Chemistry of succinyl succinic acid derivatives. Part IV. On the hydrogenation of diethyl succinyl succinate

SummaryThe unique stabilization of the ester link in dialkyl succinyl succinates is explained and a facile route to known as well as lo hitherto inaccessible succinyl succinates is suggested. New representatives of this series are desciribed.Introduction. -Since their early discovery [2]., various syntheses of succinyl succinates, starting from dialkyl succinates [3-161 or from y-halo-acetoacetates [17-251 have been thoroughly described. Transesterification as a straightforward general route has, however, been omitted from the literature, except for two special cases [26] [27], pointing to a possible resistance of the molecule towards such transformation.

show abstract

[1.1]Paracyclophane. Photochemical Generation from the Corresponding Bis(Dewar benzene) Derivative and Theoretical Study of Its Structure and Strain Energy

Tsuji

Ohkita

Konno

et al. 1997

J. Am. Chem. Soc.

View full text Add to dashboard Cite

The first generation of [1.1]paracyclophane (1a) and its bis(methoxycarbonyl) derivative (1b) from the corresponding bis(Dewar benzene) precursors, 3a and 3b, has been investigated. Irradiation of 3a in a glassy mixture of ether-isopentane-ethanol at 77 K leads to the formation of species exhibiting absorption extending to 450 nm, which readily undergoes secondary photolysis to give an isomer showing λ max at 244 nm. On the basis of these UV/vis spectral observations and the accompanying 1 H NMR measurement, the structures of 1a and the corresponding transannular [4 + 4] adduct (21a) are assigned to the initial and the secondary products, respectively. Compound 3b undergoes similar successive phototransformation into 1b and 21b. [1.1]Paracyclophanes, 1a and 1b, and their photoisomers, 21a and 21b, are sufficiently stable to permit the measurement of 1 H NMR spectra at low temperature, but are consumed fairly rapidly in solution at ambient temperature, defying their isolation. The results of geometrical optimization of 1a undertaken at the RHF-SCF, MP2, and B3LYP levels employing the 6-31G* basis set are also presented. Calculations indicate that 1a is a highly strained molecule, but more stable than the related isomers, 3a and 21a: the strain energy calculated for 1a is 128.1, 106.5, and 93.6 kcal/mol at the RHF/6-31G*, B3LYP/6-31G*, and MP2/6-31G* levels, respectively. The closest nonbonding interatomic distance between the aromatic rings in 1a is in a range of 2.36-2.40 Å, and the degree of bending of the benzene rings is comparable to that in [5]paracyclophane, much less as compared to that in [4]paracyclophane. Calculations also support strong transannular electronic interactions between the π-bonds of the aromatic moieties of 1a, which lead to a significantly diminished HOMO-LUMO gap as compared to that in p-xylene. The preparation of 3a and 3b from diethyl 3,6dihydroterephthalate in 15 and 11 steps, respectively, is described.

show abstract

scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.

Contact Info

hi@scite.ai

10624 S. Eastern Ave., Ste. A-614

Henderson, NV 89052, USA

Blog Terms and Conditions API Terms Privacy Policy Contact Cookie Preferences Do Not Sell or Share My Personal Information

Made with 💙 for researchers

Part of the Research Solutions Family.

Chemistry of succinyl succinic acid derivatives. Part IV. On the hydrogenation of diethyl succinyl succinate

Abstract: SummaryThe preparation of 2 new tetrasubstituted cyclohexane isomers by hydrogenation of diethyl succinyl succinate is reported. A route for their formation is postulated.

Cited by 3 publications

References 11 publications

ChemInform Abstract: CHEMISTRY OF SUCCINYL SUCCINIC ACID DERIVATIVES. PART IV. ON THE HYDROGENATION OF DIETHYL SUCCINYL SUCCINATE

ChemInform Abstract: CHEMISTRY OF SUCCINYL SUCCINIC ACID DERIVATIVES. PART IV. ON THE HYDROGENATION OF DIETHYL SUCCINYL SUCCINATE

Chemistry of Succinyl Succinic Acid Derivatives. Part V. On the transesterification of succinyl succinates

[1.1]Paracyclophane. Photochemical Generation from the Corresponding Bis(Dewar benzene) Derivative and Theoretical Study of Its Structure and Strain Energy

Contact Info

Product

Resources

About