THE SYNTHESIS OF CONDENSED RING COMPOUNDS. IX. THE REACTION OF 5-ACETOXY-1,4-TOLUQUINONE WITH CONJUGATED DIENES, AND THE RULES OF ALDER¹

THE SYNTHESIS OF CONDENSED RING COMPOUNDS. XIII. THE PREPARATION OF 5- AND 6-CARBALKOXY-1,4-TOLUQUINONES. ADDITION OF 5-CARBOMETHOXY-1,4-TOLUQUINONE AND 6-CARBOMETHOXY-1,4-TOLUQUINONE TO BUTADIENE1

“…Under the experimental conditions usually employed for the addition of toluquinones to dienes, then, 5-carbomethoxy-l ,4-toluquinone reacts almost exclusively at its carbomethoxyethene link with butadiene, and 6-carbomethoxy-1,4-toluquinone reacts at least principally at this link. The selectivity in the formation of structural isomers exhibited by these reactants supports the generalization of Alder and Stein (5) and its extension to the prediction of the chief structural isomers, as recently proposed (6).…”

Stereochemistry of the Diels-Alder Reaction.

“…The properties of the two isolated products were consonant with the structures predicted by this analysis. This method was applied to a number of reported adducts of unknown structure and configuration (110), and in at least one case (265) their predictions have been confirmed experimentally.…”

“…In an attempt to reduce the principle of "maximum overlap of double bonds" to a more quantitative basis, Butz and Butz (110) developed a method of geometrical analysis, which they applied to the reaction of 1,3-cyclohexadiene with 5-acetoxytoluquinone. Employing accurate scale drawings of the diene superimposed on the dienophile in four possible prereaction orientations, they measured the distances between all combinations of the centers of all the double bonds present, assuming an interplanar separation of 1.39 A.…”

Activated Carbon-Promoted Dehydrogenation of Hydroquinones to Benzoquinones, Naphthoquinones, and Anthraquinones under Molecular Oxygen Atmosphere

“…Yield 90% (216 mg, 1.1 mmol), yellow solid, mp 107.1–107.5 °C (lit . mp 107.5–108.5 °C); IR (neat) 586, 649, 680, 699, 733, 805, 876, 919, 985, 1021, 1067, 1209, 1276, 1298, 1319, 1340, 1381, 1450, 1595, 1623, 1664, 2917, 2945, 3053; 1 H NMR (400 MHz, CDCl 3 ) δ = 7.83 (s, 1H), 7.80 (s, 1H), 6.76 (q, J = 1.5 Hz, 1H), 2.39 (d, J = 2.0 Hz, 6H), 2.17 (d, J = 1.6 Hz, 3H); 13 C­{ 1 H} NMR (100 MHz, CDCl 3 ) δ = 185.5, 185.1, 147.7, 143.2, 143.2, 135.3, 130.0, 129.9, 127.3, 126.9, 20.0, 20.0, 16.3.…”