Synthesis of 6,13-Dihydroxyimino-5,12-Dimethyl- 7,14-Dioxo-1,4,8,11-Tetraazacyclotetradeca-4,11-Diene

6,13-Dihydroxyimino-5,12-dimethyl-7,14-dioxo-1,4,8,11-tetraazacyclotetradeca-4,11-diene 2 was prepared by condensation of ethyl α-oximinoacetoacetate with ethylenediamine in tetrahydrofuran at room temperature. Reduction of 2 gave the corresponding 6,13-dihydroxyimino-5,12-dimethyl-7,14-dioxo-1,4,8,11-tetraazacyclotetradecane 3 . Acylation of 2 afforded 6,13-bis(O-acetoxyimino)-5,12-dimethyl-7,14-dioxo-1,4,8,1 l-tetraazacyclotetradeca-4,11-diene 4 . The structures of 2 , 3 and 4 were determined by IR, NMR and mass spectroscopy.     

Highly efficient biocatalytic resolution of cis- and trans-3-aminoindan-1-ol: syntheses of enantiopure orthogonally protected cis- and trans-indane-1,3-diamine

The efficient chemoenzymatic synthesis of enantiopure 1,3-difunctionalized indane derivatives has been achieved. The corresponding cis and trans N-protected amino alcohols were successfully resolved by acetylation using lipase B, which is a biocatalyst isolated from Candida antarctica. All the possible isomers were obtained in very good chemical yields and ee values (>99 %). The utility of these compounds was subsequently shown by the preparation of orthogonally protected cis- and trans-indane-1,3-diamine using a Mitsunobu reaction. Both enantiomers of the trans isomer and a desymmetrized cis diastereomer were prepared in enantiopure form. Complete inversion of configuration during the Mitsunobu reaction was demonstrated by a combination of NMR techniques and molecular modeling. The utility and versatility of the strategy was also demonstrated by the selective deprotection of each nitrogen atom under mild reaction conditions.     

The synthesis and structure of trans-di(cyano-κ)-(trans-6,13-dimethyl-6,13-bis(propionylamido)-1,4,8,11-tetraazacyclotetradecane-κ)cobalt(III) perchlorate dihydrate

trans-Di(cyano-κ¹)-(trans-6,13-dimethyl-6,13-bis(propionylamido)-1,4,8,11-tetraazacyclotetradecane-κ⁴)cobalt(III) perchlorate dihydrate, trans-[Co(C₁₈H₃₈N₆O₂)(CN)₂)]ClO₄ · 2H₂O, is formed by reaction of trans-[Co(diam)(CN)₂]ClO₄ · 2H₂O (diam = trans-6,13-diamino-6,13-dimethyl-1,4,8,11-tetraazacyclotetradecane) with propionic anhydride in DMF. The centrosymmetrical cation has the azamacrocycle in planar coordination by the four secondary amine nitrogen atoms of the azamacrocycle, with Co–N = 1.979(2) and 1.968(2) Å and with trans cyano groups with Co–C = 1.920(2) Å. The propionylamido substituents are axially oriented, with the terminal methyl group disordered over two sites.     

5,12-二苯基-7,14-二甲基-1,4,8,11-四氮杂环十四烷-N,N″-二乙酸及其镧系配合物的合成和表征

多氮杂大环的配位化学一直是人们感兴趣的领域。近年来,人们努力把支链配位基团引入大环中,以便得到同时具有相对刚性和动力学稳定性的大环结构单元和具有相对柔性和动力学活性的开链结构单元的新型配体。我们曾通过简单的立体化学选择合成得到一系列部分N-乙酸取代六甲基四氮杂大环。本文报道新的大环配体c-meso-meso-5,12-二苯基-7,14-二甲基-1,4,8,11-四氮杂环十四烷-N,N″-二乙酸(H_2L~3及其镧系配合物的合成和表征。     

Convenient Preparation of Chiral trans-9,10-Dihydrophenanthrene-9,10-diamine

Chiral trans-9,10-dihydrophenanthrene-9,10-diamine was conveniently prepared from biphenyl-2,2′-dialdehyde using intramolecular imino pinacol coupling and oxidative cleavage of aminoalcohol as key steps.     

The synthesis of cis- and trans-1,2-dibromocyclopropane

A preparative route to cis- and trans-1,2-dibromocyclopropane ($\text{1}$) was developed via the Hunsdiecker reaction of silver cyclopropane-1,2-dicarboxylate ($\text{2}$). Cis- and trans-$\text{2}$ gave the same ratio of cis- and trans-$\text{1}$ (1:3.2). The mechanism of this reaction is briefly discussed.     

