ISSN:
0018-019X
Schlagwort(e):
Chemistry
;
Organic Chemistry
Quelle:
Wiley InterScience Backfile Collection 1832-2000
Thema:
Chemie und Pharmazie
Notizen:
Syntheses of Moniliformin, a Mycotoxine with a Cyclobutenedione StructureSix different routes to 3-hydroxy-3-cyclobutene-1, 2-dione (4), the free acid of the mycotoxine Moniliformin (=alkali salt of 4) are described. A common feature of all pathways is the synthesis of cyclobutanes having the oxidation level 6. Moniliformin precursors which are easily transformed to 4 by acid catalysed hydrolysis include [2+2]-cycloadducts of ketene with tetraalkoxy-olefins, 3,4,4-trialkoxycyclobutenes, derivatives of polyfluorinated cyclobutenes, the brominated [2+2]-cycloadduct of ethyl vinyl ether and dichloroketene, tetrabromocyclobutanone, [2+2]-photocycloadducts of dichlorovinylenecarbonate with dichloroethylenes, and the dimer of chloroketene. The most convenient synthesis via the [2+2]-cycloadduct of tetraethoxyethylene and ketene (14b) is reported in detail and produces 4 in four simple steps in 57% overall yield. In addition, two new syntheses of squaric acid (56) are described.
Zusätzliches Material:
3 Tab.
Materialart:
Digitale Medien
URL:
http://dx.doi.org/10.1002/hlca.19780610526
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