A. Zatorski

Organosulphur compounds—XVIII1: A new and general synthesis of ketene s,s- and o,s-thioacetals based on the horner-wittig reaction

Abstract A new and general synthesis of ketene S,S-thioacetals ( 1 ) and ketene O.S-thioacetals ( 6 ) which involves the Horner-Wittig reaction of carbonyl compounds with the metallated S,S- and O,S-thioacetals of formyl-phosphonates ( 4 and 5 ) is described. The Horner-Wittig reaction of 4 with aromatic aldehydes can be carried out under two-phase conditions. The generation of the carbanions from 4 and 5 as well as the course of their reaction with carbonyl compounds were studied by the low temperature 31 P NMR spectroscopy. It was found that S,S-thioacetals of formylphospbonates ( 4 ) are very easily metallated in contrast to O,S-thioacetals of formyl-phosphonates ( 5 ) which form the lithium derivatives only on treatment with t-butyllitnium. No evidence was obtained from 31 P NMR spectra supporting the formation of the lithium derivatives of 0,0-acetals of formyl-phosphonates ( 12 ).

Reaction of 5,5-diphenyl-2-thiohydantoin with 1,3-dibromopropane under phase transfer catalytic conditions : Crystal and molecular structure of 2,3,4,5-tetrahydro-7,7-diphenylimidazo-[2,1-b]-thiazine -6(7H)-one

Abstract The reaction of the potassium salt of 5,5-diphenyl-2-thiohydantoin with 1,3-dibromopropane and triethylamine carried out under phase transfer catalytic conditions gave almost quantitatively two isomeric diphenylimidazothiazine 2 and 3 in a ratio ca 1:2. 2,3,4,5-Tetrahydro-7,7-diphenylimidazo- [2,1-b]-thiazine-6(7H)-one (3) crystallises from DMSO in the space group P212121 with a = 8.488(3), b = 11.682(4), c = 15.522(5)A. The 6-membered thiazine ring in 3 adopts a sofa conformation.

REACTION OF 5,5-DIPHENYL-2-THIOHYDANTOIN WITH 1,4-DIBROMOBUTANE. THE CRYSTAL AND MOLECULAR STRUCTURE OF 2,3,4,5-TETRAHYDRO-7,7-DIPHENYLIMIDAZO-[2,1-b]-THIAZEPINE-8(7H)-ONE

Abstract The reaction between the potassium salt of 5,5-diphenyl-2-thiohydantoin (1) and 1,3-dibromopropane carried out in DME under anhydrous conditions has been found to give two isomeric diphenylimidazothiazines 2 and 3. When the reaction of 1 with 1,3-dibromopropane was performed in protic solvents (EtOH, HOH, NaOH) 2 and 3-(3-mercaptopropyl) - 5,5 - diphenylthiohydantoin (4) were formed. The latter is the product of hydrolysis of 3 taking place under the reaction conditions. 2,3,4,5 - Tetrahydro - 6,6 - diphenylimidazo [2,1-b] - thiazine - 7 (6H) - one (2) crystallises in space group P21/n with a =10.812(3), b =14.905(7), c =9.885(4) A, β = 104.91(2)°. The 5-membered ring in 2 is planar whereas the 6-membered thiazine ring adopts the sofa conformation.

Organosulphur compounds—IX: NMR and structural assignments in α,β-unsaturated sulphoxides using additive increments method

Abstract Additive shielding increments for the sulphinyl group, RS(O)-, have been estimated (ZRSO-gem 1·27; ZRSO-cis 0·67; ZRSO-trans 0·41) and their utility in making NMR structural assignments in α,β-unsaturated sulphoxides is presented.

Reaction of 5,5-diphenyl-2-thiohydantoin with 1,2-dibromoethane.crystal and molecular structures of 2,3-dihydro-6,6-diphenylimi-dazo-[2,1-b]-thiazol-5(6h)-one and 2,3-dihydro-5,5-diphenylimi-dazo-[2,-1-b]-thiazol-6(5h)-one and their reactivity

Abstract The crystal and molecular structures of the title isomeric compounds 1 and 2 , obtained by intramolecular N,S--dialkylation of 5,5-diphenyl-2-thiohydantoin with 1,2-dibro-moethane, have been determined from X-ray diffractometer data. 2,3-Dihydro-6,6-diphenylimidazo-[2,1-b]-thiazol-5(6H)-one 1 crystallizes in space group P212121 with a=11.376(3), b=12,255(5), c=8.434(3) A and Z=4. Crystals of 2 , containing one molecule of benzene, are monoclinic,space group P21/c with a=11.539(6), b=10.242(3), c=16.353(5) A, β=95.45(5)° and Z=4. In both cases a planar geometry of the two fused five-membered heterocyclic rings was found. The selected bond lengths in 1 and 2 , as well as those analogous imidazothiazinones 3 and 4 , were used to calculate EHOSE (Harmonic Oscillation Stabilization Energy). The problem of stability and chemical reactivity of compounds 1 to 4 is also discussed.

Synthesis of Some Biologically Active Cyclopente-Nones using New Organophosphorus Reagents

Abstract The use of organic phosphorus and sulfur compounds in the general synthesis of biologically active functionalized cyclopentenones is presented.

Application of the additive increments method to the calculation of chemical shift of olefinic protons in aromatic olefines: Additive increments for para and meta substituents in the aromatic ring

Abstract Additive increments for para and meta substituents in the aromatic ring were calculated on the basis of 332 examples of chemical shifts and were correlated with Hammetts constants. Examples of calculation of chemical shifts of olefinic protons in substituted aromatic olefines by means of the increments are given.

(α-Phosphoryl Carbanions. Searching of Course of Wittig-Horner Reaction by 31P Low Temperature NMR

Abstract Continuing our studies on utilization of the Wittig-Horner reaction in organic synthesis, we have examined reactivity of α-lithium derivatives of several phosphonates towards carbonyl compounds, by 31P NMR at low temperature (from -100°C to r.t.). The chemical shifts δ [ppm] of a few representative phosphonates (1), carbanions (2) and betains (3) will be given.