Darstellung und 1H-NMR-spektroskopische Untersuchungen von β-substituierten Äthylen-diphenylphosphinoxiden

Preparation and ¹H-N.M.R. Spectroscopic Investigation of β-Substituted Ethylene Diphenylphosphine Oxides The diphenyl ester 1d of diphenylphosphinyl-methanephosphonic acid in benzene reacts regiospecifically with aldehydes, in presence of strong bases, to β-substituted ethylene diphenylphosphine oxides 4 . The yields are satisfactory on a preparative scale. The ABX type H-n.m.r. spectra of compounds 4 were analysed. The isolated pure products 4 exhibit trans configuration, characterized by the specific signal sequence of the ethylene proton H_B which in some cases could be separated by use of shift reagents. The cis or trans configuration of compounds 4 can be referred partially to steric hindrance in the transition state of the second reaction step.     

β-Thiocyanatovinylcarbonylverbindungen. IV. Darstellung und Reaktionen der 2-Thiocyanatomethylen-cycloalkanone-(1)

β-Thiocyanato-Vinylcarbonyl Compounds. IV. Preparation and Reactions of 2-Thiocyanatomethylene-cycloalkanones-(1) 2-Thiocyanatomethylene-cycloalkanones-(1) 2 were obtained from the corresponding 2-chlormethylene-cycloalkanones-(1) 1 . On reaction with substituted phenylhydrazines, the 2,4-dinitrophenylhydrazones 4b, 4c and 4e , 1,2,3-thiadiaziniumperchlorates 5a and 5a ′, and the substituted pyrazoles 7e and 7f , were isolated, respectively. From reaction of 2 with liquid ammonia, the isothiazoles 8a and 8b as well as the bis-(2-acyl-vinyl)-sulfides 9c and 9f were obtained.     

β-Thiocyanatovinylcarbonylverbindungen. III. 1H-NMR-Untersuchungen an β-Thiocyanato-vinylaldehyden

β-Thiocyanato-vinyl-carbonyl Compounds. III ¹H-NMR Investigations of β-Thiocyanato-vinylaldehydes The ¹H-NMR spectra of some alkyl- and phenylsubstituted Z/E-isomeric β-thiocyanato-vinylaldehydes are represented. The assignment for Z/E-isomers is made using the chemical shifts of the CHO-protons and paramagnetic shift experiments. The discussion of the ΔEu-values allows to determine the conformation of the CHO-group. The main products in the case of the alkyl-substituted β-thiocyanato-vinylaldehydes are the Z-isomeric compounds which fact is attributed to mechanistic and electronic effects.     

β-Thiocyanatovinylcarbonylverbindungen. XI. Ungewöhnliche Substituenteneffekte bei der massenspektrometrischen Fragmentierung von β-Thiocyanatovinylaldehyden

β-Thiocyanatovinylcarbonyl Compounds. XI. Unusual Substituent Effects in the Mass-spectrometrical Fragmentation of β-Thiocyanatovinylaldehydes The mass spectra of homologous Z/E-isomers and constitutional isomers of β-thiocyanatovinylaldehydes are discussed. The main fragmentation consisting of HCN-loss from the molecular ion is influenced by the substituents so that the constitutional and steric isomers can be clearly distinguished by the \documentclass{article}\pagestyle{empty}\begin{document}$ {\rm M - HC}\left. {\overline {\, {\rm N} \,}}\! \right| + /{\rm M + }^ \cdot $\end{document} ratio. Alkyl homologues with a hydrogen atom in γ-position to the aldehyde group show an unusual intensive CN-radical loss due to a „hidden hydrogen rearrangement”︁, which was proved by deuteration experiments.     

Darstellung und 1H-NMR-spektroskopische Untersuchung von β-substituierten Äthylen-phenylphosphinsäure-äthylestern

Preparation and ¹H N.M.R. Spectroscopic Investigation of β-Substituted Ethyl Esters of Ethylene-phenylphosphinic Acid The ethyl ester 3 of diphenylphosphorylmethyl-phenyl-phosphinic acid in benzene reacts regiospecifically and stereoselectively with aldehydes, in presence of sodium hydride, to 2-substituted ethyl esters of trans-ethylene-1-phenylphosphinic acid 8 (E-isomers) in satisfactory yields. The ABX type H-n.m.r. spectra of isolated pure products 8 were analysed. The trans configuration of these compounds is characterized by the specific signal sequence of ethylene proton H_B.     

