bluuebunny/crossref_metadata_2025_split huggingface dataset:
Kinetic Studies of Fast Equilibrium by Means of High-performance Liquid Chromatography. III. Ternary Complex Formation between Ni(II) Diethyldithiocarbamate and Other Unlike Ni(II) Chelates
Authors: Moriyasu Masataka , Hashimoto Yohei 
Published: July 2006

Abstract
The labile ternary complex formation (MA2+MB2\ightleftharpoons2MAB with K=[MAB]2/([MA2][MB2])) between Ni(II) diethyldithiocarbamate(MA2) and other several Ni(II) chelates(MB2) was investigated by high-performance liquid chromatography; two solutions of MA2 and MB2 were mixed and equilibrated. The tendency to form a ternary complex is summarized as follows: (1) no ternary complex formation takes place (B=dimethylglyoxime and 1-(2-pyridylazo)-2-naphthol), for which high structural stability of binary complex MB2 is responsible; (2) the ternary complex formation is controlled statistically (K=4.0), suggesting the absence of any factor to stabilize or unstabilize the ternary complex (B=N,N-disubstituted dithiocarbamates and N-monosubstituted dithiocarbamates); (3) the ternary complex formation is favored (K&gt;4.0) (B=xanthates); and (4) all initial binary complexes are converted into a very stable species which is possibly a ternary complex (B=dithizone). Kinetic characteristics of these ternary complex formations are examined.
Reactions of Bis(β-diketonato)palladium(II) and -platinum(II) with Tertiary Phosphines
Authors: Okeya Seichi , Nakamura Yukio , Kawaguchi Shinichi 
Published: July 2006

Abstract
Bis(β-diketonato)palladium(II) and -platinum(II) readily react with tertiary phosphines (L) to afford [M(β-dik)(β-dik-O)L], [M(β-dik)L2](β-dik), [ML4](β-dik)2, [M(β-dik-O)2L2], and [M(β-dik)(β-dik-C)L] complexes, which were characterized mainly by infrared and 1H and 13C NMR spectroscopy. Factors influencing the relative stability of each bonding mode of β-diketonate anions were investigated.
Synergistic Extraction of Vanadium(V, IV) with Dithizone
Authors: Akaiwa Hideo , Kawamoto Hiroshi , Hiyamuta Etsuo 
Published: July 2006

Abstract
By employing the synergistic extraction technique, vanadium (V,IV) has been found to form the primary dithizonate in the presence of a synergist. The extraction of the element proceeds according to the following equations.
VO2++H2dz,org+TBPOorg\ightleftharpoonsVO2(Hdz)(TBPO)Org+H+,
and
VOOH++H2dz,org\ightleftharpoonsTOPOorg\ightleftharpoonsVOOH(Hdz)(TOPO)org+H+,
where H2dz, TBPO, and TOPO denote dithizone, tributylphosphine oxide and trioctylphosphine oxide, respectively, and the subscript org indicates the benzene phase. The resulting adduct VO2(Hdz)(TBPO) has an absorption maximum at 503 nm and is stable for at least 1 h. However, the red color of VOOH(Hdz)(TOPO) in benzene fades away during the standing time, probably due to the dimerization of the initially extracted monomeric species.
Platinum Chloride–Diphosphine–Tin(II) Halide Systems as Active and Selective Hydroformylation Catalysts
Authors: Hayashi Teruyuki , Kawabata Yasuziro , Isoyama Toyoshiro , Ogata Ikuei 
Published: July 2006

Abstract
The hydroformylation of 1-alkenes was efficiently catalyzed by PtCl2–diphosphine–SnX2 systems whose diphosphines were 1,4-bis(diphenylphosphino)butane derivatives with rigid ring skeletons. The effects of the structure of diphosphines, the P/Pt atomic ratio, the sort of tin(II) halide or solvent, the reaction variables, and the structure of olefins on the relative rate and the product distribution were investigated. A higher reaction rate than when using HRh(CO)(PPh3)3, and a linearity of aldehydes up to 99%, were attained. The coordination structure of the effective diphosphines as well as the reasons for the rate enhancement and for the excellent selectivity were discussed.
The Rhodium Complex-catalyzed Synthesis of Quinolines from Aminoarenes and Aliphatic Aldehydes
Authors: Watanabe Yoshihisa , Shim Sang Chul , Mitsudo Take-aki 
Published: July 2006

