Charles R. Degenhardt

Recent work on the synthesis of phosphonate-containing, bone-active heterocycles

New approaches to the design and synthesis of bone antiresorptive phosphonates have led to the discovery of the cyclic bisphophonate series and the phosphonoalkylphosphinate heterocyclic series. The latter class, which offers substrates for interesting dianion chemistry, has been shown to include effective bone-active isosteres of the well-known bisphosphonates.

Orbital interactions in anti- and syn- tricyclooctadienes and their homoderivatives

Photoelectron spectroscopy and molecular orbital calculations of the Extended Hückel, MINDO/3 and STO-3G Hartree-Fock type have been applied to anti- and syn-tricyclo[4.2.0.02,5]octadiene (1 and 2) and their homo and bishomo derivatives. The resulting ordering of the one-electron levels for 1 and 2 are 7ag(π +), [6bu(σ), 5bu(π−)], 4au(σ), 3au(σ) and 7a1(π+), 5b2(σ), 6b2(π−), 3a2(σ), 4b1(σ), respectively. The present results differ substantially from those previously published.

Analysis of the thermodynamic and kinetic factors which control entry into, and Wagner–Meerwein rearrangement within, the C12H15+ systems

The relative kinetic and thermodynamic factors controlling the Wagner–Meerwein inter-relationship of the perhydromethenocyclopenta[a]pentalenyl brosylates (1a) and (2a) have been determined; the endo-brosylate (7a) was also examined and found to be unusually reactive for an endo-2-norbornyl derivative.