bluuebunny/crossref_metadata_2025_split huggingface dataset:
Sialic acid patterns in N‐linked carbohydrate chains. Structural analysis of the N‐acetyl‐/N‐glycolyl‐neuraminic‐acid‐containing N‐linked carbohydrate chains of bovine fibrinogen
Authors: Damm J. B. L. , Bergwerff A. A. , Hård K. , Kamerling J. P. , Vliegenthart J. F. G. 
Published: September 2010

AbstractThe N‐linked carbohydrate chains of bovine fibrinogen have been released by peptide‐N4‐(N‐acetyl‐β‐glucosaminyl)asparagine amidase‐F, fractionated by FPLC and HPLC procedures and characterized by 500/600‐MHz 1H NMR spectroscopy. Evidence is presented for the native sialic acid patterns, involving the occurrence of α2 → 6‐linked N‐acetyl‐ and N‐glycolylneuraminic acid residues in the terminal position of the di‐antennary carbohydrate chains. Details are included of minor oligosaccharides containing Neu5Acα2 → 3Galβ 1→ 4/β1 → 3GlcNAc β1 → structural elements, which have not been previously described in this glycoprotein.
Biosynthesis of blood‐group‐I and ‐i antigens. A specific assay for a developmentally regulated β6‐N‐acetylglucosaminyltransferase. Application to normal and malignant hematopoietic cells
Authors: Koenderman Anky H. L. , Koppen Piet L. , van den Eijnden Dirk H. , Wijermans Pierre W. , Langenhuijsen Mart M. A. C. 
Published: September 2010

AbstractA specific assay for the activity of UDP‐GlcNAc: β‐galactoside β6‐N‐acetylglucosaminyltransferase B has been developed. The assay is based on the use of the specific acceptor Galβ1 → 3Galβ1 → 4Glc and the analysis and characterization of the product by HPLC. Using this assay, the role of the transferase in the developmentally regulated expression of the GlcNAcβ1 →3(GlcNAcβ1 → 6)Gal branching points in blood‐group‐I‐active polylactosaminogly‐cans, as well as the Galβ1 → 3(GlcNAcβ1 → 6)GalNAc core‐type‐2 structure of O‐linked carbohydrates, has been investigated in normal and malignant hematopoietic cells. In the erythroid, myeloid and the monocytic system, the activity of the transferase appeared to decrease with differentiation and maturation. This decrease is opposite to that which would be expected on the basis of available structural and immunological data, which suggest that branching of polyactosaminoglycans and/or formation of core‐type‐2‐based O‐linked chains, resulting in the expression of I activity, increase with maturation.It is possible that more than one β6‐N‐acetylglucosaminyltransferase B activity is implicated in the synthesis of β6‐GlcNAc‐containing structures; the alternative is that the enzyme, assayed with Galβ1 → 3Galβ1 → 4Glc, is involved but that the expression of these structures is also dependent on low activities of competing glycosyltransferases. On the other hand, the synthesis of the branching points in polylactosaminoglycans might proceed through an alternative reaction sequence involving β6‐N‐acetylglucosaminyltransferase A.
Syntheses of tri‐ and tetrasaccharide fragments of the capsular polysaccharide of Streptococcus pneumoniae type 23F
Authors: van Steijn A. M. P. , Jetten M. , Kamerling J. P. , Vliegenthart J. F. G. 
Published: September 2010

AbstractThe syntheses of two trisaccharides, being fragments of the capsular polysaccharide of Streptococcus pneumoniae type 23F (3‐OPO2−3)‐β‐D‐Glcp‐(1‐4)‐[α‐L‐Rhap‐(1‐2)]‐β‐D‐Galp‐(1‐OCH3) (1), α‐L‐Rhap‐(1‐2)‐β‐D‐Galp‐(1‐4)‐β‐L‐Rhap‐(1‐OCH3) (2) and the repeating unit (3‐OPO32−)‐β‐D‐Glcp‐(1‐4)‐[α‐L‐Rhap‐(1‐2)]‐β‐D‐Galp‐(1‐4)‐β‐L‐Rhap‐(1‐OCH3) (3), are presented.
The role of axial chirality in schiff bases of pyridoxal phosphate and amino acids in the mechanism of racemase enzymes. A quantum‐chemical study
Authors: van Genderen Marcel H. P. , Buck Henk M. 
Published: September 2010

