Synthesis of isoprenoid bisphosphonate ethers through C–P bond formations: Potential inhibitors of geranylgeranyl diphosphate synthase

• Xiang Zhou,
• Jacqueline E. Reilly,
• Kathleen A. Loerch,
• Raymond J. Hohl and
• David F. Wiemer

Beilstein J. Org. Chem. 2014, 10, 1645–1650, doi:10.3762/bjoc.10.171

• alkoxide after formation of the bisphosphonate would face the strong possibility of phosphonate–phosphate rearrangement [15][16][17]. However, diethyl hydroxymethylphosphonate (7, Scheme 1) is known to react with a base and geranyl bromide to afford the ether 8 in good yield [18]. With compound 8 in hand

Addition of H-phosphonates to quinine-derived carbonyl compounds. An unexpected C9 phosphonate–phosphate rearrangement and tandem intramolecular piperidine elimination

• Łukasz Górecki,
• Artur Mucha and
• Paweł Kafarski

Beilstein J. Org. Chem. 2014, 10, 883–889, doi:10.3762/bjoc.10.85

• skeleton and a phosphorus atom. For the C9 ketones a phosphonate–phosphate rearrangement, associated with a tandem elimination of the piperidine fragment, was evidenced. Keywords: carbonyl derivatives; dialkyl phosphite addition; organophosporus; phosphonate–phosphate rearrangement; quinine oxidation

• chromatography, for details see Supporting Information File 1). C9 position modification, phosphonate–phosphate rearrangement Oxidation of the C9 hydroxy group of quinine to the corresponding ketone, quininone, was performed with potassium tert-butoxide and benzophenone (Scheme 4) [34]. Using toluene as the

• typical for phosphates, 13b: −5.76 and −5.49 ppm. Apparently, they were products of the phosphonate–phosphate rearrangement of intermediate hydroxyphosphonates [36][37][38]. Treatment of ketones 11 and 12 with dimethyl- and diphenyl phosphite brought quite similar results. The expected product, diphenyl