A stable enol from a 6-substituted benzanthrone and its unexpected behaviour under acidic conditions

Abstract

SummaryTreatment of benzanthrone (1) with biphenyl-2-yl lithium leads to the surprisingly stable enol 4, which is converted by dehydrogenation into the benzanthrone derivative 7. Under acidic conditions 4 isomerises to the spiro compound 11 and the bicyclo[4.3.1]decane derivative 12. Furthermore, the formation of 7 and the hydrogenated compound 13 is observed. A mechanism for the formation of the reaction products is proposed and supported by DFT calculations.

Atom interaction propensities of oxygenated chemical functions in crystal packings

“…A Debeaux et al, 2009) has a unique hydroxyl group which forms an intramolecular O-HÁ Á Á weak hydrogen bond (Levitt & Perutz, 1988) with an aromatic cycle (Fig. S6).…”

Rules of Nucleophilic Additions to Zigzag Nanographene Diones**

“…To confirm this hypothesis, we performed the reaction of A1 with an excess of mesityl magnesium bromide (MesMgBr, Table 1) and isolated exclusively the product of a double 1,4‐addition A11 (91 %) [33] . The same change of selectivity upon increasing steric bulk of the nucleophile was observed for benzophenalenone [34] . The steric argument holds true also for the case of 1,2‐addition of thienyl lithium to anthanthrone, [20a] as thienyl is less bulky than 3,5‐di‐ tert ‐butylphenyl.…”

Tales of the Unexpected: Selectivity of Nucleophilic Additions to Zigzag Nanographene Diones

“…The same change of selectivity upon increasing steric bulk of the nucleophile was observed for benzophenalenone. 29 The steric argument holds true also for the case of 1,2-addition of thienyl lithium to anthanthrone, 19a as thienyl is less bulky than 3,5-di-tert-butylphenyl.…”