Fixation of the aromatic double bonds in the coumarin ring system

1938 ◽  
Vol 7 (1) ◽  
pp. 8-12 ◽  
Author(s):  
S. Rangaswami ◽  
T. R. Seshadri
Keyword(s):  
Ring System ◽  
Double Bonds ◽  
Coumarin Ring

2,4-Diphenyl-2-(trimethylsilyloxy)-3-dihydro-2H,5H-pyrano[3,2-c][1]benzopyran-5-one

2006 ◽  
Vol 62 (4) ◽  
pp. o1397-o1398
Author(s):  
Yun Liu ◽  
Yong-Miao Shen ◽  
Zhe Li ◽  
Jian-Hua Xu
Keyword(s):  
Title Compound ◽  
Chair Conformation ◽  
Ring System ◽  
Pyran Ring ◽  
Compound C ◽  
Coumarin Ring

In the title compound, C27H26O4Si, the coumarin ring system is essentially planar and the pyran ring adopts a half-chair conformation.

scholarly journals 6-Methyl-4-{[4-(trimethylsilyl)-1H-1,2,3-triazol-1-yl]methyl}-2H-chromen-2-one

IUCrData ◽  
2020 ◽  
Vol 5 (4) ◽  
Author(s):  
Sowmiya Carmel Y. ◽  
N. L. Prasad ◽  
Noor Shahina Begum ◽  
Hari Prasad Suresh
Keyword(s):  
Dihedral Angle ◽  
Title Compound ◽  
Triazole Ring ◽  
Ring System ◽  
Compound C ◽  
Coumarin Ring

In the title compound, C16H19N3O2Si, the dihedral angle between the coumarin ring system (r.m.s. deviation = 0.031 Å) and the triazole ring is 73.81 (8)°. In the crystal, molecules are linked into [010] chains by weak C—H...O interactions.

scholarly journals 4-Methyl-2-oxo-2H-chromen-7-yl 4-methylbenzenesulfonate

2012 ◽  
Vol 68 (4) ◽  
pp. o1191-o1191
Author(s):  
Jian-Xin Yang ◽  
Hong-Yan Liu ◽  
Xiang-Hui Wang
Keyword(s):  
Hydrogen Bonding ◽  
Benzene Ring ◽  
Title Compound ◽  
Crystal Packing ◽  
Three Dimensional ◽  
Ring System ◽  
Maximum Deviation ◽  
Compound C ◽  
The Mean ◽  
Coumarin Ring

In the title compound, C17H14O5S, the coumarin ring system is nearly planar, with a maximum deviation of 0.034 (2) Å from the mean plane. The dihedral angle between the benzene ring and the coumarin ring system is 56.11 (6)°. The crystal packing is stabilized by C—H...O hydrogen bonding, which forms a three-dimensional framework.

scholarly journals 7-Hydroxy-4-(hydroxymethyl)coumarin

IUCrData ◽  
2016 ◽  
Vol 1 (4) ◽  
Author(s):  
Jun-Hua Bai ◽  
Jin-Long Dong
Keyword(s):  
Hydrogen Bonds ◽  
Network Structure ◽  
Title Compound ◽  
Three Dimensional ◽  
Ring System ◽  
Compound C ◽  
Dimensional Network ◽  
Coumarin Ring

In the title compound, C10H8O4, the almost planar coumarin ring system (r.m.s. deviation = 0.0216 Å from the plane through all 11 non-H atoms of the system) has hydroxymethyl and hydroxyl substituents at the 4- and 7-positions, respectively. In the crystal, two classical O—H...O hydrogen bonds generate a three-dimensional network structure.

scholarly journals Dimethyl (7-hydroxy-4-methyl-2-oxo-2H-chromen-3-yl)phosphonate