AbstractIn the enzymatic racemization of L and D amino acids, the coenzyme pyridoxal phosphate (PLP) forms a Schiff base with the amino acid. In the first step of the isomerization reaction, both the L and D PLP‐amino acid compounds are deprotonated by a single basic site in the enzyme, which is normally assumed to occur via large conformational changes of coenzyme or enzyme. We propose a more efficient mechanism in which axial chirality is introduced into the PLP‐amino acid complex by a rotation around the C4C4′ bond, placing the iminium side‐chain in an out‐of‐plane orientation. This allows optimal location of both L and D amino acids for deprotonation by one basic site in the enzyme. A combination of the calculated results with the kinetic data of Farad and Walsh (Biochemistry 27, 3267 (1988)) provides insight into the location of the catalytic base in the enzyme with respect to the coenzyme.
The weak‐overlap bond: An SGF (Simplified Group Function) analysis
Authors: Schipper Pieter E. 
Published: September 2010

AbstractSubstituent and solvent effects in reactivity and spectroscopy, as well as bonding in Van der Waals and/or hydrogen‐bonded dimers, fall within the weak‐to‐zero‐overlap regime. The simplified group function (SGF) approach coupled with a fixed spin (FS) electronic representation is shown to lead to a systematic theoretical development of the wave function in this bonding region in a manner paralleling intuitive chemical thinking; i.e. in terms of labelled electrons of fixed spin “jumping” between specific‐group orbitals (FS activity). The readily visualizable resolution into types of FS activity is shown to also underlie the formal theoretical resolution of the SGF wave function, and thus any observables derived from it. In particular, the energetics of the weak‐overlap bond (the SGF potential) is developed in the perturbative limit of mixing excitation structures, leading to additive long‐range (overlap independent: static, inductive, dispersive) and short‐range (overlap dependent: dative, codative, covalent and Pauli‐induced) contributions. An important feature of SGF methodology in analytic application to substituent and solvent effects is that simplification of the wave function is achieved through systematic suppression of interchange activity, thereby retaining the full form of the Hamiltonian including, e.g., electron‐electron repulsion). This is demonstrated in a range of applications: viz. (i) to a justification for frontier‐orbital theory and the angular‐overlap model; (ii) to a description of substituent effects in aromatic electrophilic substitution; and (iii) to the development of a simple framework for discussing solvent/ligand effects on solute/metal transition energies.
A kinetic study of the alkaline hydrolysis of four‐coordinated phosphorus (PIV) compounds. Impact of conformational transmission in the transiently formed five‐coordinated (PV‐TBP) intermediates on reaction rate and product distribution
Authors: Koole Leo H. , Olders Edith A. T. A. , Opresnik Marko , Buck Henk M. 
Published: September 2010

AbstractIt can be shown that alkaline hydrolysis of four‐coordinated phosphorus (PIV) compounds is substantially accelerated if the trigonal‐bipyramidal (TBP) five‐coordinated phosphorus (PV) intermediate in the reaction can exhibit conformational transmission. With the compounds 5a‐c, it was shown that this acceleration is an entropy effect. Pseudorotation in the PV‐TBP intermediate is facilitated if conformational transmission occurs, and therefore the entropy loss during build‐up of the PV‐TBP is reduced. This evidently results in a lower free energy of activation for the reaction. For the phosphate triester systems 6a and 6b, it was also found that the occurrence of conformational transmission speeds up the hydrolysis reaction, although the effect is less pronounced than for compounds 5a‐c. The cyclopentylmethoxy group (6a) and the tetrahydrofurfuryloxy group (6b) show slight preferences for equatorial and axial positioning in the transient PV‐TBP, respectively. This study shows for the first time that reaction rate and product selectivity of hydrolyses of phosphate esters can be determined in part by the conformational transmission effect.
Study of propene metathesis on MoO3−x/Al2O3 catalysts; effect of diazomethane decomposition
Authors: Ghazi M. , Sachtler W. M. H. 
Published: September 2010

