Synthesis, X-Ray And Complete Assignments Of H-1 And C-13 Nuclear Magnetic Resonance Data For Novel Dichloro-1,4-Dihydro-1,4-Epoxynaphtalene Derivatives

Benzyne from trichlorobenzene has been employed for Diels-Alder cycloaddition with dienes, such as furan and 2,5-dimethylfuran, to synthesized novel dichloro-1,4-dihydro-1,4-epoxynaphtalene derivatives. These compounds have not been characterized or reported. The H-1 NMR spectra of cycloadducts were fine resolved, and unambiguous proton chemical shift assignments were based on the multiplicity pattern of proton resonance and confirmed by 2D NMR from COSY, HSQC, and HMBC data. Computational calculations were performed for a crystal of 5,6-dichloro-1,4-dihydro-1,4-epoxynaphtalene. This compound crystallized as a monoclinic system in the space group C2/c with eight molecules in the unit cell, a = 18.313 (6) angstrom, b = 8.128 (3) angstrom, c = 14.157 (4) angstrom, beta= 119.942 (9)degrees, V = 1825.9 (10) angstrom(3), Z = 8. (C) 2020 Elsevier B.V. All rights reserved.