The 3-Methyl-1,3-butadienyl Phenyl Sulfoxide II. Utilization as a Michael Acceptor of Lithiated Protected Cyanohydrins. Syntheses of Tagetones and Ocimenones

In contradistinction to the α, β-unsaturated sulfoxides, few reports have been published on the Michael reactivity of the α,β-γ,δ-diunsaturated sulfoxides¹. We present here the details of our investigation on the title sulfoxide 5 as a reagent for the synthesis of terpenoid polyenones.     

Preparation and Pyrolysis of Cyclooctyl Phenyl Sulfoxide

We recently reported a facile synthesis for bicyclo-[n.2.0]alkanediols of the general structure 1. ¹ The recent demonstration² that cis-bicyclo[3.2.0]heptane-1,7-diol(3) can be converted to the novel, highly-strained trans-bicyclo[4.1.0]heptane system increases the interest in this class of compounds. Comparison of our diols with materials used by Paukstelis and Kao in the rearrangement studies² and further work in our laboratory has shown that the diols reported in our initial communication are trans-diols and should be assigned structures 4 and 5.     

Alkatrienyl Sulfoxides and Sulfones. Part I. 3-Methyl-1,2,4-pentatrienyl Phenyl Sulfoxide-Synthesis and Electrophile-Induced Cyclization Reactions

A method for the synthesis of the 3-methyl-1,2,4-pentatrienyl phenyl sulfoxide 3 by [2,3]-sigmatropic rearrangement of the 3-methyl-1-penten-4-yn-3-yl benzenesulfenate 2 , formed in the reaction of the 3-methyl-1-pentene-4-yn-2-ol 1 with phenylsulfenyl chloride has been created. Possibilities and restrictions of the five-membered heterocyclization in electrophile-induced reactions leading to the synthesis of the 5H-1,2-oxathiol-2-ium salts 5 , 7 , and 8 have been explored. Chlorination of the sulfoxide 2 proceeded with formation of the (E)-2-chloro-3-methylene-1,4-pentadienyl phenyl sulfoxide 4 , while the bromination afforded the 4-bromo-5H-1,2-oxathiol-2-ium bromide 5 , which after reflux in 1,2-dichloroethane eliminated hydrogen bromide and was transformed into the (E)-2-bromo-3-methylene-1,4-pentadienyl phenyl sulfoxide 6 .     

The Anion of 3-Methyl-2-pyridin-4-yl- 1,3-oxazine

Abstract

n-Butyllithium at ?78°C readily abstracts the methine proton from the title compound. The anion reacts efficiently with a range of electrophiles to provide 4-pyridyl ketones upon acid hydrolysis.     

On the Preparation of 4-Hydroxymethyl-5-Methyl-1,3-Dioxol-2-One

A practical and efficient conversion of 4-bromomethyl-5-methyl-1, 3-dioxol-2-one 1 into the corresponding carbinol 2, a useful building block for the preparation of prodrugs, is reported.     

1,3-Dipolar Cycloaddition of 5-Substituted-1-Methyl-3-Oxidopyridiniums

5-Methoxy- and 5-dimethylamino-1-methyl-3-oxidopyridiniums were shown to give the 1,3-dipolar cycloadducts widely with methyl acrylate, acrylonitrile, N-phenylmaleimide, styrene, phenylacetylene, cyclopentadiene, cyclopentene, diethyl azodicarboxylate and singlet oxygen.     

Reaction of 1, 1-Bis(Methylthio)-3-Methyl-1, 3-Butadiene with Lithiated 3-Methyl-2-Butenyl Phenyl Sulfide. A Special Case of Cyclopropane Formation

Abstract

The conjugated ketene dithioacetal 2 is now available by three different procedures¹. This electrophilic isoprene compound has been shown to add smoothly some simple lithio derivatives, but the addition of 3-methyl-2-butenyl-lithium gave a product with total inversion of the starting allylic chain^1a.     

Preparation,Thermolysis, and Photolysis of Some New Thiophosphoramidates Derived from 3-Methyl-2-Benzothiazolinone Hydrazone

3-Methyl-2-benzothiazolinone hydrazone (1) reacts with dialkyl phosphorothiochloridates 2a,b in the presence of a base, to give the respective dialkylthiophosphorylated hydrazones 3a,b. Upon thermolysis, compound 3b yields bi(3-methylbenzothiazole-2-iminyl) (4). Exposure of 3b to sunlight in methanol results in the formation of 3-methyl-2-benzothiazolinone (5). When the same experiment was carried on the starting hydrazone 1, bis(3-methyl- benzothiazole-2-iminyl)diazine (6) was formed. Elemental analyses and spectroscopic details are presented for the new compounds.

Supplemental materials are available for this article. Go to the publisher's online edition of Phosphorus, Sulfur, and Silicon and the Related Elements to view the free supplemental file.     

Efficient Large-Scale Preparation of Phenyl 3-Pyridazinyl Ketone1

A convenient approach to phenyl 3-pyridazinyl ketone 4 permitting economical large scale preparation is proposed. Commercially available 3,6-dichloropyridazine 1 serves as the starting material in the three-step process.     