IUCrData ◽  
2017 ◽  
Vol 2 (8) ◽  
Author(s):  
Yunfei Li ◽  
Yongmei Xiao ◽  
Xinchi Zhang ◽  
Liangru Yang ◽  
Jinwei Yuan ◽  
...  
Keyword(s):  
Hydrogen Bonds ◽  
Dihedral Angle ◽  
Title Compound ◽  
Ring System ◽  
Stacking Interactions ◽  
Phosphonate Group ◽  
Compound C ◽  
Π Stacking ◽  
Methoxy Groups ◽  
Coumarin Ring

In the title compound, C12H13O6P, the coumarin ring system is essentially planar [dihedral angle between the rings = 1.32 (16)°] and the methoxy groups and double-bonded O atom of the phosphonate group are disordered over two sets of sites [occupancy ratio 0.537 (2):0.463 (2)]. In the crystal, C—H...O hydrogen bonds involving the disordered phosphonate O atom as acceptor occur, which generate [100] chains. Weak C—H...O and aromatic π–π stacking interactions [minimum centroid–centroid separation = 3.713 (2) Å] are also observed.

scholarly journals 2-Oxo-2H-chromen-7-yl 4-tert-butylbenzoate

2018 ◽  
Vol 74 (4) ◽  
pp. 530-534 ◽  
Author(s):  
Mohammad Ouédraogo ◽  
Akoun Abou ◽  
Abdoulaye Djandé ◽  
Olivier Ouari ◽  
T. Jérémie Zoueu
Keyword(s):  
Title Compound ◽  
Acute Angle ◽  
Ring System ◽  
Supramolecular Interactions ◽  
Stacking Interactions ◽  
Compound C ◽  
Centroid Distance ◽  
Benzene Rings ◽  
Coumarin Ring ◽  
Good Agreement

In the title compound, C20H18O4, the benzoate ring is oriented at an acute angle of 33.10 (12)° with respect to the planar (r.m.s deviation = 0.016 Å) coumarin ring system. An intramolecular C—H...O hydrogen bond closes an S(6) ring motif. In the crystal, C—H...O contacts generate infinite C(6) chains along the b-axis direction. Also present are π–π stacking interactions between neighbouring pyrone and benzene rings [centroid–centroid distance = 3.7034 (18) Å] and C=O...π interactions [O...centroid = 3.760 (3) Å]. The data obtained from quantum chemical calculations performed on the title compound are in good agreement with the observed structure, although the calculated C—O—C—C torsion angle between the coumarin ring system and the benzoate ring (129.1°) is somewhat lower than the observed value [141.3 (3)°]. Hirshfeld surface analysis has been used to confirm and quantify the supramolecular interactions.

Inexpensive multigram-scale synthesis of cyclic enamines and 3-N spirocyclopropyl systems

2018 ◽  
Vol 16 (4) ◽  
pp. 652-656 ◽  
Author(s):  
Pratik Kumar ◽  
Omar Zainul ◽  
Scott T. Laughlin
Keyword(s):  
Ring System ◽  
Protecting Groups ◽  
Double Bonds ◽  
Pharmacological Targets ◽  
System P

Cyclic enamines are important synthons for many synthetic and pharmacological targets. We report a method for the synthesis of cyclic enamines with exocyclic double bonds and four- to seven-membered rings that permits usage of common N-protecting groups and tolerates functionality round the ring system.

Reinvestigation of seselin

2006 ◽  
Vol 62 (4) ◽  
pp. o1340-o1341 ◽  
Author(s):  
A. K. Bauri ◽  
Sabine Foro ◽  
Hans-Jörg Lindner ◽  
Sandip K. Nayak
Keyword(s):  
Crystal Structure ◽  
Hydrogen Bond ◽  
Chair Conformation ◽  
Ring System ◽  
Pyran Ring ◽  
Coumarin Ring

The crystal structure of seselin (2′,2′-dimethyl-3-pyreno[6,5:7,8]coumarin), C14H12O3, a bioactive pyrenocoumarin, has been reinvestigated. The coumarin ring system is nearly planar and the α-pyran ring adopts a distorted half-chair conformation. An intermolecular C—H...O hydrogen bond is observed.

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