Abstract
A variety of aminoarenes react with aliphatic aldehydes in the presence of a catalytic amount of a rhodium complex and an excess amount of the corresponding nitroarenes at 180 °C to give 2-alkyl- and 2,3-dialkyl-substituted quinolines in excellent yields. Among the rhodium complexes examined, [Rh(norbornadiene)Cl]2 exhibits the highest activity as a catalyst. Thus, 2-methyl-, 2-ethyl-3-methyl-, 2-propyl-3-ethyl-, and 2-butyl-3-propylquinoline derivatives are readily obtained from aminoarenes and ethanal, propanal, butanal, and pent-anal respectively.
Syntheses and Properties of α-Ethyl-substituted Bisdehydro[13]annulenone and Its Benzo-annelated Derivatives
Authors: Ojima J\={u}ro , Juni Yasushi , Yoneyama Yoshiharu , Wada Kazuyo , Murosawa Yoshiko 
Published: July 2006

Abstract
2-Ethyl-5,10-dimethyl-, 13-ethyl-10-methyl-4,5-benzo-, 2-ethyl-10-methyl-4,5-benzo-, and 2-ethyl-4,5:10,11-dibenzo-6,8-bisdehydro[13]annulenone were synthesized. Influence of α-ethyl substitution upon the skeleton of the bisdehydro[13]annulenone ring system is discussed on the basis of 1H NMR and UV spectra of these an-nulenones and their corresponding α-methyl-substituted derivatives.
Low-temperature Reflection Spectra of the Single Crystals of TCNQ Complex Salts
Authors: Yakushi Kyuya , Iguchi Masaaki , Katagiri Gen , Kusaka Takahisa , Ohta Toshiaki , Kuroda Haruo 
Published: July 2006

Abstract
The visible and near-infrared reflection spectra were measured, at temperatures in the range of 27–300 K, on the single crystals of (N-ethyl-1,10-phenanthrolinium)(TCNQ)2, (methyltriphenylphosphonium)(TCNQ)2 and Cs2(TCNQ)3. We found that the dispersion observed at about (10–11)×103 cm−1 in the reflection spectra of the former two salts is due to the local excitation associated with the lowest π-π transition of (TCNQ)−. A new dispersion attributable to intermolecular charge transfer was found to appear at (7–8)×103 cm−1 in the spectrum of (methyltriphenylphosphonium)(TCNQ)2, at low temperature. In the case of Cs2(TCNQ)3, the low-temperature spectrum showed that there are two dispersions in the range of (8–14)×103 cm−1, one of which being attributable to the charge transfer between (TCNQ)− ions and the other to the local excitation associated with (TCNQ)−. We propose a new interpretation for the spectra of TCNQ complex salts on the basis of these new experimental data.
Reduction by a Model of NAD(P)H. 33. Steric and Electronic Effects on Asymmetric Reduction of 2-Acylpyridines
Authors: Ohno Atsuyoshi , Nakai Jun-ichi , Nakamura Kaoru , Goto Takehiko , Oka Shinzaburo 
Published: July 2006

Abstract
Series of alkyl and fluorinated alkyl 2-pyridinyl ketones have been reduced by a chiral NAD(P)H-model (Me2PNPH) in the presence of magnesium ion in acetonitrile. Optical yield decreases in the order of substituent: CH3&gt;C2H5&gt;C(CH3)3&gt;CH(CH3)2 and CH3&gt;CH2F&gt;CHF2&gt;CF3. The results have been interpreted in terms of conformation of the substrates for alkyl 2-pyridinyl ketones and of electronic competitional effect between two substituents for fluorinated alkyl 2-pyridinyl ketones. Magnesium ion freezes intermolecular arrangement at the transition state of the reduction.
Reduction by a Model of NAD(P)H. 34. Substituent Effect on Asymmetric Reduction of Trifluoroacetophenones
Authors: Ohno Atsuyoshi , Nakai Jun-ichi , Nakamura Kaoru , Goto Takehiko , Oka Shinzaburo 
Published: July 2006

