Crystal structure of 4-acetyl[2.2]paracyclophane, C<sub>18</sub>H<sub>18</sub>O

Jones, Peter G.; Bubenitschek, Peter; Hopf, Henning; Pechlivanidis, Z.

doi:10.1524/zkri.1993.208.part-1.136

Cited by 8 publications

(2 citation statements)

References 0 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…In principle the alternative orientation is also possible, with the methyl substituent taking this position. A comparable situation has been observed for the 4-acetyl derivative of [2.2]paracyclophane, with the difference that the preferred endo -conformation has been observed both for the solid state [ 8 – 10 ] and in solution by NMR spectroscopy [ 11 ].…”

Section: Resultssupporting

confidence: 60%

Five-membered ring annelation in [2.2]paracyclophanes by aldol condensation

Hopf¹,

Narayanan²,

Jones³

2014

Beilstein J. Org. Chem.

View full text Add to dashboard Cite

SummaryUnder basic conditions 4,5,12,13-tetraacetyl[2.2]paracyclophane (9) cyclizes by a double aldol condensation to provide the two aldols 12 and 15 in a 3:7 ratio. The structures of these compounds were obtained from X-ray structural analysis, spectroscopic data, and mechanistic considerations. On acid treatment 12 is dehydrated to a mixture of the condensed five-membered [2.2]paracyclophane derivatives 18–20, whereas 15 yields a mixture of the isomeric cyclopentadienones 21–23. The structures of these elimination products are also deduced from X-ray and spectroscopic data. The sequence presented here constitutes the simplest route so far to cyclophanes carrying an annelated five-membered ring.

show abstract

Section: Resultssupporting

confidence: 60%

Five-membered ring annelation in [2.2]paracyclophanes by aldol condensation

Hopf¹,

Narayanan²,

Jones³

2014

Beilstein J. Org. Chem.

View full text Add to dashboard Cite

show abstract

“…If this ring was positioned in endo orientation (pointing towards the unaffected benzene ring), one of its carbonyl groups would be close to one of the bridge protons, causing a shift to lower field. This effect has been observed for several derivatives of [2.2]paracyclophane carrying a carbonyl‐containing substituent in the 4‐position 17. In all these cases the methylene proton facing the carbonyl function is shifted to approximately δ = 4.0 ppm, whereas all other bridge protons absorb below δ = 3.8 ppm.…”

Section: Preparation Of the 4‐alkenyl[22]paracyclophanesmentioning

confidence: 74%

Cycloadditions to Alkenyl[2.2]paracyclophanes

et al. 2006

View full text Add to dashboard Cite

Cycloadditions between the 4-alkenyl[2.2]paracyclophanes 7, 16-21 and the dienophiles 10a-h have been studied. Whereas 10a, b, d, and g prefer Diels-Alder addition involving the olefinic double bond and one double bond of a cyclophane benzene ring, 10c, e, f, and h undergo other cycloadditions such as ene reaction (10c), [2+2] cycloaddition to the olefinic double bond (10e) and heterodiene addition to

show abstract

Novel Multichiral Diols and Diamines by Highly Stereoselective Pinacol Coupling of Planar Chiral [2.2]Paracyclophane Derivatives

Сергеева

Rozenberg

Antonov

et al. 2005

Chemistry A European J

View full text Add to dashboard Cite

The TiCl4/Zn-mediated intermolecular pinacol coupling of the planar chiral carbonyl compounds [2.2]paracyclophane-4-carbaldehyde, 4-acetyl[2.2]paracyclophane (ketone) and the four regioisomeric 5-, 7-, 12- and 13-methoxy[2.2]paracyclophane-4-carbaldehydes as well as the pTosOH-Zn/Cu-promoted coupling of their N-substituted imines is described. Coupling of the enantiomerically pure substrates (most of carbonyl compounds and all imines) occurs stereoselectively giving rise to diastereomerically pure 1,2-diols and 1,2-diamines. Racemic aldehydes and ketone react with different degrees of stereoselectivity (depending on the substituents in certain positions) and produce one to three diastereomers. 7-methoxy[2.2]paracyclophane-4-carbaldehyde undergoes a tandem pinacol coupling-pinacol rearrangement to yield bis-(7-methoxy[2.2]paracyclophane-4-yl)acetaldehyde. Coupling of the racemic imines produces a mixture of single racemic D,L-diamine and single meso-diamine in each case. The stereoselective formation of the asymmetric centres is governed by the planar chiral [2.2]paracyclophanyl moiety. The techniques elaborated are extended to the intramolecular coupling of [2.2]paracyclophane-4,13-dicarbaldehyde and its bis-N-phenylimine, resulting in stereoselective formation of the chiral triply-bridged diol and exclusive formation of the meso-diamine. X-Ray investigations of several diols and diamines have been carried out and the structural features of these derivatives are discussed.

show abstract

Crystal structure of 4-acetyl[2.2]paracyclophane, C₁₈H₁₈O

Cited by 8 publications

References 0 publications

Five-membered ring annelation in [2.2]paracyclophanes by aldol condensation

Five-membered ring annelation in [2.2]paracyclophanes by aldol condensation

Cycloadditions to Alkenyl[2.2]paracyclophanes

Novel Multichiral Diols and Diamines by Highly Stereoselective Pinacol Coupling of Planar Chiral [2.2]Paracyclophane Derivatives

Contact Info

Product

Resources

About

Crystal structure of 4-acetyl[2.2]paracyclophane, C18H18O

Cited by 8 publications

References 0 publications

Five-membered ring annelation in [2.2]paracyclophanes by aldol condensation

Five-membered ring annelation in [2.2]paracyclophanes by aldol condensation

Cycloadditions to Alkenyl[2.2]paracyclophanes

Novel Multichiral Diols and Diamines by Highly Stereoselective Pinacol Coupling of Planar Chiral [2.2]Paracyclophane Derivatives

Contact Info

Product

Resources

About

Crystal structure of 4-acetyl[2.2]paracyclophane, C₁₈H₁₈O