Synthesis and cytotoxic activity of a series of diacetylenic compounds related to falcarindiol

The synthesis of a series of diacetylenic compounds related to the natural product falcarindiol has been carried out. Unsymmetrical diacetylenes were prepared by a modification of the Cadiot-Chodkiewicz coupling reaction, while a Glaser coupling was used to prepare symmetrical diacetylenes. These compounds have been tested for in vitro cytotoxic activity against Hep-G2, and H-4-II-E cell lines. Diacetylenes with additional unsaturation at C-1, 2, appended with hydroxyl groups at C-3 and C-8, or with long hydrophobic chains, exhibited IC50 values in the micromolar range.     

Synthesis and characterization of a series of zinc bis[(alkyl)(trimethylsilyl)amide] compounds

A series of 21 secondary (alkyl)(trimethylsilyl)amines HNR(TMS) [R = n-propyl (1), i-propyl (2), n-butyl (3), i-butyl (4), s-butyl (5), tert-butyl (6), c-pentyl (7), n-pentyl (8), i-pentyl (9), l-methylbutyl (10), 2-methylbutyl (11), 1-ethylpropyl (12), 1,2-dimethylpropyl (13), tert-pentyl (14), phenyl (15), c-hexyl (16), n-hexyl (17), N,N-dimethyl-3-aminopropyl (18), benzyl (19), n-heptyl (20), 1,1,3,3-tert-butyl (21); TMS = Si(CH3)3] has been prepared and fully characterized by elemental analyses, multinuclear (1H, 13C, 29Si, 14N) NMR, IR, UV/vis, MS, and boiling point. A new method for determination of boiling points of milligram-size samples, based on DSC (differential scanning calorimetry), is described. Each amine has been converted to the corresponding zinc bis(amide) compound Zn[N(TMS)(R)]2 [R = n-propyl (22), i-propyl (23), n-butyl (24), i-butyl (25), s-butyl (26), tert-butyl (27), c-pentyl (28), n-pentyl (29), i-pentyl (30), 1-methylbutyl (31), 2-methylbutyl (32), 1-ethylpropyl (33), 1,2-dimethylpropyl (34), tert-pentyl (35), phenyl (36), c-hexyl (37), n-hexyl (38), N,N-dimethyl-3-aminopropyl (39), benzyl (40), n-heptyl (41), 1,1,3,3-tert-butyl (42); TMS = Si(CH3)3] and subsequently fully characterized by elemental analyses, multinuclear (1H, 13C, 29Si, 14N) NMR, IR, UV/vis, MS, and TGA. The experimental IR has been compared to the computationally calculated one for compound 27. Observed trends in volatility of the compounds are discussed in the context of the dominant intermolecular forces present in the condensed phase.     

Synthesis of a new series of anti-rhinovirus compounds

The synthesis of a series of 3,6-dichloropyridazine derivatives was described.In vitro experiment,all compounds exhibited ananti-rhinovirus activity,and one of the compounds 6g showed the comparable activity as our lead compound pirodavir.     

Synthesis and characterisation of severely hindered P-OR compounds

P-Cl substrates were converted into their P-OR analogues from hindered alcohols using an amine base. Where the system was severely hindered, more forcing conditions were required that necessitated the presence of a metal alkoxide nucleophile before successful reactions were observed. In some instances, the products were thermally unstable and reverted to alkenes by elimination reactions, while others were sensitive to moisture. Here, hydrolysis products prevailed if moisture was not rigorously excluded. Details are presented to obtain the P(III) and P(V) esters, diesters and half esters.     

Synthesis and characterisation of luminescent fluorinated organoboron compounds

The reaction of 8-hydroxyquinoline (HQ) with B(C(6)F(5))(3) leads to the formation of the zwitterionic compound (C(6)F(5))(3)BQH (1), involving a proton migration from O to N. Compound 1 can be converted thermally to (C(6)F(5))(2)BQ (2), which can also be prepared from (C(6)F(5))(2)BCl and HQ. The reaction of HQ with (C(6)F(5))B(OC(6)F(5))(2) generates initially (C(6)F(5))(OC(6)F(5))BQ (3), which easily hydrolyses to give the diboron compound ((C(6)F(5))BQ)(2)O (4). Compounds 1, 2 and 4 have been fully characterised, including X-ray analysis. The spectroscopic properties of these compounds, including photoluminescence (PL) have been investigated and compared with the non-fluorinated luminescent boron compound (C(6)H(5))(2)BQ and also with AlQ(3). The changes in luminescent behaviour upon fluorination of these boron quinolinate compounds have been rationalised using computational studies.     