Abstract
Substituted and unsubstituted α,α,α-trifluoroacetophenones were reduced by a chiral NAD(P)H-model (RR-Me2PNPH). Both electron-releasing and -withdrawing substituents give better optical yields than unsubstitued compound. The result has been interpreted in terms of three-step mechanism which involves initial electron-transfer process.
Kinetic Studies on Intramolecular Excimer Formation in Dinaphthylalkanes
Authors: Ito Shinzaburo , Yamamoto Masahide , Nishijima Yasunori 
Published: July 2006

Abstract
Various dinaphthylalkanes in which two naphthyl groups are separated by three carbon atoms were prepared, and intramolecular excimer formation was investigated. All rate constants in Förster’s kinetics were determined by the steady state and time-resolved fluorescence measurements. A large difference in the association rate constant was observed with variation of molecular structure. The results suggest that intramolecular excimer formation is directly controlled by the rotational relaxation processes of the molecules from their neighboring conformations to the excimer conformation. A large formation rate (7.9×108 s−1 at 25 °C) was observed for meso-2,4-dinaphthylpentane, the rate for the racemo isomer being found to be one tenth of that for the meso isomer. This indicates that the isotactic sequence in vinyl aromatic polymers plays an important role in the intramolecular excimer formation.
Studies of Matrix Effects on 57Co-Labelled Tris(β-diketonato)cobalt(III) by Means of Mössbauer Spectroscopy
Authors: Sakai Yoichi , Endo Kazutoyo , Sano Hirotoshi 
Published: July 2006

Abstract
The emission Mössbauer spectra at 78 K of 57Co-labelled Co(dbm)3 (dbm=dibenzoylmethanato) dispersed in 2-methyltetrahydrofuran, or of 57Co-labelled Co(acac)3 (acac=acetylacetonato) dispersed in a mixed medium of oxalic acid and polystyrene, give no appreciable magnetic hyperfine structure (hfs), while those of 57Co-labelled Co(acac)3 dispersed in polystyrene and 57Co-labelled crystalline Co(dbm)3 give a magnetic hfs. The results indicate that the local radiolysis of EC-decay involves not only the labelled species itself, but also the neighbouring host matrix.
Some Aspects of the Solvent Extraction-spectrophotometric Determination of Copper Dithiocarbamate Complex in Strongly Acidic Media
Authors: Takada Takeo , Okabe Yukio , Nakano Kunio 
Published: July 2006

Abstract
The time stability of the extracted complexes in isobutyl methyl ketone depends on the pH of the washing solution of the extract and on the stability of the metal complex. The extract is stable to concentrated acid when the organic extract is separated rapidly and washed with water. Copper (II) tetramethylenedithiocarbamate is quantitatively extracted from 1–6 and 1–2 mol dm−3 hydrochloric and nitric acid media respectively.
The Preparation and Properties of Cobalt(III) Phosphine Complexes Containing Nitrite and Acetylacetonate Ions
Authors: Hayakawa Satoru , Nishikawa Hiroaki , Kashiwabara Kazuo , Shibata Muraji 
Published: July 2006

Abstract
Two complexes, [Co(NO2)(acac)2(P)](acac=acetylacetonate ion, P=PBu3, PBu2Ph, PMe2Ph, and PMePh2) and [Co(NO2)2(acac)(PMe2Ph)2], were prepared by a reaction between Na[Co(NO2)2(acac)2] and phosphines. The geometrical structures were determined on the basis of the 1H NMR, electronic, and IR spectra. A cis(NO2,P) configuration was assigned to [Co(NO2)(acac)2(P)], and a trans(P,P) configuration, to [Co(NO2)2(acac)(P)2].
Theory of Molecular Deformation Due to the Vibronic Interaction between Two Closely-spaced Electronic Levels. I
Authors: Kimura Minoru , Nishikawa Kiyoshi , Aono Shigeyuki 
Published: July 2006

Abstract
An theoretical investigation was made of the vibronic interaction between two electronic levels which are degenerate or nearly degenerate. Within the mean field approximation we derive a simplified effective Hamiltonian to analyze the problem of bond distortion of a molecule; the effective Hamiltonian is diagonalized by a linear canonical transformation of electronic operators. Thermodynamic arguments predict a possibility for appearance of a distorted phase below a characteristic temperature. The distorted phase is realized under a sufficiently strong coupling condition in a non-degenerate case, but under an arbitrarily small coupling condition in a degenerate case. The shift of electronic spectrum, the stabilization energy of the distortion, and thermodynamic quantities are expressed in terms of the parameters associated with the Hamiltonian. Change in electromagnetic properties due to the distortion is discussed. Magnitudes of the bond distortion and energy stabilization in the ground state are numerically estimated for cyclobutadiene, with results in good agreement with literature values.
Redetermination of the Crystal Structure and the Electrical Resistivity of Rb–TCNQ-II
Authors: Kobayashi Hayao 
Published: July 2006

