1,7-RAMBERG-BÄCKLUND REACTIONS AND OTHER ANOMALOUS REACTIONS OF P-HYDROXYPHENYL α-HALO SULFONES

Abstract

p-Hydroxyphenyl α-halo sulfones are unusual in several respects. For example, p-hydroxyphenyl α-chloroisopropyl sulfone has no α′-H, however, when heated with one equivalent of base it undergoes a 1,7-elimination reaction via a pathway usually associated with the 1,3-elimination step of Ramberg-Bäcklund reactions.     

A STUDY OF THE REACTIONS OF BENZYL ETHERS WITH DIBROMOCARBENE

Using potassium carbonate as base and a polyethylene glycol with an average molecular weight of 600 (PGE600) as phase transfer catalyst, reaction of benzyl ethers with dibromocarbene leads to benzylic C—H bond insertion products, aromatic aldehydes are also formed as one of the products.     

DEHYDROCHLORINATION OF α-CHLORO SULFONES WITH KOH-T-BUOH: KINETIC VS EQUILIBRIUM CONTROL OF THE FORMATION OF α, β-UNSATURATED SULFONES AND THE β-T-BUTOXY AND β-HYDROXY MICHAEL ADDUCTS

Abstract

Inorganic sulfur compounds are used by microorganisms (bacteria, fungi, algae) and plants for assimilation, i.e. biosynthesis of sulfur-containing cell constituents.

Quantitatively, within the biogeochemical cycle of sulfur the utilization of inorganic sulfur compounds in bacterial energy metabolism, i.e. dissimilatory sulfur utilization, is of far higher importance. Reduced sulfur compounds serve as electron donors for photosynthesis and respiration, whereas inorganic sulfur compounds of oxidation levels above sulfide serve as electron donors in anaerobic respiration as well as in fermentation. In still other bacteria reduced sulfur compounds act as protective agents against hydrogen peroxide.     

THE STUDY ON TRE KINETICS AND MECHANISM OF THE REACTIONS OF METAL IONS WITH PnAO

The kinetics and the mechanism of the formation reactions ofM(PnAO)~(2+)(M=Ni,Co,Cu)were studied with UV Spectrophotometer and StoppedFlow Spectrophotometer and a three steps mechanism was suggested.     

KINETIC STUDY OF THE POLYCONDENSATION OF 9-AMINO-NONANOIC ACID

9-Amino-nonaneic acid was polycondensed in boiling paraffin hydrocarbon medium, the water formed during the reaction was immediately carried away by the vapor of the medium. By using this technique, polycondensation ran very rapidly, and within 15 min. the extent of reaction (p) reached more than 95%, and after 3 hrs., p surpassed 99%. The number average molecular weight was higher than 40,000. These have never been reached as reported in literature.Because p can be pushed to over 99%, it is possible to study the complete course of polycondensation reactions. It was found that the reaction followed second order from the beginning up to p around 99%. Beyond this, the system became so viscous that a viscosity factor should be considered. This caused the reaction to be changed to third order.     

A THEORETICAL STUDY OF MECHANISMS IN THE PHOTOCHEMICAL REACTIONS OF FORMING XETENE AFTER THE α-EOND RUPTURE IN CYCLCHEMANONE

ab initio,SCF+CI calculations of the potential energy surfaces and barries in the various paths are presented for the chemical reactions of forming ketene after the a-bond rupture in cyclohexanone,using acetaldehyde as model.The possibilities of the various paths and thansition states of the important paths are discussed.     

SYNTHESIS OF N,N''''-DISUBSTITUTED MONOTHIOXAMIDE AND STUDY OF THEIR REACTIONS WITH DIAMINES

In this paper, six N,N'-disubstituted aonothioxamides were synthesized and the reactions between these monothioxamines and diamines (1,2-diamino ethane and 1,3-diamino propane) were studied. Some new compounds were synthesized by using these reactions.     

THE STUDY OF COPOLYMERIZATION OF p-DIETHYNYLBENZENE WITH OTHER ACETYLENIC DERIVATIVES

The copotymerizations of p-diethynyibenzene(PDEB)with phenytacetylene(PHA),4,4'-diethynytbiphenyt(DEBP)or m-diethynylbenzene(MDEB)are studied in various mole ratios of monomers.The sotubitity pa-rameter(σ_p),swellabitity(θ_p),Huggins parameter(X),density (d_4~(25))and the average motecutarweights between crosstinkof obtained copotymers are measured.The IR spectra of these copolymersare recorded.The mechanism about the polymerization of acetytenic derivatives initiated by(Ph_3P)_2PdCl_2is discussed.     

A CIDNP STUDY OF THE PHOTOREACTIONS OF METHYLFURANS WITH CHLORANIL

The CIDNP observations indicated that photoreaction of methylfurans with chloranilresulted not only furylmethyl hydroxyphenyl ethers via radical pairs but inducedfuryl radical isomerization to the derivatives of cyclopropene,propadiene and pyran.     

CHRONOABSORPTOMETRY FOR THE DETERMINATION OF KINETIC PARAMETERS OF ELECTRON TRANSFER REACTIONS USING LONG-OPTICAL-PATH ELECTROCHEMICAL CELL

A single potential step chronoabsorptometric method for the determination of ki-netic parameters of simple quasi-reversible reactions is described.It is verified by determiningthe kinetic parameters for the electroreduction of ferricyanide.A long-optical-path electro-chemical cell with a plug-in electrode is used.The thickness of solution layer is 0.55 mm     

KINETIC STUDY ON THE EXTRACTION OF PALLADIUM(Ⅱ) WITH BIS(2-ETHYLHEXYL)SULFIDE

The effects of concentration, temperature, stirring rate and specific interfacial area onthe extraction of Pd (Ⅱ) with bis(2--ethylhexyl) sulfide (DEHS) were studied by the use of aconstant interracial area cell. The results support an interracial chemical reaction regime.     