Extraktion von Metallionen durch aromatische Sulfoxide. I

Zusammenfassung Die vorliegende Arbeit enthält eine Untersuchung der Möglichkeiten zu extraktionschromatographischen und extraktiven Trennungen, die sich aus der unterschiedlichen Solvatation von Metall-spezies durch Dibenzyl- und Diphenylsulfoxid ergeben. Die durch Papierchromatographie mit umgekehrten Phasen ermittelten R_f-Spektren von 50 Ionen im Dibenzylsulfoxid-HNO₃-System und von 34 Ionen im Diphenylsulfoxid-HNO₃-System geben einen Überblick über die Trennmöglichkeiten.Die Extraktion von Salpetersäure und die Extraktion von Uranylnitrat aus salpetersauren, wässerigen Phasen in Lösungen der beiden Sulfoxide in Benzol wurde in Batchversuchen untersucht. Beide Sulfoxide extrahieren Salpetersäure als 1 1-Komplex. Anstiegsanalysen ergaben für die durch Dibenzylsulfoxid aus salpetersauren Lösungen extrahierten Spezies von U(VI), Th(IV), Pd(II), Au(III) und Tl(III) die Solvatationszahl 2.

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Extraction of metal ions by aromatic sulfoxides. I

Summary The present work comprises a study of the possibilities with regard to the chromatographic and extractive separations that result from the differing solvation of metal species by means of dibenzyl- and diphenyl sulfoxide. The R_f-spectra found for 50 ions in dibenzyl sulfoxide-nitric acid system when subjected to paper chromatography with inverted phases and of 34 ions in the diphenyl sulfoxide-nitric acid system yield a survey of the separation possibilities.The extraction of nitric acid and the extraction of uranyl nitrate from nitric acid aqueous phases in solutions of the two sulfoxides in benzene was studied in batch trials. Both sulfoxides extract nitric acid as the 1 1 complex. Ascending analyses gave the solvation number 2 for the species U(VI), Th(IV), Pd(II), Au(III) and Tl(III) extracted from nitric acid solutions by means of dibenzylsulfoxide.

     

The Synthesis and Photoisomerization of 5-Methyl-5-Vinyl-1,3-Cyclopentadiene

A versatile scheme for the synthesis of geminally disubstituted cyclopentadienes is used to prepare the title compound 4 . This remarkably stable vinyl-cyclopentadiene, distinguished by its C_s symmetry, undergoes exclusively electrocyclic ring closure upon direct π–π* excitation at 254 nm. The epimeric vinyl-housenes 11 and 12 , which, for geometric reasons, are insensitive to the walk rearrangement, are suggested to be the primary photo-products. One of them, 12 , due to its syn-oriented vinyl group, undergoes spontaneous copy rearrangement to give 2-methylbicyclo[3.2.1]hepta-2,6-diene ( 13 ). The other, 11 , having an anti-oriented vinyl group, can only undergo thermal return to the starting material 4 . Whereas no leakage to a 1,5-vinyl migration is discernible for the S₁ state of 4 , the benzophenone-sensitized photolysis at 350 nm is shown to be governed by this rearrangement. 1-Methyl-5-vinylcyclopenta-1,3-diene ( 14 ), the unstable primary product of the sensitized photoreaction, is trapped by 4-phenyl-3H-1,2,4-triazole-3,5(4H)-dione (PTAD).     

Easy Preparation of 1,3-Di-tert-Butylbenzene and Some Derivatives Thereof

1,3-Di-tert-butylbenzene (4) can conveniently be prepared from 1-bromo-3,5-di-tert-butylbenzene (2) which, in turn, is obtained from the easily available 1,3,5-tri-tert-butylbenzene (1). The use of 4 is illustrated by the preparation of the arylphosphines 6 and 7.     

Paradoxes in Thermal Stability of the Liquid-Crystal Phase of Phenylpropargyl Phenyl Ethers: I. Synthesis and Mesogenic Properties of Phenylpropargyl Phenyl Ethers

The ethers PhCCCH₂OC₆H₃RR' were prepared in 51-83% yields by reactions of phenylpropargyl tosylate in alkaline solution with appropriate p- and o-substituted phenols. Below are given R, R', and the ranges of existence of the nematic mesophase (°C): p-I, H, 104-137; p-Cl, H, 65-117; p-F, H, 33-53; p-OMe, H, 79-120; H, H, 44-115; p-(Me)₃C, H, 74-82; p-COOH, H; p-NO₂, H, 77-96; o-NO₂, H, 83-139; o-CHO, H, 75-115; p-Br, o-NO₂, 95-132; p-Cl, o-NO₂, 71-123; p-F, o-NO₂, 79-120; o-Cl, H, none; p-COOPr, H, none; and p-COOPh, H, 116-134. In contrast to the traditional views, the presence of the o-nitro group enhances, rather than distorts, the thermal stability of the mesophase. The stability increases in parallel with the -R effect of the o-substituent.     

The Phase Transfer Catalysed Preparation of 2-Methyl-2-Trichloromethyl-3-Phenyloxirane

A phase transfer catalyst has been used to prepare the title compound and other highly chlorinated compounds from phenylpropanone and carbon tetrachloride.     

Modern Advances in the Preparation of Phenyl Benzoate Derivatives and Their Applied Properties

Russian Journal of General Chemistry - Published data on methods for the preparation of liquid crystalline phenyl benzoate derivatives were summarized. The results of studies on the mesomorphic...     

Preparation of 6-(nitron-c-yl)- and 6-(1,3-butadienyl)-2-pyrones and their cycloaddition reactions

6-(N-Substituted nitron-C-yl)-2-pyrones 1 and 6-(4-substituted 1,3-butadienyl)-2-pyrone 2 were prepared and their cycloaddition reactions with three kinds of diene systems were investigated. Namely, the reactions of 1 with methyl acrylate, vinyl crotonate and divinylsulfone took place at the nitrone moiety to afford 3-substituted isoxazolidines 9–14 , and that of 2 with maleimide took place at the 2-pyrone moiety to give a bis-adduct 17 via elimination of carbon dioxide.