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Fusarium sambucinum Fuckel var. minus isolate produced unusual for F. sambucinum Fuckel trichothecene metabolite 4,15-diacetylnivalenol (9 mg/l) in conditions of deep cultivation on Myro medium. This compound was identified by TLC, GLC, HPLC, and 1H NMR spectroscopy. Other trichothecenes, 4-acetylnivalenol (3 mg/l) and nivalenol (1 mg/l), were also found in the culture. The observed feature of the studied isolate is assumed to be due to the presence of an additional gene, which encodes cytochrome P450 oxygenase responsible for the introduction of keto group at C-8 and hydroxyl group at C-7 of the trichothecene structure.

Formylation of photochromic 9′-hydroxy-1,3,3-trimethyl-1,3-dihydrospiro[2H-indole-2,3′-3′H-naphtho[2,1-b][1,4]oxazine] with the paraformaldehyde-MgCl2-Et3N system or by the Reimer-Tiemann reaction proceeds at the ortho-position to the hydroxy group to form 10′-formyl derivative.

The reactions of the quaternary acylammonium salt formed on treatment of3,5-di-tertbutyl-4-hydroxy N,N-dimethylbenzylamine with acetyl chloride, with various organic and inorganic sulfur-containing compounds were studied. The possibility of using this salt for the introduction of a sterically hindered phenol moiety in various sulfur-containing compounds was shown.

The structure of azimexone (3), the product of the reaction of 2-cyanoaziridine with acetone, was confirmed on the basis of1H and13C NMR spectra. The formation of this product is accounted for by the α-aziridinoalkylating action of an intermediate containing a good leaving iminoyloxy group. Similar reactions were observed for 1-chloromethylaziridine and a 1-aziridinylmethylammonium salt (6), but not for 1-methoxymethylaziridine (7) and 1-aziridinemethanol.

Evidence is presented for a synchronous mechanism of the acid-catalyzed 1,2-rearrangement of 2-methoxy-isoxazolidine-2,3-dicarboxylic acid ester with migration of the ester group to the N atom. It was shown that the reaction is suppressed in the presence of an external nucleophile or a reducing agent. The regularities found were used to explain the transformations of bicyclic systems with an -ONO-fragment.

Solvolysis of 1-tosyloxy-Δ2-1,2,3-triazoline-5,5-dicarboxylic acid esters (1) occurs via elimination of N2 and leads predominantly to N-β-hydroxylethyl-O-tosylhydroxylamines (II), whose structure was determined unequivocally by x-ray structural analysis. The mechanism of solvolysis of triazolines (I) is discussed, along with the structural characteristics and stabilization factors of the O-tosylhydroxylamine products (II).

The1H and13C NMR spectral parameters of α-, β-, and y-lewisites1–5 were obtained and a new isomer,cis,trans,trans-γ-lewisite5, was isolated and identified on the basis of chemical shifts, relative intensities of the signals, and the intra-chain (3 J hh ,3 J ch ) and interchain (3 J casch ) coupling constants.

The preferred trans configuration of 1,2-disubstituted aziridines and cis configuration of NH-aziridine-2-carboxylic esters were established by means of the1H and13C NMR spectra and the two-dimensional NOESY and COSY-45 spectra.

1. The mass spectra of the isomeric nitrones, O-ethers, and amides differ in principle, which excludes the possibility of a nitr one-O-ether and nitrone-amide rearrangement under electron impact for compounds of this type. 2. The occurrence of diagnostic fragmentation paths under electron impact for the nitrones, O-ethers, and amides enables these type of valence isomers to be distinguished from their mass spectra.

1. The possibility of obtaining only one ion in the mass spectra was demonstrated in conditions of ionization with UV radiation at atmospheric pressure: the M+ ion for n-alkanes and the MH+ ion for alcohols, ketones, esters, and amines. 2. Ionization with UV radiation at atmospheric pressure permits broadening the linear range by 104–106 times and decreasing the limit of detection ∼102 times in comparison to the existing methods of mass spectral analysis with ionization at atmospheric pressure and by 102–104 and 102 times in comparison to chemical ionization in comparable conditions. 3. The possibility of mass spectrometric analysis of submicrogram quantities of the components of mixtures without preliminary separation was demonstrated on the example of n-alkanes and aromatic hydrocarbons in conditions of ionization with UV radiation.

