J. Wilamowski, W. Krasodomski, B. Nowak
Aug 1, 1995
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0
Influential Citations
1
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Journal
Liebigs Annalen
Abstract
Cyclization of ethyl (E)/(Z)-[2-(1-cyclohexen-1-yl)cyclohexylidene]cyanoacetate (2) in cold concentrated sulfuric acid affords 10-amino-1,2,3,4,5,6,7,8-octahydrophenanthrene-9-carboxylic acid (4) and 3,5,6,7,8,8a-hexahydro-3-oxospiro-[1H-2-benzopyran-1,1′-cyclohexane]-4-carbonitrile (5). The o-amino acid 4 is employed in the synthesis of several 1,2,3,4,5,6,7,8-octahydrophenanthrene derivatives: the carboxylic acid 6, o-hydroxy carboxylic acid 7, and the amine 8. The lactone 5 undergoes decarboxylation on heating yielding a mixture of unsaturated nitriles 9 and 10 which are cyclized to the amine 8.