOI：

  10.1021/jo961603p
• 作为产物：
  描述：

  (14S,15S,19S)-15-ethyl-14-methoxy-17-methyl-1,11-diazapentacyclo[9.6.2.02,7.08,18.015,19]nonadeca-2,4,6,8(18),16-pentaen-12-one 在 lithium aluminium tetrahydride 、 potassium tert-butylate 、 N-溴代乙酰胺 作用下， 以 四氢呋喃 、 乙醚 、 叔丁醇 为溶剂， 反应 49.75h， 生成 (15R,16R,17E,19S)-16-bromo-17-(bromomethylidene)-15-ethyl-1,11-diazapentacyclo[9.6.2.02,7.08,18.015,19]nonadeca-2,4,6,8(18)-tetraene
  参考文献：
  名称：

  Asymmetric Total Synthesis of (+)-Apovincamine and a Formal Synthesis of (+)-Vincamine. Demonstration of a Practical “Asymmetric Linkage” between Aromatic Carboxylic Acids and Chiral Acyclic Substrates

  摘要：

  Asymmetric syntheses of (+)-apovincamine (1a) and (+)-vincamine (2) are described. Construction of the pentacyclic diene lactam 14, a pivotal intermediate for synthesis of the cis-fused vincane-type alkaloids, began by Birch reduction-alkylation of the chiral benzamide 3 to give the 6-ethyl-1-methoxy-4-methyl-1,4-cyclohexadiene 4. Conversion of 4 to 2,5-cyclohexadienone 5 (92% overall yield from 3) and HPLC analysis of 5 demonstrated the diastereomeric purity resulting from the Birch reduction-alkylation to be >100:1. Dienone 5 was converted to butyrolactone 9 (47% overall yield from 3), and 9 was coupled with tryptamine (10) to give the amide 11a. Amido keto aldehyde 13 was obtained from 11a, and acid-catalyzed tricyclization and subsequent base-induced elimination of MeOH provided the desired cis-fused pentacyclic diene lactam 14. Examination of the two-step process 13 --> 14 revealed a novel base-induced epimerization at C(21) which served to interconvert 14 and 17, possibly by the involvement of a homoenolate. Diene lactam 14 was converted to (+)-apovincaminal 20a, an intermediate in the synthesis of (+)-apovincamine (1a) reported by Winterfeldt and co-workers. A new procedure for conversion of 20a to 1a involves conversion of 20a to the acetal 20b and treatment of 20b with NBS/AIBN in CCl4. The conversion of 1a to vincamine (2) has been reported by Oppolzer and co-workers.

  DOI：

  10.1021/jo961603p

文献信息

• Asymmetric Total Synthesis of (+)-Apovincamine and a Formal Synthesis of (+)-Vincamine. Demonstration of a Practical “Asymmetric Linkage” between Aromatic Carboxylic Acids and Chiral Acyclic Substrates
  作者：Arthur G. Schultz、William P. Malachowski、You Pan

  DOI：10.1021/jo961603p

  日期：1997.3.1

  Asymmetric syntheses of (+)-apovincamine (1a) and (+)-vincamine (2) are described. Construction of the pentacyclic diene lactam 14, a pivotal intermediate for synthesis of the cis-fused vincane-type alkaloids, began by Birch reduction-alkylation of the chiral benzamide 3 to give the 6-ethyl-1-methoxy-4-methyl-1,4-cyclohexadiene 4. Conversion of 4 to 2,5-cyclohexadienone 5 (92% overall yield from 3) and HPLC analysis of 5 demonstrated the diastereomeric purity resulting from the Birch reduction-alkylation to be >100:1. Dienone 5 was converted to butyrolactone 9 (47% overall yield from 3), and 9 was coupled with tryptamine (10) to give the amide 11a. Amido keto aldehyde 13 was obtained from 11a, and acid-catalyzed tricyclization and subsequent base-induced elimination of MeOH provided the desired cis-fused pentacyclic diene lactam 14. Examination of the two-step process 13 --> 14 revealed a novel base-induced epimerization at C(21) which served to interconvert 14 and 17, possibly by the involvement of a homoenolate. Diene lactam 14 was converted to (+)-apovincaminal 20a, an intermediate in the synthesis of (+)-apovincamine (1a) reported by Winterfeldt and co-workers. A new procedure for conversion of 20a to 1a involves conversion of 20a to the acetal 20b and treatment of 20b with NBS/AIBN in CCl4. The conversion of 1a to vincamine (2) has been reported by Oppolzer and co-workers.