3,4-dihydro-5-hydroxy-2,7-dimethyl-8-(3''-methyl-2''-butenyl)-2-(4'-methyl-1',3'-pentadienyl)-2H-1-benzopyrane-6-carboxylic acid | 1188548-54-0

• 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: 3,4-dihydro-5-hydroxy-2,7-dimethyl-8-(3''-methyl-2''-butenyl)-2-(4'-methyl-1',3'-pentadienyl)-2H-1-benzopyrane-6-carboxylic acid
• 英文别名: (2R)-5-hydroxy-2,7-dimethyl-8-(3-methylbut-2-enyl)-2-[(1E)-4-methylpenta-1,3-dienyl]-3,4-dihydrochromene-6-carboxylic acid
• CAS: 1188548-54-0
• 化学式: C₂₃H₃₀O₄
• 分子量: 370.489
• InChiKey: LJFBYGPHKHZLQD-LZMFZKJZSA-N

计算性质

• 辛醇/水分配系数(LogP)：
  6.7
• 重原子数：
  27
• 可旋转键数：
  5
• 环数：
  2.0
• sp3杂化的碳原子比例：
  0.43
• 拓扑面积：
  66.8
• 氢给体数：
  2
• 氢受体数：
  4

反应信息

• 作为产物：
  描述：

  3,4-dihydro-5-hydroxy-2,7-dimethyl-8-(3-methyl-2-butenyl)-2-(4-methyl-1,3-pentadienyl)-2H-1-benzopyran-6-carboxylic acid 在 Daicel Chiralcel OD-H chiral column 作用下， 生成 3,4-dihydro-5-hydroxy-2,7-dimethyl-8-(3''-methyl-2''-butenyl)-2-(4'-methyl-1',3'-pentadienyl)-2H-1-benzopyrane-6-carboxylic acid 、 3,4-dihydro-5-hydroxy-2,7-dimethyl-8-(3''-methyl-2''-butenyl)-2-(4'-methyl-1',3'-pentadienyl)-2H-1-benzopyrane-6-carboxylic acid
  参考文献：
  名称：

  Absolute configuration reassignment of two chromanes from Peperomia obtusifolia (Piperaceae) using VCD and DFT calculations

  摘要：

  Previous analysis of the ECD spectra of two prenylated benzopyrans isolated from Peperomia obtusifolia, by means of the helicity rule for the chromane chromophore, resulted in the incorrect assignment of their absolute configuration, (5) instead of (R) for a deduced P-helicity of the chromane ring for the (+)-enantiomers. This was discovered by the application of DFT calculations and VCD spectroscopy. Experimental and calculated (B3LYP/6-31G(d)) VCD and IR spectra were compared, and a definitive absolute configuration of (+)-1 and (+)-2 is reassigned directly in solution as (R). The assumption of equatorial positioning of bulky groups, shown here to be invalid for the title molecules, is the underlying cause of the previous incorrect assignment of absolute configuration. Moreover, TDDFT (B3LYP/6-311++G(2d,2p)//B3LYP/6-31G(d)) calculations of ECD spectra have shown that both P- and M-helicity of the heterocyclic ring, for a given absolute configuration, lead to the same sign for the L-1(b) ECD band, thus bringing into question the validity of the empirical ECD helicity rule for chromane molecules. (C) 2010 Elsevier Ltd. All rights reserved.

  DOI：

  10.1016/j.tetasy.2010.09.004

文献信息

• Absolute configuration reassignment of two chromanes from Peperomia obtusifolia (Piperaceae) using VCD and DFT calculations
  作者：João Marcos Batista、Andrea N.L. Batista、Daniel Rinaldo、Wagner Vilegas、Quezia B. Cass、Vanderlan S. Bolzani、Massuo J. Kato、Silvia N. López、Maysa Furlan、Laurence A. Nafie

  DOI：10.1016/j.tetasy.2010.09.004

  日期：2010.10

  Previous analysis of the ECD spectra of two prenylated benzopyrans isolated from Peperomia obtusifolia, by means of the helicity rule for the chromane chromophore, resulted in the incorrect assignment of their absolute configuration, (5) instead of (R) for a deduced P-helicity of the chromane ring for the (+)-enantiomers. This was discovered by the application of DFT calculations and VCD spectroscopy. Experimental and calculated (B3LYP/6-31G(d)) VCD and IR spectra were compared, and a definitive absolute configuration of (+)-1 and (+)-2 is reassigned directly in solution as (R). The assumption of equatorial positioning of bulky groups, shown here to be invalid for the title molecules, is the underlying cause of the previous incorrect assignment of absolute configuration. Moreover, TDDFT (B3LYP/6-311++G(2d,2p)//B3LYP/6-31G(d)) calculations of ECD spectra have shown that both P- and M-helicity of the heterocyclic ring, for a given absolute configuration, lead to the same sign for the L-1(b) ECD band, thus bringing into question the validity of the empirical ECD helicity rule for chromane molecules. (C) 2010 Elsevier Ltd. All rights reserved.