AbstractPropene metathesis has been studied at 295 K and 1 atm in He or in H2 with MoO3−x/Al2O3 catalysts which were reduced at 673 K. Some catalysts were modified by exposing them to diazomethane vapor prior to testing. The diazomethane was synthesized shortly before use; it was stored by dissolving its vapor in di‐n‐butyl phthalate. Metathesis of the unmodified catalysts revealed an induction period during which the activity increased; this period is markedly shorter in H2 than in He. In He, metathesis is the sole reaction, in H2 it is accompanied by a prevailing hydrogenolysis. No induction period is visible for catalysts modified with diazomethane in accordance with the assumption that surface carbenes are reaction intermediates. The activity is, however, lowered by this treatment, as catalyst deactivation is enhanced by the pretreatment with diazomethane.
Mechanistic studies of the oxidative‐coupling polymerization of 2,6‐dimethylphenol. Part II. Specificity of the reaction and formation of diphenoquinone
Authors: Viersen F. J. , Challa G. , Reedijk J. 
Published: September 2010

AbstractCopper‐(N,N,N′,N′‐tetramethylethylenediamine) (tmed) complexes as catalysts in the oxidative‐coupling polymerization of 2,6‐dimethylphenol (DMP) give rise to poly(2,6‐dimethyl‐1,4‐phenylene oxide) (PPO) in high yield, although the formation of the undesired 3,5,3′,5′‐tetramethyldiphenoquinone (DPQ) cannot be completely avoided.At ligand‐to‐copper ratios lower than 10, the specificity for PPO formation can be raised by increasing the N/Cu ratio and by the addition of a strong base (potassium or lithium hydroxide). However, once a fivefold excess of tmed is used, neither further tmed nor hydroxide addition raises the specificity beyond 97% PPO. Using an N/Cu ratio of 10, neither the catalyst concentration nor the DMP concentration has an effect on the product composition.On the basis of the experimental results included in this paper, together with those published in the literature, it is concluded that the specificity is not affected by the structure of the copper complex, provided that sufficiently high ligand‐to‐copper ratios are used. This results in a product formation which always consists of ca. 3% of DPQ and 97% PPO. The DPQ is formed mainly during the initial stages of the reaction.However, final DPQ yields of up to 45 % are found for N/Cu < 4. High concentrations of mononuclear copper species Cu(tmed)22+ appear to be present under these conditions as deduced from EPR experiments (in addition to polynuclear CuxCly species). Based on this observation, a radical mechanism for DPQ formation, using Cu(tmed)22+ as oxidation catalyst, is proposed. There are thus two distinct reaction conditions: (1) At high N/Cu ratios, the highly active dinuclear complex yields 97% polymer and ca. 3% DPQ. In this case, however, factors which would influence the structure or concentration of the catalyst do not appear to affect the specificity. (2) At low N/Cu ratios, the presence of high concentrations of mononuclear Cu(tmed)22+ results in high yields of DPQ and in this case, the hydroxide concentration strongly affects the specificity.
pH‐Dependence in the Cu(I)‐mediated oxidation of toluene with oxygen or hydrogen peroxide
Authors: Okunowski J. K. , van Dam H. E. , van Bekkum H. 
Published: September 2010

AbstractpH is shown to exert a profound effect on the selectivity of the Cu(I)‐mediated oxidation of toluene with oxygen or hydrogen peroxide. At low pH, methyl‐group oxidation predominates, whereas at pH > 3, ring hydroxylation prevails. A common mechanism for oxygen and hydrogen peroxide oxidation is suggested.
The effect of alloying on the adsorption of nitric oxide on platinum and rhodium (100). A TDS study using a Pt‐Rh(100)‐alloy single‐crystal surface
Authors: Siera J. , van Groos M. J. Koster , Nieuwenhuys B. E. 
Published: September 2010

