The results were consistent with reaction via a nitrile ylide intermediate, the reaction 213 '14 '15 216 C-G. Compound 72 arises by further photorearrangement of the oxetan 71 , and the products can be accommodated as shown in Scheme 5. However, by 1967 the whole spectrum of chemistry could no longer be contained within one volume and the series Specialist Periodical Reports was born. The presence of chlorine greatly increases the hydrolytic reactivity of aliphatic epoxides, the rate for trichloroethene oxide being 2 x lo4 times faster than that for ethene oxide itself. The key intermediate in the reaction is thought to be the complex 177. Wagai, Tetrahedron, 1978, 34, 3445.
Photosensitized epoxidation has received considerable attention over the past few years. Aziridines are known to react with alkylidenephosphoranes, yielding 3pyrrolines. It has been reported15' that N-alkoxyaziridines react with nitriles in the presence of boron trifluoride etherate, thus affording a new route to 2imidazolines. Methods for the synthesis of episulphoxides using metaperiodate or perbenzoic acids in dichloromethane, the thermal decomposition of episulphoxides and the trapping of sulphur monoxide with conjugated olefins, the addition reactions of episulphoxides with thioketones, and the thermal decomposition of episulphoxides substituted with alkyl groups have been re~iewed? Sodium isoquinolinyl- 1-thiolate condenses with ethyl bromocyanoacetate to give the salt 222 286 and with ethyl bromomalonate to give the meso-ionic compound 223. Three-membered Ring Systems 41 l , l - d i ~ x i d eDiphenylthiiren.
In some cases, thienyl-l,2,4-triazines 132 were obtained. Alkylations of isoquinoline Reissert compounds, often a key step in the synthesis of benzyl-isoquinolines and aporphine alkaloids, using sodium Reagent: i, I, Scheme 39 145 '41 14' '41 C. You would be happy that how much you could save by doing book price comparison. Leslie Crombie was born in York on 10 June 1923, the second eldest, and only boy, of Walter Crombie and Gladys née Clarkson. D e Bertorello, A n.
Interest in a-alkylation of butyrolactones continues and a number of routes have been reported,202usually directed towards the synthesis of or-methylenebutyrolactones. Hall and H ~ r s f a lhave l ~ ~ applied the dipole moments method to the determination of the conformational properties of lY3-dinitrohexahydropyrimidines. D e Micheli, Heterocycles, 1979,12,5. Treatment of the same acetal with N-bromosuccinimide in water followed by treatment with B. Quantitative investigations of nucleophilic aromatic substitution in the thiophen field are continuing. The isoquinuclidienones derived from maleic anhydride yield pyridones by elimination of an ethylene unit.
Thermal cycliation of the cis-crotylamide 162 occurs at 230-280 O C to yield 1-acylpyrrolidines 163. Several detailed studies this year support such a mechanism, and the general consensus of opinion can be summarized in Scheme 6. It has been shown that thiophen itself undergoes the Diels-Alder reaction at high pressure. The proportions of the cyclopeptide products produced in these novel cyclooligomerisations varied when the cyclisations were carried out in the presence of various metal ions, e. Adducts of pyridynes with furans, e g. With optically active aziridinones obtained by dehydrohalogenation of a-halogeno-amides, abstraction of halide occurs from the asymmetric carbon atom, and therefore partial racemization is possible.
Surprisingly though, there exists to our knowledge no single periodical review alerting the reader on an annual basis to important developments of the subject. It was converted into the 2-bromo-derivative, which was used for the synthesis of other derivatives. The reaction of benzylideneanilineor benzylidine-p-toluidinewith hydroxyamino-O-sulphonic acid in the presence of aniline or p-toluidine does not yield the expected diaziridines but benzaldehyde phenyl- or p-tolyl-hydrazones. Sternson, Tetrahedron Letters, 1973, 1315. Ketones undergo reaction with alkyl and aryl a ~ i d e s in l ~the ~ presence of base, forming A2-1,2,3-triazolines. Heterocyclic Chemistry 96 5-Substituted thienylacetic acids have been investigated for inhibition of platelet aggregation. Heterocyclic Chemistry Vlll Reactions Photochemical and Thermal Cyclization to Five- and Six-membered Heterocyclic Systems With Metal Carbonyls 35 35 36 37 5 Thiirans Preparation Reactions Chemistry of Thiiranium Ions 38 38 39 39 6 Thiirens 40 7 Diaziridines 41 8 Diazirines 42 9 Oxaziridines 42 10 Thiazirines Chapter 2 Four-membered Ring Systems By R.
The reaction of Wittig-type reagents with oxirans to form cyclopropanecarboxylic acid derivatives has been well documented. Saturated Heterocyclic Chemistry 86 460 t- Scheme 30 to arise by a Michael-type addition of the N-alkylated nitrogen of the diaziridine to the alkyne linkage Scheme 30. Montei1-0~~~ has published details of the total synthesis of cucurbitine 183 , an uncommon amino-acid with plant-growth regulatory properties. The products may be isolated in pure form and it has been possible specifically to locate an l 8 0 label in the peroxide or ether linkages. The transisomers 41a and b preferentially adopt a diequatorial conformation. In related photorearrangements 9-azabarbaraIanesG7 and azabullvaleness8were obtained Scheme 10.
The observed product was the 3-arylcarbamoyl lactim ether 191 ; this may be rationalized in terms of the initial isomerization of 190 to the enamine 192. A proposed mechanism, which is supported by lo' '06 lo' lo' lo9 'lo '11 S. Nitrile ylides may be trapped with forming 3-oxazolines, although care should be exercised, since if the nitrile ylide is generated photochemically secondary transformations of the oxazolines may The mild, non-photochemical method of preparing nitrile ylides by the dehydrohalogenation of benzimidoyl chlorides154with triethylamine is clearly a method of choice and fair yields of cycloadducts may be obtained. Hydrogenation of the + -isomer yields a mixture of erythro-2-ethyl-3-methylsuccinimide and - -threu-2S-ethyl-3S-methylsuccinimide. The reaction of nitrile imines with cyclo-octatetraene gives unexcept ional p r 0 d ~ c t s.
Turro, Annalen, 1973, 1984; N. Also new is the synthesis of 3-substituted isoquinolines from a-acyl-o-toluonitriles, as outlined in Scheme 38. The Darzens condensation of aldehydes and ketones may be one of the most convenient and common procedures for the one-step synthesis of 2,3-epoxyalkanoates,but little has been reported on the reactions of a-halogeno-aldehydes under such conditions. The latter was converted into a cyclic tetramer with disulphide bonds, the structure of which was determined by X-ray cry~tallography. ~~~ The reaction of tetramethyl-l,2-dioxetan with triphenylphosphine gives the phosphorane 235 , which decomposes above 55 'C to give phosphine oxide and tet ramethylethylene oxide.