187. Absorption spectra of some naturally-occurring naphthaquinones and their derivatives

Crystal structure and Hirshfeld surface analysis of lapachol acetate 80 years after its first synthesis

“…Lapachol (2-hydroxy-3-(3-methyl-but-2-enyl)-[1,4]naphthoquinone), isolated from Handroanthus Heptaphyllus (Vell.) Mattos, a native species from Paraguay, was studied as a hemisynthetic precursor of lapachol acetate {[3-(3-methyl-but-2-enyl)-1,4-dioxonaphthalen-2-yl]acetate} for the first time by Cooke et al (1939). Jacobsen & Torsell (1973) prepared lapachol acetate using 2-acetoxy-1,4naphthoquinone as a precursor with 79% yield.…”

“…Jacobsen & Torsell (1973) prepared lapachol acetate using 2-acetoxy-1,4naphthoquinone as a precursor with 79% yield. We developed an optimization of the first synthesis of lapachol acetate developed by Cooke et al (1939), introducing several modifications with the purpose of standardizing it and increasing the yield to 97.5%. Details of the synthesis and the spectroscopic characterization are included in the supporting information.…”

On the Structure of Eremophilone

“…This compound, described as a "phenol," C12H13O3, was formedlb when hydroxyeremophilone, its benzoate and its methyl ether were oxidized, ozone and chromic acid being used in the several experiments performed. 2 The "phenol," which was soluble in alkali but not in sodium bicarbonate solution, formed an acetate and a methyl ether, both of which (2) The term "phenol" was (and is here) used simply with reference to its solubility in alkali and insolubility in sodium bicarbonate solti- Ci2-oxidation product would most probably be derived by the loss of the three carbon atoms of the isopropylidene group, and that it would be represented by III OH Although the oxidation of II in this manner would appear unlikely, the composition of the "phenol"…”