STUDY ON THE KINETIC ENERGY BUDGET OF A TYPHOON——BUDGETS OF KINETIC ENERGY IN GENERAL FLOW AND EDDY KINETIC ENERGY

The present paper studies the budgets of kinetic energy in general flow and eddy kinetic energy of Typhoon No. 7, 1975, with a special emphasis on the effects of the divergent and non-divergent winds on the generatioan and transport of kinetic energy. It has been found that:(1) As the typhoon developed and intensified, the generation of kinetic energy of di-vergent wind decreased relatively while that of non-dlvergent wind significantly increased and eventually became the primary term of the generation of kinetic energy. For the entire life spau of the typhoon, the generation of kinetic energy of divergent flow is the primary source of kinetic energy (4W/m~2) with the production of kinetic energy by non-divergent wind being only 0.5 W/m~2.(2) For the budget of eddy kinetic energy, at the initial stage a large amount of eddy kinetle energy needed to be imported from the region outside the typhoon, and at the mature stage a significant amount of eddy kinetic energy was exported. The terms of the work made     

THE THEORETICAL STUDIES OF PRODUCT ALIGNMENT OF THE REACTIONS OF Na,F WITH CH_3I

The NaI and IF product rotational alignment of the reactionsof Na,F+CH_3I has been theoretically studied in a LEPS PES.Theproduct alignment versus the relative translational energy of the reactantshas been obtained.     

A THEORETICAL STUDY OF THE THERMODYNAMIC AND KINETIC PROPERTIES FOR THE REACTION OF FORMYL CYANIDE DECOMPOSITION

We compute the thermodynamic and the kinetic properties for the reaction:HCOCN→HCH+CO using the statistical theory and the transition-state theory.The equi-librium constants and the rate coefficients of this reaction are also reported here,andthe half lives of formyl cyanide at different temperatures are first estimated in thiswork.     

CHEMISTRY OF DENUDATINE I. THE REACTIONS OF DENUDATINE AND DIACETYLDENUDATINE WITH NBS-HOAc

The reactions of denudatine 1 and diacetyldenudatine 2 with NBS-50% HOAc soln. afforded 4 and 6, respectively, in high yields.Treatment of 6 with (Ac)_2CO-Pyr. gives 7. The structures of 3,6 and 7 were deduced on the basis of spectral and chemical methods.     

DIRECT CONVERSION OF METHANE TO METHANOL——THE EFFECT OF SENSITIZERS ON THE YIELD OF METHANOL AND THE KINETIC STUDY

The partial oxidation of methane to methanol was studied. The effectof various homogeneous "sensitizers" on the oxidation of pure methane was e-valuated at 433℃ and under a pressure of 5.0MPa. It was found that CH_3NO_2was the best one among them. A kinetic study in the presence of CH_3NO_2 wascarried out and the reaction mechanism was discussed.     

KINETIC STUDY OF GAS-PHASE POLYMERIZATION OF PROPENE BY THE INHIBITION METHOD USING CARBON MONOXIDE

The inhibition method using CO to determine the active center concentration C~* in olefin poly-merization and the kinetics of gas-phase polymerization of propene were studied. The reliabilityof the method when used in gas-phase polymerization of propene is proved and the influencing fac-tor of the method is found to be the "repeating inhibition" of CO to the active centers. The C~*, the rate constant k_P and the activation energy were determined from the experimentalresults. We concluded that the C~* decreases with polymerization time and coincides with the decayrate of the polymerization.     

A STUDY OF THE WAVE FUNCTION WITH SYMPLECTIC SYMMETRY~1

By using the linear combination of the AGP(antisymmetrtzed geminat power) and SPG(sequential product of geminats) functions, an attempt has been made to catcutate the ground state of the LiH molecule. The calculated results show that-the AGP or SPG function gives the same ground state result as their linear combination.     

THE REACTION OF O-SILYLATED α-KETOLS WITH TRIMETHYLSILYL CYANIDE

Abstract

The reactions of a series of O-silylated α-ketols with trimethylsilyl cyanide have been investigated. Formation of the expected 0-trimethylsilyl cyanohydrins as major products has been shown to be accompanied by the hitherto unsuspected formation of a disiloxane by a proposed intramolecular S_N2 displacement mechanism. The latter reaction is, surprisingly, independent of the substitution pattern in the silylated ketol. Formation of the side-product, however, increases in all cases with increasing dilution. The α,β-epoxynitrile 9, a second side-product expected, along with the observed disiloxane, by our proposed mechanism was synthesized by an unambiguous route. A control experiment showed the epoxynitrile to be completely destroyed under the usual conditions of reaction with trimethylsilyl cyanide. ¹³C NMR data have been obtained for most of the compounds in this study.     

THE CRYSTALLOGRAPHIC STUDY OF THE COM PLEX OF THE LYS ACTIVE FRAGMENT OF THE MUNG BEAN TRYPSIN INHIBITOR WITH BOVINE TRYPSIN

The Lys fragment of mung bean trypsin inhibitor can combine with bovine trypsin to form a complex at an equal molar ratio. The single cxystals of the complex were obtained by using the micro-still-setting method and the X-ray diffraction extended to 1.8 resolution. Its space group is P2_12_12_1 wlth cell dimensions α=62.9(1), b=63.4(1) and c=69.7(2). There is one complex molecule in a crystallographic asymmetric unit.