Protonation of conjugated carbonyl groups in sulfuric acid solutions. II. Protonation and basicity of α,β-unsaturated alicyclic ketones

Abstract

The protonation of 14 a$-unsaturated alicyclic ketones, B, by sulfuric acid leads to values of log [B]/[BHC] which, when plotted against the amide acidity function, HA, give straight lines of unit slope. The pKBH+ values thus obtained show substituent effects which are additive and can be interpreted in terms of polar and resonance effects.

Protonation of conjugated carbonyl groups in sulfuric acid solutions. III. α,β-Unsaturated ketosteroids

“…They are commercial materials, except for conlpounds 18 and 19, which were synthesized from 1 and testosterone propionate, respectively, by dehydrogenation with chloranil in t-butyl alcohol (3). Compounds 18 and 19 melted a t 168.5-169" and 135-136", respectively, and their ultraviolet spectra in ethanol agreed with literature data (4,5 The method and apparatus used to determine pKDII+ have been described previously (1). However, in the present work an additional complication is present.…”

“…All the recovered substances show the FIG. 1 characteristic absorption bands of a,P-unsaturated ketones in the ultraviolet and infrared. Infrared spectra of substances recovered from sulfuric acid solutions of 17B-hydroxy-and 17-keto-compounds showed the loss of these groups, but the Aa-3-one system was evidently not destroyed.…”

Chromophoraktivierung von α,β‐ungesättigten Carbonylverbindungen und ihre Anwendung in enantioselektiven Photoreaktionen

“…[42] WiefürCrotonaldehyd (38)fanden sie auch füra lle anderen untersuchten Verbindungen eine Verschiebung der pp*-Absorption zu hçheren Wellenlängen (Schema 20), wobei wie für 39 der Absorptionskoeffizient in der Regel zunahm. [42] WiefürCrotonaldehyd (38)fanden sie auch füra lle anderen untersuchten Verbindungen eine Verschiebung der pp*-Absorption zu hçheren Wellenlängen (Schema 20), wobei wie für 39 der Absorptionskoeffizient in der Regel zunahm.…”

Protonation acidity constants for benzotoluidides in sulfuric acid solutions

“…Values of log {c H+ } and X are available for aqueous H 2 SO 4 [21]. The data for H 0 and H A are calculated using equations: -H 0 = X + log{c H+ } [22] and H A = 0.53 H 0 + 0.68 [23], respectively. Ionization ratios are calculated using the following equation:…”