Ryszard Kinas

Stereospecific synthesis of adenosine 3′,5′-(SP)- and -(RP)-cyclic phosphorothioates (cAMPS)

NNO 2 ′-Tribenzoyladenosine 3′,5′-cyclic phosphate (3) was converted into a diastereoisomeric mixture of NNO2′-tribenzoyladenosine 3′,5′-cyclic phosphoranilidates (4); after separation of these diastereoisomers, the corresponding adenosine 3′,5′-cyclic phosphorothioates (1, cAMPS) were obtained and the absolute configuration at the P atom in the diastereoisomers of (4) and (1) was established by 31P n.m.r. spectroscopy.

Enantiomeric 2-anilino-2-oxo-1,3,2-oxazaphosphorinanes: Synthesis and NMR-investigation of their non-racemic mixtures

Abstract Enantiomeric R-(−)- and (S)-(+)-2-anilino-2-oxo-1,3,2-oxazaphosphorinanes ( 1 ) have been synthesized by catalytic debenzylation of separated diastereomers of 3-(α-methylbenzyl)-2-anilino-2-oxo-1,3,2-oxazaphosphorinanes. Self-induced diastereomeric anisochronicity in non-racemic mixtures of these enantiomers was shown to vary with enantiomeric composition, overall specimen concentration, and temperature. The equilibrium constants of monomer-dimer and homo-cross-associate diastereomeric equilibria are estimated for the first time.

31P-15N coupling constants and 15N/14N isotope effects on 31P NMR chemical shifts of 2-phenylamino-2-oxo(-thioxo, -selenoxo)-4-methyl-1,3,2-dioxaphosphorinanes and related compounds

The strong influence of a chalcogen atom (O, S, Se) attached to phosphorus on the spin-spin coupling constant 1J(P-15N) in the family of diastereoisomeric 2-|15N] -phenyl-amino-2X(X = O, S, Se)-4-methyl-l,3,2-dioxaphosphorinanes is demonstrated. The 15N/14N isotope effect on the nuclear shielding of phosphorus-31 is larger for the shorter equatorial than for the longer axial P-N bonds.

Reinvestigation of the reaction between sodium diethyl phosphite and diethyl phosphorochloridate. Evidence for a SET process in the formation of a direct P(IV)P(IV) bond

Abstract Alkali metal salts of diethyl phosphites act as nucleophiles or electron donors in reactions with diethyl phosphorochloridate. Evidence is provided that formation of the direct P(IV)P(IV) bond proceeds via a single electron transfer process (SET) from phosphite anion to phosphorochloridate.

Synthesis of Some Substituted 1,3,2-Oxazaphosphorinanes

Abstract To study the effect of statistically controlled associate dia-stereoisomerism (SCADA), the optical isomers of some derivatives of 2-amino-2-oxo-1,3,2-oxazaphosphorinane, containing the residues of L-α-aminoacids, were synthesized. The magnitude of chemical shift nonequivalence (Δδ) in 31P NMR-spectra of diastereomeric mixtures was maximum for isomeric derivatives of valine; the dependence of Δδ31P on their concentration was investigated.

31P NMR Kinetic Studies of Alkylation Chemistry of N,N′-Bis(2-Chloroethyl)Phosphordiamidic Acid and Its Congeners

Abstract Ifosfmide (I), like isomeric cyclophosphmide, belongs to the most eZfective anticancer drugs currently in clinically therapeutic use. It has been demonstrated that I require metabolic activation to exert its cytotoxic activity.