Abstract
The crystal structure of Rb–TCNQ-II was redetermined. The interplanar distance between the neighbouring TCNQ’s is 3.25 Å, which is almost equal to those of highly conducting TCNQ salts. The electrical resistivity and the structure of the TCNQ, columns suggest that the complete charge transfer in Rb–TCNQ-II makes this crystal low-conducting. The activation energy of the electrical conduction indicates that the dimerization gap appears below the monomer-dimer transition temperature. The temperature dependence of the electrical resistivities of Rb2TCNQ3 is also described.
Catalytic Activity of Highly Dispersed Palladium. II. X-Ray Photoelectron Spectroscopic and Thermal Desorption Studies of the Effects of ZrO2 Added to α-Alumina-supported Palladium
Authors: Lee Bu Yong , Inoue Yasunobu , Yasumori Iwao 
Published: July 2006

Abstract
The effects of ZrO2 upon the catalytic properties of α-alumina-supported palladium for the hydrogenation of gaseous cyclohexene were studied by means of detailed kinetic analysis, thermal desorption (TD), and X-ray photoelectron spectroscopy (XPS). The catalysts, with ZrO2 added in amounts ranging from 0.1 to 45 in Zr/Pd ratio, were characterized by CO chemisorption and X-ray diffraction. The addition of ZrO2 at the Zr/Pd ratio of 0.5 enhanced the turn-over frequency of the hydrogenation by a factor of 7 and changed the hydrogen order of the reaction from 1.0 to 0.75 and the cyclohexene order from 0 to 0.6. The reaction with D2 exhibited deuteriumdistribution patterns similar to those for the reaction on the ZrO2-supported Pd catalysts. The hydrogenation pathway on the ZrO2-added catalyst was described by an associative mechanism in which the slow step was a surface reaction between a cyclohexyl radical and a hydrogen atom. In the thermal desorption spectra, the addition of ZrO2 caused a broadening of the adsorbed hydrogen peak as well as a shift of the dissolved hydrogen peak toward a lower temperature. The desorption of cyclohexene from Pd/α-Al2O3 catalysts underwent a disproportionation to produce benzene around 318 K and cyclohexane at 368 K, whereas the latter peak shifted by 70 K to the lowertemperature side upon the addition of ZrO2. The XPS study showed that the presence of ZrO2 provided Pd metal atoms in a negatively-charged state. The support effect was discussed on the basis of the interaction between Pd metal atoms and ZrO2 oxide.
Mössbauer Spectroscopic Study of Potassium Borosilicate Glasses at Low Temperatures
Authors: Nishida Tetsuaki , Hirai Toshiharu , Takashima Yoshimasa 
Published: July 2006

Abstract
The Mössbauer technique at the liquid nitrogen temperature (78 K) was applied to the estimation of nonbridging oxygens in FeO4, BO4, and SiO4 units in potassium borosilicate glasses. Mössbauer spectra consist of a quadrupole doublet and a hyperfine structure due to Fe3+ ions with tetrahedral symmetry. The hyperfine structure is attributed to a relaxation effect because magnetic susceptibility measurements revealed the glasses to be paramagnetic in the temperature range 78–295 K. A linear decrease in the absorption area and a similar decrease in the internal magnetic field for the hyperfine structure were observed with an increase in the alkali content of glasses. The decrease is ascribed to a formation of non-bridging oxygen at the site adjacent to iron, because the mean life-time of the internal magnetic field produced by 3d-electrons of iron is considered to decrease with increasing thermal vibration of the iron and neighboring oxygens. Fractions of non-bridging oxygens obtained from the reduction rate of the absorption area of hyperfine structure are in good agreement with earlier results for borate glasses with the same K2O/B2O3 ratios, in the alkali region of 8–20 mol% where the borosilicate glasses are essentially considered to be borate glasses diluted with SiO2.
Kinetics of Ligand Substitution Reactions in Trimalonatoyanadium(III)
Authors: Ikeda Yasuhisa , Soya Sumio , Tomiyasu Hiroshi , Fukutomi Hiroshi 
Published: July 2006

