作者:Gerhard Bringmann、Frank Pokorny、Matthias Wenzel、Kathi Wurm、Christoph Schneider
DOI:10.1002/(sici)1099-1344(199701)39:1<29::aid-jlcr936>3.0.co;2-y
日期:1997.1
The isotope labelled monocyclic ketones 5 and 8, postulated precursors to the presumably acetogenic naphthylisoquinoline alkaloids, have been synthesized for biogenetic experiments to Ancistrocladaceae and Dioncophyllacene plants. Key step of the preparation of 1-(2'-[carbonyl-C-14]acetyl-3',5'-dibenzyloxyphenyl)-2-propanone ([C-14]-13) is the C-acetylation of the arylpropanone 10 with the mixed pivalic acetic anhydride ([C-14]-11). The resulting pyrylium salt [C-14]-13, which is stable and can be stored, is cleaved directly before the feeding experiment to give the diketone [C-14]-13 and deprotected to give the free phenolic target molecule [C-14]-5. This synthetic route is applicable also to the prepation of 1-(2'-[C-13(2)]acetyl-3'-hydroxyphenyl)-2-propanone ([C-13(2)]-5) for biosynthetic experiments with NMR analysis. For the preparation of the oxygen-poorer C-13-labelled diketone I-(2'-[methyl-C-13]acetyl-3'-hydroxyphenyl)-2-propanone ([C-13]-8), an 'indanone-route' has been elaborated.