Aminobicyclo[n. 1.0]alkane derivatives
Cyclopropanes, nucleophilic substitution at
Springer Online Journal Archives 1860-2000
Chemistry and Pharmacology
Abstract Reaction of morpholinobicycloalkyl-dimedone4 C with various CH-acids3 leads to a substitution of theexo-dimedone unit as a consequence of a strong preference of theexo-leaving group in a bicyclic compound of type4 and5, respectively. Dimedone (3 C) as a nucleophile, however, makes theexo substitution unproductive in4 C and allows the displacement of the morpholino moiety leading to12 C. Thus compounds12 C–12 F could be obtained directly from the N,O-acetal1 and the CH-acids3 C–3 F by a twofold substitution, the isolation of the monoalkylated compounds4 not being necessary. Formation of12 C–12 F involves aMichael addition of3 C–3 F to the unstable 2-Cyclopropylidene-1,3-cycloalkanedione intermediates7 C–7 F. Cyclopentanedione3 F as a CH-acid and1 gave the enamine17 F besides12 F. The Hexahydroazepino-N,O-acetal19 in this special case was superior leading exclusively to12 F.
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