Preparation of adamantyl derivatives of 1,4‐; 1,6‐ and 1,7‐dihydroxynaphthalenes and assignment of their NMR data

Abstract

Adamantylation of dihydroxynaphthalenes with the hydroxyl groups on the same or different rings leads to compounds that are convenient starting materials in target-oriented organic synthesis. Here, we report the (1)H and (13)C NMR assignments of eight 1-adamantyl substituted derivatives of 1,4-; 1,6- and 1,7-dihydroxynaphthalenes. The data acquired and peculiarities of their molecular structure are useful for extrapolation for prompt characterization of compounds containing adamantane, dihydroxynaphthalenes or naphthoquinone units.

Spectral assignment of new adamantane derivatives of 1,3‐; 1,5‐dihydroxy‐ and 1,5‐dimethylnaphthalenes

“…Final confirmation of connection of adamantane to C‐4 carbon is made based on the fact that H‐4 proton in HMBC spectrum has cross‐peak with only one carbonyl group at C‐3 as opposed to H‐2 protons (two cross‐peaks with C‐3 and C‐1 carbons). In adamantyl part of spectrum we observed characteristic features which have been described in details in our previous work …”

“…In adamantyl part of 1 H and 13 C spectra there is a frequency shifting from H β and C β nuclei in case of compound 3 . As we mentioned earlier such shifting appears due to deshielding effect of the hydroxyl group. This pattern in NMR spectra can be further evidence in confirming the structure of various polyphenolic compounds with an attached adamantane fragment in the ortho ‐position.…”

“…We describe here assignments of 1 H and 13 C NMR spectra of synthesized 1‐adamantyl substituted compounds I‐III . Additionally, previously defined patterns on the effect of OH‐group in the ortho ‐ or meta ‐ position to adamantane for its 1 H and 13 C NMR spectra have been confirmed on the basis of found spectral data.…”

“…Current report is an ongoing research of determination structure and features of adamantyl derivatives of dihydroxynaphthalenes by NMR spectroscopy . We describe here assignments of 1 H and 13 C NMR spectra of synthesized 1‐adamantyl substituted compounds I‐III .…”

1 H and 13 C NMR spectral assignments of novel adamantyl and di-adamantyl derivatives of 1,2-dihydroxynaphthalenes, 1,8-dihydroxynaphthalenes, 2,3-dihydroxynaphthalenes, 2,6-dihydroxynaphthalenes and 2,7-dihydroxynaphthalenes

“…We continue to describe adamantyl derivatives of the homologous series of different naphthalenediols and their NMR features. Previously, NMR spectra of 1,4‐dihydroxynaphthalenes, 1,6‐dihydroxynaphthalenes, 1,7‐dihydroxynaphthalenes, 1,3‐dihydroxynaphthalenes and 1,5‐dihydroxynaphthalenes with one or two adamantyl groups were characterized in details . In the current paper, we report complete 1 H and 13 C spectral assignments of mono‐adamantyl and di‐adamantyl‐containing derivatives of 1,2‐dihydroxynaphthalenes, 2,3‐dihydroxynaphthalenes, 2,6‐dihydroxynaphthalenes, 2,7‐dihydroxynaphthalenes and 1,8‐dihydroxynaphthalenes and 6‐(1‐adamantyl)‐2,3‐dihydroxynaphthalene synthesized previously .…”