G. Kovács

Reductive formation and transformation of epoxides in neutral aqueous medium

Abstract Stoichiometrically controlled reductive epoxidation could be elaborated to transform α,β-diketones or α-hydroxy ketones to epoxides in a very good yields in neutral aqueous medium using chromium(II)acetate. Modification of the coordination sphere of Cr(II) ion with the added ligand makes the reductive ring-opening possible.

Synthesis of stable prostacyclin analogues

Abstract The synthesis of novel, stable PGI2 analogues, 4-oxoprostacyclin methyl ester / 8 a/ and its congeners is described here; the key step of the procedure is a Knoevenagel condensation between hemiacetal 5 and the sulfindes 3 or sulfoxides 4 .

A convenient short synthesis of 7-oxo-PGI2

Abstract A 5-step synthesis of the title compound via selective hydroxylation of Δ 6 -PGI 1 derivative is presented including stereochemistry and conformational analysis of intermediates.

Synthesis of prostacyclin analogues via knoevenagel condensation

Abstract A novel, simple procedure is described for the synthesis of prostacyclin analogues starting from the hemiacetal 1 and active methylene compounds.

Remote OH-group directing effect in the stereochemistry of intramolecular alkoxide addition to conjugated double bond

Abstract Preferential formation of less stable (endo) product in intramolecular Michael reaction is explained by the participation of structurally remote OH group in the transition state.