Steroide. XLVI. Darstellung von 15.16.17-trisubstituierten Steroiden durch Ringöffnung von 17β-substituierten 15β.16β-Epoxy-östra-1.3.5(10)-trien-3-methyläthern

Steroids. XLVI. Preparation of 15,16,17-Trisubstituted Steroids by Ring Cleavage of 17β-Substituted 15β,16β-Epoxy-estra-1,3,5(10)-triene 3-Methylethers The ring cleavage of 15β.16β-epoxy-3-methoxy-estra-1-3,5(10)-triene-17β-ol 1a with strong nucleophiles occurs mainly at C-16, yielding 16α-substituted 15β,17β-diols 2a–f . Besides this, 1a is cleaved to a small extent at C-15, yielding the 15α-substituted 16β,17β-diols 3a—f and the Δ¹⁴-16,17β-diol 5a . The structures have been elucidated by means of i.r., H-n.m.r. and mass spectroscopy.     

Darstellung und Reaktionen von β-Oxosulfenylchloriden. II. Direkte Chlorsulfanylierung von disubstituierten Acetaldehyden mit Schwefeldichlorid

Preparation and Reactions of β-Oxosulfenyl Chlorides. II. Direct Chlorosulfenylation of Disubstituted Acetaldehydes by Sulfur Dichloride The reaction of dialkylacetaldehydes ( 1a , b ) with sulfur dichloride yields the corresponding β-oxosulfenylchlorides ( 2a , b ). Examples for addition- and substitution-reactions of 2a , b are described.     

β-Fur-2-yl-α-halogenacrylonitrile. I. Darstellung von β-Fur-2-yl-ß-aminoacrylonitrilen und β-Fur-2-yl-α-aminoacrylonitrilen

β-Fur-2-yl-α-halogenacrylonitriles. I. Preparation of β-Fur-2-yl-ß-aminoacrylonitriles and β-Fur-2-yl-α-aminoacrylonitriles β-Fur-2-yl-α-halogenacrylonitriles 1 react with secondary amines to yield β-fur-2-yl-ß-aminonitriles 2 and β-fur-2-yl-α-aminoacrylonitriles 3 . The ¹ H-n.m.r. spectra of the E/Z isomers are discussed.     

Darstellung und Reaktionen von α-Halogenbenzyl-silanen

Preparation and Reactions of α-Halogenobenzyl-silanes α-Bromobenzyl-dimethylchlorosilane 3 , bis-(α-bromobenzyl)-dimethylsilane 8 and the corresponding α-chlorobenzyl-compounds 5 and 13 have been prepared by reaction of benzyl-dimethylchlorosilane 1 resp. dibenzyl-dimethylsilane 2 with N-bromosuccinimid and sulfurylchlorid. The α-halogenobenzyl-dimethylchlorosilanes 3 and 5 have been treated with water, alcohols and phenol, to give the corresponding silanols 15 and 16 , siloxanes 17 and 18 , alkoxy- and phenoxysilanes 19 and 20 . Reactions of 3 with brenzcatechin, o-aminophenol and o-aminobenzylalcohol give 6- resp. 7- membered silaheterocycles 21 – 23 .     

Darstellung von schwer entflammbaren polymeren unter verwendung von β-trichlormethyl-β-lactonen und deren derivate

By using β-trichloromethyl-β-lactones it is possible to incorporate the CCl₃-group into various classes of polymers. This can be achieved either via ringopening copolymerization or by using the adducts of these lactones with amines, alcohols or phenols in polycondensation or polyaddition reactions. Under suitable reaction conditions block- or graft-copolymers can be obtained. Finally, derivatives of β-trichloro-β-propiolactones can be used for the incorporation into polymers after or during polymerization. Polymers containing CCl₃-groups are flame resistant or selfextinguishing. Often, these effects are observed at lower chlorine contents than normally necessary with other chlorinated flame retardants.     

Darstellung von β-substituierten trans-Ethylen-diphenylphosphinen und -sulfiden durch P(O)- und P(S)-aktivierte Olefinierung

Preparation of β-Substituted trans-Ethylene Diphenylphosphines and Sulphides by P(0) and P(S)-activated Olefination Methylene bis-diphenylphosphine monoxide ( 3c ) in tuluene reacts regiospecifically and stereoselectively with aldehydes in the presence of potassium tert-butoxide to ß-substituted transethylene diphenylphosphines 6 , which can be oxidized to the sulphides 2 by sulphur in acetone. These sulphides 2 are to be obtained also directly from methylene bis-diphenylphosphine oxide sulphide 3b and methylene bis-diphenylphosphine disulphide 3d , respectively, under the same olefination conditions. But the yields are smaller and the purification of the raw products is much more difficult, if 3d is used.