The Conformations of Substituted Cyclopentanes. I. The Infrared Analysis and Structure of the α-Halocamphors, the α-Halo-2-indanones and the α-Halocyclopentanones

Brutcher, Frederick V.; Roberts, Theodore; Barr, Samuel J.; Pearson, N.

doi:10.1021/ja01527a039

Cited by 87 publications

(12 citation statements)

References 1 publication

Supporting

Mentioning

Contrasting

Order By: Relevance

“…This ring has an envelope conformation with an angle of 27"5 ° between the planes corresponding to C(7), C(8), C(9) and to C(4), C(5), C(7), C(9). The atom C(8) is 0-49 A from the plane formed by C(4), C(5), C(7), C(9), in agreement with the theoretical calculations for minimum energy (Pitzer & Donath, 1959;Brutcher, Roberts, Barr & Pearson, 1959) and other crystal structure determinations (Allen, Rogers & Troughton, 1971). C(4),C(7),C(8),C(9) 0.08 C(7),C(8),C(9),C(5) 0.07 C(8),C(9),C(5),C(4) 0-02 C(9),C(5),C(4),C (7) 0.00 C(5),C(4),C(7),C(8) 0-03…”

Section: The Molecular Structuresupporting

confidence: 86%

The crystal structure of monobromodehydrobispulegone

Franco¹,

Martínez-Carrera²,

García-Blanco³

1974

Acta Crystallogr Sect B

View full text Add to dashboard Cite

Crystals of monobromodehydrobispulegone, C20H27BrO, are orthorhombic, space group P2~2121, with four molecules per unit cell. The lattice constants are: a = 11.656 (2), b = 11.669 (2), c = 12.766 (2)/~. The crystal structure has been solved by the heavy-atom technique and refined by the full-matrix least-squares method. The final R index for 692 independent observed reflexions is 0.107. The molecule shows stress in the pentagonal ring. In the cyclohexane ring the oxygen and bromine substituents appear to be coplanar and the methyl substituent is in an axial position. The molecular packing shows no remarkable directional features.

show abstract

Section: The Molecular Structuresupporting

confidence: 86%

The crystal structure of monobromodehydrobispulegone

Franco¹,

Martínez-Carrera²,

García-Blanco³

1974

Acta Crystallogr Sect B

View full text Add to dashboard Cite

show abstract

“…A rho value of -0.66 measured for the pyrolysis of the 1-arylethylacetates at 327° (following o-"*" relationship) (85) and a rate acceleration by electronegatlvely substituted aryl esters (86) indicates a small degree of charge separation on the alpha-carbon. This Is in agreement with the \ / (9) \ R relative pyrolytic rates (3° > 2° > 1°) of substituted esters (83).…”

Section: H-c-c+supporting

confidence: 88%

Syntheses and eliminations of cyclopentyl derivatives

Rausch

View full text Add to dashboard Cite

“…The [1,2,2]-bic~~clohe~tane system call be considered as two fused five-membered rings. Each ring is approximateljin the C, (15) or envelope (16) conformation. The assumption of complete (or almost complete) eclipsing of carbons 2 and 3 is probably a good one in this case, as any staggering increases the consiclerable strain already present.…”

mentioning

confidence: 99%

Coupling Constants in Rigid Five-Membered Rings: N.M.R. Spectra of the Camphane-2,3-Diols

Anet¹

1961

Can. J. Chem.

129

View full text Add to dashboard Cite

A B S T R A C T T h e proton ~~u c l e a r magnetic resonance (N.M.R.) spectra o f the four diastereoisomers o f camphane-2,3-diol are reported. T h e coupling constants between the 2-, 3-, and 4-protons agree with t h e values predicted byICarplus for ethane derivatives. In particular, the cis (0" dihedral angle) coupling constants (7.7 and 8.9 c.p.s.) INTRODUCTIONIndirect spin-spin coupli~lg constants in substituted ethane clerivatives have attracted attention because of the depeizcleilce of their values on the dihedral angle between the CH bonds involved (1-7). The dilzedl-a1 angles are 60" and 180" in non-cyclic substiti~tecl ethanes, ~vhich, in general, exist in staggered rather than eclipsed forms. Tlzese are also the dihedral angles between vicinal C H bonds in six-membered rings existing in chair conforinations. I n each case the observed coupling constants may be weighted averages if more than one conformation exists to a n appreciable extent.Karplus (8) '~lfaaltz~script received iVovenrber 28, 1960.

show abstract

The Conformations of Substituted Cyclopentanes. I. The Infrared Analysis and Structure of the α-Halocamphors, the α-Halo-2-indanones and the α-Halocyclopentanones

Cited by 87 publications

References 1 publication

The crystal structure of monobromodehydrobispulegone

The crystal structure of monobromodehydrobispulegone

Syntheses and eliminations of cyclopentyl derivatives

Coupling Constants in Rigid Five-Membered Rings: N.M.R. Spectra of the Camphane-2,3-Diols

Contact Info

Product

Resources

About