By using chemical ionization over a wide range of pressures, from 0.01 torr to atmospheric pressure, and also by selecting the reagent gas, different mass spectra of isomers can be obtained, which are suitable for their reliable identification. Under ionization conditions at atmospheric pressure in helium (reagent ions [H(H2O)n]+), peaks of cluster ions [MGH]+ and [2M+1]+ are observed in the spectrum of dimethyl fumarate, which are absent in the case of the cis-isomer. Under the conditions of chemical ionization at a normal pressure (0.4-0.2 torr) of the reagent gases Me3CH, n-C7H16 and at an ionic source temperature of 50°C, a stereospecific fragmentation of dimethyl maleate [MH]+-MeOH is observed, which is absent in the case of the the trans-isomer. In the chemical ionization spectra at reduced pressure of the reagent gases MeOH, EtOH, i-PrOH (0.01 torr), a peak of the cluster ion [MGH]+ is observed for dimethyl fumarate, which is absent in the spectra of the cis-isomer.

1. For the first time a diastereomerically enriched acyclic NH-dialkoxyamine with asymmetric nitrogen atom in the NH group was obtained. 2. By low-temperature PMR spectra the diastereomers of a 1,1-dialkoxyurea with asymmetric amid enitrogen atom were observed.

The reaction of the methyl ester of 1,2-dibromopropionic acid with chiral Β- aminoalcohols under the conditions of the Gabriel-Cromwell reaction gave epimers of methyl 1-(Β-hydroxyalkyl)aziridine-2-carboxylates, which were separated by liquid chromatography. NMR spectroscopy and CD were used to determine the absolute configuration of these products. The relative rate of conversion of epimeric esters of trans-1-(Β-hydroxyalkyl)aziridine-2-carboxylic acids to 1-aza-4- oxabicyclo-[4.1.0]heptan-5-ones is a function of the intramolecular contacts of the reacting OH and CO2Me groups in the lactonization of the cis isomers. The most favorable conformation of the six-membered ring in 1-aza-4-oxabicyclo[4,1,0]heptan-5-ones in solution is a distorted boat.

1. The automatic assembly of dilactones from α,α′-dihydroxyglutaric acids and their derivatives is controlled not only by configuration (from the d, l and not the meso form) but also by conformation and is not realized in the presence of α,α′-substituents having predominantly pseudoequatorial orientation in the corresponding monolactone. Thus, γ-crotonolactone is formed instead of the expected dilactone during the thermolysis of d,l-α,α′-dihydroxyglutaric acid. 2. The diastereomers of α,α′-dibromoglutaric acid and the d,l-forms (in contrast to the meso form) of α,α′-dihydroxyglutaric acid and their esters are conformationally uniform in the case where there is no intramolecular hydrogen bond. 3. The meso forms of the conformationally uniform α,α′-disubstituted glutaric acids differ from the d,l-forms in the nonequivalence of the JCH spin-spin coupling constants with the protons of the CH2 group. 4. Pseudoaxial preference was detected for the CO2H and CO2Me groups in trans-2-hydroxy-4-carboxy-γ-butyrolactone and its methyl ester respectively.

It was shown that the stereospecificity of SSCC3 C,H trans > 3J C,H cis is applicable as a configurational test for di- and trisubstituted alkenes R2E(Y)C=C(X)H with various heteroatomic substituents (E=N, P, S) and activating groups (X=CO2Alk, CN at Y=H, and X=Y=CO2Alk, CN, CF3).

The fragmentation of compounds of the RN(CH2)nCHCOX (n=1–5) and RNCH2C(COX)2 type, where X=OAlk and NH2 and R=H, D, OAlk, and Cl, under electron impact was studied. When n=2–5, the chief fragmentation process is amine fragmentation, and the (M−COX)+ ion peak is the principal peak in the spectra at 30 and 12 eV. The fragmentation of three-membered heterocycles differs radically. The dominant fragmentation for 1-alkylaziridine-2-carboxylic and -2,2-dicarboxylic esters is splitting out of a radical from the ester group. This process is absent when R=H, D, C, and OAlk. Fragmentation with splitting out of the elements of alcohol for the esters and of ammonia for the amines is characteristic in the case of derivatives of 1-alkoxyaziridine-2-carboxylic and-2,2-dicarboxylic acids.

Interconversion of the studied nitrones and corresponding O-ethers of oximes fails to occur during the capture of low-energy electrons, and the mass spectra of the DRCE make it possible to distinguish valence isomers of this type.

The fragmentation of compounds of the RN(CH2)nCHCOX (n=1–5) and RNCH2C(COX)2 type, where X=OAlk and NH2 and R=H, D, OAlk, and Cl, under electron impact was studied. When n=2–5, the chief fragmentation process is amine fragmentation, and the (M−COX)+ ion peak is the principal peak in the spectra at 30 and 12 eV. The fragmentation of three-membered heterocycles differs radically. The dominant fragmentation for 1-alkylaziridine-2-carboxylic and -2,2-dicarboxylic esters is splitting out of a radical from the ester group. This process is absent when R=H, D, C, and OAlk. Fragmentation with splitting out of the elements of alcohol for the esters and of ammonia for the amines is characteristic in the case of derivatives of 1-alkoxyaziridine-2-carboxylic and-2,2-dicarboxylic acids.