STEREOCHEMISTRY OF 4-AMINO-(D-3)-TRISHOMOCUBANES - NMR-STUDY OF 3-PHENYL-4-AMINO-(D-3)-TRISHOMOCUBANE

Amino compounds of the highly symmetrical (D-3)-trishomocubane were recently shown to possess promising biological activities, i.e. antivirial and antiparkinson. This series was synthesized via a modified Ritter reaction. The unique hydrocarbon skeleton of these compounds has a D-3 point group symmetry with a propeller shape. Several geometrical isomers are possible for the derivatives of (D-3)-trishomocubane, This paper reports the complete H-1 and C-13 NMR assignments and the configuration at C-4 of one of the most promising compounds of the present series, i.e. 3-phenyl-damino-(D-3)-trishomocubane. The C-13 NMR spectrum of this amine indicates the presence of only one geometrical isomer for the compound. NOE experiments on the fully assigned H-1 NMR spectrum show that this isomer has the 3S4S/3R4R configuration, and not the 3S4R/3R4S configuration. These results indicate that the Ritter rearrangement proceeds stereospecifically and that it provides a facile method for the synthesis of (D-3)-trishomocuban-4-amines from tertiary alcohols of pentacyclo[5.4.0.0(2,6).0(3,10).0(5,9)]undecan-8-ol.