Improved Synthesis of C2-Symmetrical Pyridinediols and Synthesis of Cs-Symmetrical Pyridinediols

Base-induced reaction of 2,6-dimethylpyridine (2,6-lutidine) (1) with two equivalents of various ketones has been reported to provide C2-symmetrical pyridine diols 3. Closer examination reveals that competitive di-addition to a single methyl group can occur providing Cs-symmetrical pyridine diols 7. By varying the lithiation times, the formation of this side product could be maximized or minimized on the basis of a mechanistic proposal for the competing pathways. The formation of the Cs-diol 7 could be excluded completely by using potassium diisopropylamide as base; high yields of C2-symmetrical pyridine diols 3 are obtained. Regioselective additions of 1 to (R)-fenchone and (-)-menthone were also achieved.

Quark-Novae Ia in the Hubble diagram: Implications For Dark Energy

The accelerated expansion of the Universe was proposed through the use of Type-Ia SNe as standard candles. The standardization depends on an empirical correlation between the stretch/color and peak luminosity of the light curves. The use of Type Ia SN as standard candles rests on the assumption that their properties (and this correlation) do not vary with red-shift. We consider the possibility that the majority of Type-Ia SNe are in fact caused by a Quark-Nova detonation in a tight neutron-star-CO-white-dwarf binary system; a Quark-Nova Ia. The spin-down energy injected by the Quark Nova remnant (the quark star) contributes to the post-peak light curve and neatly explains the observed correlation between peak luminosity and light curve shape. We demonstrate that the parameters describing Quark-Novae Ia are NOT constant in red-shift. Simulated Quark-Nova Ia light curves provide a test of the stretch/color correlation by comparing the true distance modulus with that determined using SN light curve fitters. We determine a correction between the true and fitted distance moduli which when applied to Type-Ia SNe in the Hubble diagram recovers the Omega_M = 1 cosmology. We conclude that Type-Ia SNe observations do not necessitate the need for an accelerating expansion of the Universe (if the observed SNe-Ia are dominated by QNe-Ia) and by association the need for Dark Energy.Comment: 22 pages, 6 figures. Accepted for publication in Research in Astronomy and Astrophysic