L. Paquette, I. Itoh, W. Farnham
Dec 1, 1975
Citations
0
Influential Citations
18
Citations
Journal
Journal of the American Chemical Society
Abstract
Pinacolic reduction of both optically pure and racemic hexahydrotriquinacen-2-one ( 6 ) proceeds with exo,exo carbon-carbon bond formation. Coupling of enantiomerically pure 6 produces diol 11 exclusively. Formation of comparable amounts of 11 and 12 from ( f ) 6 shows that the diastereomeric transition states involved are of comparable energy. Studies with chiral and racemic 2,3-dihydrotriquinacen-2-one (13) gave analogous results. The various 1,2-glycols are identified by their I3C N M R (symmetry is thereby revealed), ‘H NMR (shielding of the endo protons at Cj and C3, by hydroxyl is witnessed), and ir spectra, in tandem with the method of synthesis. Conversion of the four diols to their thionocarbonates, and subsequent treatment with triethyl phosphite at the reflux temperature, provides the structurally related olefins stereospecifically. Catalytic hydrogenation of 17 provides dl-bivalvane (2), whereas reduction of 19 gives rise to the meso-bivalvane isomer 3. Other aspects of these transformations and conformational possibilities for 2 and 3 are discussed. The dodecahedron is one of the five perfect solids (the others are the tetrahedron, cube, octahedron, and icosahedron) and consequently has been a source of fascination for mathematicians since the time of Pythagoras and Plato. Only recently, however, has the dodecahedrane molecule attracted the attention of synthetic chemists. Notwithstanding, this (CH)2o polyhedron, which is endowed with most intriguing geometry, remains an unknown Although several approaches to dodecahedrane are currently under investigation in these laboratories, attention is focused specifically herein on the fundamental aspects of that scheme which involves effective “dimerization” of two triquinacene halves. The essence of,this concept is not new, it having been advanced earlier in singular form by Woodward, Fukunaga, and Kelly2 who viewed dodecahedrane as composed of two triquinacene subunits which when properly arranged might be coaxed into sixfold carbon-carbon bond formation as illustrated in 1. That efforts along this