Abstract
The kinetics of ligand substitution reactions in trimalonatovanadium(III), V(mal)33−, with various multidentate ligands, malonate (MAL), ethylenediaminetetraacetate (EDTA), and nitrilotriacetate (NTA) have been studied. The rate constant of the malonate exchange in V(mal)33− was obtained from the NMR line-broadening method to be kex=50 s−1 at 70 °C. The rate of EDTA substitution depends on the entering EDTA species. The values of second order rate constants are k21=0.04 M−1 s−1 (1 M=l mol dm−3) for H2edta as an entering ligand and k22=0.25 M−1 s−1 for H3edta at 25 °C. The NTA substitution is reversible under the experimental conditions studied. The apparent rate constants of the forward and backward reactions are k3=1.3×10−2 M−1 s−1 and k−3=2.0×103 M−1 s−1 at pH 3.5 and 25 °C, respectively. The univalent H2nta is found to be the only entering ligand.
Ternary α-Amino Acid-Palladium(II) Complexes with Ligand-Ligand Hydrogen Bonding
Authors: Odani Akira , Yamauchi Osamu 
Published: July 2006

Abstract
Histidinate(His)-containing ternary α-amino acid-palladium(II) complexes have been studied by synthetic and spectroscopic methods. The following complexes with imidazolate (im), l- and d-His, l-asparaginate (l-Asn), and l-glutaminate (l-Gln) have been isolated as crystals: [Pd(im)2]·0.5H2O; [Pd(l-His) (d-His)]·H2O; [Pd(l-Asn)-(l-His)]·2H2O; [Pd(l-Gln) (l-His)]·2H2O. The ternary systems involving palladium (II), l-His, and an amino acid l-AA with an OH or a CONH2 group (AA=Asn, Gln, serinate, threoninate, or homoserinate) exhibit absorption maxima at 300–311 nm with ε 310–440 and negative and positive circular dichroism (CD) peaks at 307–328 nm and ≈300 nm, respectively. 13C and 1H NMR spectra gave the amounts of the cis and trans isomers of Pd(His)-(AA) in solution and confirmed that Pd(His)(AA) has an N3O donor set in the coordination plane. Whereas the CD magnitude additivity holds for the ternary systems Pd (l-His)(B) with B=glycinate, l-alaninate, or l-valinate and the systems with l-histidine methyl ester (l-HisOMe) and l-AA, Pd(l-HisOMe)(l-AA), the magnitudes for Pd (l-His) (l-AA) deviate significantly from those estimated on the basis of the additivity. The CD magnitude anomaly as well as the geometrical and rotational isomer populations calculated from the 1H NMR spectra establishes the existence of the ligand-ligand interaction between the carboxylato group of His and the hydroxyl or amido group of AA in solution.
Synthesis and Properties of S,S-Diaryl Thymidine Phosphorodithioates
Authors: Sekine Mitsuo , Hamaoki Ken , Hata Tsujiaki 
Published: July 2006

Abstract
Appropriately protected or unprotected S,S-diphenyl thymidine 3′- or 5′-phosphorodithioates and S,S-bis(4-methoxyphenyl) thymidine 3′- or 5′-phosphorodithioates were successfully prepared by the reaction of the thymidine derivatives with cyclohexylammonium S,S-diaryl phosphorodithioates in the presence of 2,4,6-triisopropylbenzene-sulfonyl chloride (TPS). Stabilities of the thymidylic compounds under acidic or alkaline conditions were described in detail. Several methods for the deprotection of one or both arylthio groups under neutral conditions were also described in connection with the synthesis of oligothymidylates. By the use of the bis(4-methoxyphenylthio)phosphoryl group, di- and tri-thymidylates were synthesized in high yields.
14N Nuclear Quadrupole Resonance of the Molecular Complexes of Urea
Authors: Negita Hisao , Kubo Tsuneo , Kato Hitoshi 
Published: July 2006