Conformational equilibrium of cis- and trans-3-chloromethylcyclohexanes

Conclusions It has thus been shown both by calculations of the van der Waals interactions and from the molar extinction coefficients of the valence vibration bands of the equatorial C–Cl bonds that cis-3-CMCH consists of the conformer having the CH₃ group and the chlorine atom oriented equatorially, in agreement with the usual assumptions as to the conformations of cis-1,3-disubstituted cyclohexanes.For trans-3-CMCH the calculated E(_e–) values (+150 and +650 cal/mole) are somewhat lower than the experimental value (+870 cal/mole), but all the same there is quite reasonable agreement between them within the limits of the usual errors. In this case the equatorial is preferentially occupied by the CH₃ group, the chlorine atom being axially oriented.Institute for Petrochemical Processes, Academy of Sciences of the Azerbaidjanian SSR, Sumgaitskii Branch. Translated from Zhurnal Strukturnoi Khimii. Vol. 15, No. 1, pp. 148–151. January–February, 1974.     

Synthesis of polysubstituted cis- and trans-2,5-dihydronicotinonitriles

A method for synthesis of cis- and trans- polysubstituted 2,5-dihydronicotinonitriles III from N,N-disubstituted arylacetamidines I and ylidenemalononitriles II at room temperature in THF is reported.     

Diene condensation of cis- and trans-2-cyclododecenone

Conclusions In the diene condensation of the cis- and trans-2-cyclododecenones with butadiene only the transisomer reacts, with the formation of trans-bicyclo [10. 4. 0]-14(15)-hexadecen-2-one, which when treated with t-C₄H₃OK is isomerized completely to cis-bicyclo[10. 4. 0]-14(15)-hexadecen-2-one.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 9, pp. 2157–2159, September, 1973.     

Trivalent Copper Complexes with 1,4,8,11-Tetramethyl-1,4,8,11-tetraazacyclotetradecane in Aqueous Solutions. A Pulse Radiolysis and Electrochemical Study

The mechanisms and kinetics of the formation and decomposition of the complexesCu^IIIL_aq and [LCu^IIIN₃]²⁺ are reportedand discussed.     

顺式-和反式-2,5-二取代四氢呋喃的立体选择性合成

内酯与有机锂试剂发生亲核加成反应,再在酸催化下用NaBH3CN还原,反应的立体选择性可能是由氢负离子在中间体氧鎓离子位阻最小的一侧进攻所引起.所得的三环化合物经热分解和加氢反应,制备顺式和反式-2,5-二取代四氢呋喃.     

Synthesis of enantiopure cis- and trans-2,3-disubstituted piperidines

The synthesis of enantiopure cis- and trans-2,3-disubstituted piperidines 4 is described. The key step of the synthesis involves the stereoselective reduction of chiral nonracemic lactams 2 by using BH3.Me2S. A rationalization of the stereoselectivity is presented.     

CH-stretching overtone spectra of cis- and trans-1,3-pentadiene

The room-temperature vapor-phase overtone spectra of cis- and trans-1,3-pentadiene (piperylene) have been recorded in the 5000-17500 cm(-1) region with the use of conventional and intracavity laser photoacoustic spectroscopy. The presence of five nonequivalent olefinic CH bonds and one methyl group in each molecule complicates assignment of the spectra. We have used a harmonically coupled anharmonic oscillator local mode model with one oscillator for each of the nonequivalent CH bonds to calculate the CH-stretching overtone spectra and thus facilitate assignment of the spectra. Our calculated spectra are in good agreement with the observed spectra. The observed high overtone spectra are distinctively different despite the similarity of the two molecules and the numerous and broad transitions.     

Dehydrohalogenations of cis- and trans-1-bromo-2-flourocyclohexanes

Reactions of both diastereomeric vicinal bromofluorocyclohexanes with sodamide, sodium methoxide, potassium tert-butoxide, and triethylamine were studied. cis-1-Bromo-2-fluorocyclohexane eliminated almost exclusively hydrogen bromide giving mainly 1-fluorocyclohexene and a small amount of 3- fluorocyclohexene. trans-1-Bromo-2-fluorocyclohexane eliminated preferentially hydrogen fluoride on treatment with sodamide. Potassium tert- butoxide eliminated hydrogen bromide and yielded 3-fluorocyclohexene and a small amount of 1,3-cyclohexadiene, whereas sodium methoxide converted trans-1-bromo-2-fluorocyclohexane to 3-fluorocyclohexene and 3-methoxycyclohexene. Possible mechanisms and stereochemistry of the preferential elimination of hydrogen fluoride are discussed and new interpretations are offered.