- Pigments of fungi. LXIII Synthesis of (1S,3R)- and (1R,3S)-austrocortilutein and the enantiomeric purity of austrocortilutein in some Australian Dermocybe toadstools
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The naturally occurring tetrahydroanthraquinones (1S,3R)- and (1R,3S)-austrocortilutein (1b) and (1d), respectively, are synthesized for the first time in enantiomerically pure form by Diels-Alder cycloaddition between the functionalized butadiene derivative (4) and the corresponding monochiral trans-1,3-dihydroxy-1,2,3,4-tetrahydro-5,8-naphthoquinone (5a) or (5b), themselves derived from citramalic acid. Separation of the four stereoisomeric austrocortiluteins by using h.p.l.c. over a chiral stationary phase reveals that the enantiomeric purity of the (1S,3S)-and (1R,3R)-quinones (1a) and (1c) varies from species to species whereas the (1S,3R)-isomer (1b) is, in the five cases examined, enantiomerically pure. CSIRO 2000.
- Elsworth, Catherine,Gill, Melvyn,Raudies, Evelin,Ten, Abilio
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- Preparation of high purity tetrahydrocarbylammonium tetrahydridoborates
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High purity tetrahydrocarbylammonium tetrahydridoborates are prepared under anhydrous conditions by reacting tetrahydrocarbylammonium salts with at least 8% molar excess of an alkali metal hydroxide in the presence of ethanol to produce the corresponding tetrahydrocarbylammonium hydroxides and alkali metal salts, removing the alkali metal salts and adding an alkali metal borohydride to the solution to produce the corresponding tetrahydrocarbylammonium tetrahydridoborates and alkali metal hydroxides.
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