Abstract
The 14N nuclear quadrupole resonance (NQR) was studied in four kinds of molecular complexes of urea, such as urea-nitric acid, urea-phosphoric acid, urea-oxalic acid, and urea-ammonium chloride. The 14N quadrupole coupling constants and asymmetry parameters at liquid nitrogen temperature are as follows: |e2Qq⁄h|=3.157 MHz and η=0.475 for the HNO3 complex; |e2Qq⁄h|=3.277 MHz and η=0.414 for the H3PO4 complex; |e2Qq⁄h|=3.456 MHz and η=0.363 for the (COOH)2 complex; and |e2Qq⁄h|=3.544 MHz and η=0.298 for the NH4Cl complex. From the temperature dependence of the resonance lines in these complexes, the strength of hydrogen bonds are discussed. The differences of the electron densities at the nitrogen atoms between urea and its complexes were derived from the corresponding NQR parameters, and the bond characters in these complexes are discussed.
Studies on Mixed Chelates. XI. Syntheses and Comparative Study of a New Series of Mixed Nickel(II) Chelates with Halide and Pseudohalide Ligands
Authors: Hoshino Naomi , Fukuda Yutaka , Sone Kozo 
Published: July 2006

Abstract
A new series of mixed chelates of nickel(II), Ni(diam) (β-dik)X·nH2O (X= halide or pseudohalide anion, n=0–2), was prepared, and their structures in solid state and in various organic solvents were studied. Most of the chelates were octahedral, many of them being obtained as mono- or dihydrates. When the solid chelates were heated at reduced pressure, the main reactions were dimerization (X=pseudohalide), dehydration (X=I), and disproportionation (X=Br or Cl). On the other hand, the chelates showed complicated structural changes in organic solvents, some of which were not observed in solids, depending upon the nature of X and the polar characteristics of the solvent.
Transition-metal Complexes of Pyrrole Pigments. XIX. Electrochemical and Coordination Behaviors of (5,10,15,20-Tetraphenyl porphinato)niobium(V) Complexes
Authors: Matsuda Yoshihisa , Yamada Sunao , Goto Takashi , Murakami Yukito 
Published: July 2006

Abstract
The redox chemistry of acetato(5,10,15,20-tetraphenylporphinato)oxoniobium(V) (1) was investigated in dichloromethane by means of cyclic voltammetry and controlled potential electrolysis. One-electron reduction potentials were observed at −0.89, −1.05, and −1.41 V vs. SCE for the range from 0 to −2.0 V; the reduction of niobium(V) to niobium(III) occurred prior to ligand-reduction. The potential separation between first and second metal-reductions (ΔE1⁄2) for 1 is 0.16 V, while ΔE1⁄2 between reductions of the MoVI and MoV species for the corresponding molybdenum complex is 1.24 V. In order to elucidate the origin of such potential difference between the niobium and molybdenum complexes, the change of coordination structures which takes place in the course of redox reactions was examined. The coordination reaction of 1 with pyridine was also studied.
Restricted Rotation Involving the Tetrahedral Carbon. XXXVI. Stereodynamics of 9-(2-MethylbenzyI)triptycene Derivatives
Authors: Yamamoto Gaku , Oki Michinori 
Published: July 2006

Abstract
DNMR study of a series of singly peri-substituted 9-(2-methylbenzyl)triptycene derivatives showed that the interconversion among the ap and ±sc rotamers with the o-methyl group pointing outside the triptycyl skeleton occurs by two consecutive gear motion steps by way of the unstable rotamers with the o-methyl group pointing inside. The+sc\ightleftharpoons−sc interconversion barriers (13.2—14.1 kcal/mol) are lower than the ap\ightleftharpoons±sc ones (17.7–20.8 kcal/ mol). The aryl group passes over a peri-hydrogen at the transition state of the former process and over the peri-substituent in the latter.
Chiral and Stereoselective Total Synthesis of (−)-Deoxoprosopinine and (−)-Deoxoprosophylline. Intramolecular Amino mercuration of an ε,ζ-Unsaturated Amine
Authors: Saitoh Yutaka , Moriyama Yoshihiko , Hirota Hiroshi , Takahashi Takeyoshi , Khuong-Huu Qui 
Published: July 2006

Abstract
l-Serine was transformed in 8 steps into (4R,5S)-2,2-dimethyl-4-[(Z)-3-pentadecenyl]-1,3-dioxan-5-amine. This chiral ε,ζ-unsaturated amine was subjected to intramolecular aminomercuration and then acid hydrolysis to give (−)-deoxoprosopinine and (−)-deoxoprosophylline.