Synthesis of natural phytosteroids of the 6-ketostigmastane series and compounds related to them

Preparative methods of synthesizing a number of natural 6-ketosteroids and 6-alcohols related to them from -sitosterol have been developed.Institute of Bioorganic Chemistry, Academy of Sciences of the Belorussian SSR, Minsk. Translated from Khimiya Prirodnykh Soedinenii, No. 6, pp. 771–776, November–December, 1990.     

Synthesis of natural phytosteroids of the 6-ketostigmastane series and compounds related to them

Preparative methods of synthesizing a number of natural 6-ketosteroids and 6-alcohols related to them from β-sitosterol have been developed.     

Synthesis and fluorescence of a series of multichromophoric acenaphthenyl compounds

A novel free radical trapping reaction based on a stepwise radical reversible addition-fragmentation mechanism has been utilized to synthesize a series of acenaphthenyl dimers and trimers. The synthetic procedure involves the reaction of acenaphthylene with dithiobenzoate compounds (S=C(Ph)-SR) in the presence of a free radical initiator followed by reduction of the dithiobenzoyl end group with tributyltin hydride. Stereoisomers of the compounds have been isolated and their structures determined by proton NMR and X-ray crystallography. The solution fluorescence of the compounds has been characterized to reveal the requirements for intramolecular excimer (excited-state dimer) formation. Only in compounds containing identical stereochemical arrangements of adjacent acenaphthenyl groups is excimer fluorescence observed following photoexcitation.     

Synthesis of dl-guinesines and related compounds

Guinesines A, B and C were synthesized starting from 1,3-bis(benzylthio)-2-propanone and N-methyl-2,2-diethoxypyrrolidine.     

Synthesis of primary,secondary, and tertiary alkoxy alcohols of the enyne series

Summary By reacting ethynylvinyl ethers with aldehydes, ketones and ethylene oxide, a method was developed for the synthesis of primary, secondary, and tertiary alkoxy enyne alcohols of diverse structure, the hydration of which leads to the formation of alkoxy ketols.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 2, pp. 359–362, February, 1965     

Synthesis of santonin related compounds

(±)-1-Nordesmotroposantonin ( 2 ), a thermolysis product of santonin, and its isomer, α-(1,2,3,4-tetrahydro-1,7-dihydroxy-α,6-dimethyl-2-naphthalene)acetic acid γ-lactone ( 3 ) were synthesized from 4-(4-methoxy-3-ethylphenyl)butanoic acid.     

Synthesis of shikalkin and certain related compounds

A successful total synthesis of a biologically active pigment from plants of the Boraginaceae family was carried out with naphthazarine as the starting material, and using the 1,4,5,8-tetramethoxynaphthalene, the corresponding 2-vinyl derivative and its epoxide or a cyclopropane adduct with diazoacetic ester at the key stages. In the course of developing the scheme of the synthesis of shikalkin, its three analogs were obtained, differing in the nature of the monoterpenoid side chain.For preliminary report, see [1].Pacific Ocean Institute of Bioorganic Chemistry, Far East Branch of the Russian Academy of Sciences, 690022 Vladivostok. N. D. Zelinskii Institute of Organic Chemistry, Russian Academy of Sciences, 117913 Moscow. Translated from Izvestiya Akademii Nauk, Seriya Khimicheskaya, No. 8, pp. 1901–1910, August, 1992.     

Synthesis of glycosyl phosphonates and related compounds

The synthesis of glycosylphosphonates, isopolar, nonisosteric analogues of glycosylphosphates, from halonitro ethers, glycosyl acetates, or glycosyl trichloroacetimidates is reviewed. A new approach to phosphonate analogues of myo-inositol trisphosphate ( 50 ) is described. Based on a hypothetical reaction mechanism for the formation of thioethers from a glyoxalase I inhibitor, an advanced intermediate 59 for the synthesis of diphosphonate–phosphate analogues of 50 is obtained by an addition–elimination–addition sequence from 54 . Finally, glucosylphosphines, characterized as the corresponding phosphine oxides 61 and 62 have been prepared from the glycosylidene diazirine 60 , a precursor of the tetra-O-benzylglucopyranosylidene carbene. The phosphine oxides 61 and 62 were also obtained by reaction of the glycosyl acetate 18 with methyl diphenylphosphinite.