AbstractThe adsorption and dissociation of NO have been studied on a Pt‐Rh(100)‐alloy single‐crystal surface by thermal‐desorption spectroscopy (TDS). It was found that, at low coverages, NO dissociates completely upon heating to form N2 and O2. At higher coverages, NO desorption was observed, in addition to desorption of N2, and two new N2 desorption peaks appeared. Three N2 desorption peaks were distinguished. The results are compared with literature data concerning NO adsorption on Rh(100) and Pt(100). It is concluded that, at low coverages, the Rh sites are responsible for NO bond scission activity.
The cycloaddition reaction of α‐oxo sulfines and 2‐trimethylsilyloxy‐1,3‐butadienes
Authors: Rewinkel J. B. M. , Zwanenburg B. 
Published: September 2010

AbstractThe cycloaddition reaction of α‐oxo sulfines with 2‐(trimethylsiloxy)‐1,3‐dienes, leading ultimately to thiacyclohexanone S‐oxides (alternatively named as thianone S‐oxides or perhydrothiapyranone S‐oxides) is described. 1‐Oxo‐2‐thioxo‐indane S‐oxide 2a, and several α‐oxo sulfines generated in situ have been studied. The cycloaddition reaction is regioselective, and thiacyclohexan–3‐one S‐oxides are the preponderant or the exclusive products. In the case of 1‐ethoxy‐3‐(tri‐methylsiloxy)‐1,3‐butadiene 3c the primary cycloadduct with sulfine 2a can either undergo mild hydrolysis to give a thiacyclohexan‐3‐one S‐oxide 6h or elimination to give thia‐4‐cyclohexen‐3‐one S‐oxide (2,6‐dihydrothiapyran‐3‐one S‐oxide) 6i. The regiochemistry of these cycloadditions is discussed in terms of HOMO/LUMO coefficients.
Synthesis and transport properties of rigid poly(octasubstituted phthalocyaninatosiloxanes)
Authors: van der Pol J. F. , Zwikker J. W. , Warman J. M. , de Haas M. P. 
Published: September 2010

AbstractCoaxially polymerized, peripherally substituted derivatives of phthalocyanine (‐[SiPc(CnH2n+ 1)8‐O‐]; n = 8, 12) have been synthesized and characterized. They display efficient energy‐migration properties and a dark conductivity at room temperature of 2 × 10−2 S · m−1, even in the absence of dopants. The temperature dependence of the conductivity for the C8 derivative, over the range ‐ 50 to + 200°C, is given, to a good approximation, by σ = 1.5 · exp [‐ Ea/(kB · T)] S · m−1 with an activation energy Ea of 0.11 eV (2.5 kcal/mole). This material could be an example of an intrinsic, one‐dimensional conducting polymer.
Collision‐induced dissociation reactions of o‐, m‐ and p‐methoxyphenyl anions in the gas phase
Authors: Visser Remco , Maas Wilfried P. M. , Nibbering Nico M. M. 
Published: September 2010

AbstractOn the basis of collision‐induced‐dissociation experiments, we show that o‐, m‐ and p‐methoxyphenyl anions, generated under negative‐chemical‐ionization (NCI) conditions from the corresponding ethyl methoxybenzoates, are distinct species.The main collision‐induced‐dissociation channel for the o‐methoxyphenyl anion is formaldehyde loss. This ion also loses a CH2 moiety, which indicates that it can rearrange to a stable C6H5OCH2− primary carbanion.Methyl‐radical loss is the major collision‐induced‐dissociation channel for both the m‐ and p‐methoxyphenyl anions. The kinetic energy release accompanying this dissociation is significantly larger for the former anion than for the latter. It is suggested that this is due to a greater stability of the product radical ion, if generated from the m‐methoxyphenyl anion rather than from the p‐methoxyphenyl anion.
Chemo‐enzymatic synthesis and characterization of L‐tryptophans selectively 13C‐enriched or hydroxylated in the six‐membered ring using transformed Escherichia coli cells
Authors: van den Berg E. M. M. , Jansen F. J. H. M. , de Goede A. T. J. W. , Baldew A. U. , Lugtenburg J. 
Published: September 2010

AbstractL‐(3a‐13C)‐ And L‐(6‐13C)tryptophan have been synthesized from simple labelled compounds via a single reaction scheme based on the conversion of 1,3‐cyclohexanedione into indole. The labelled indoles have been converted in one step into the corresponding L‐tryptophans using transformed Escherichia coli cells with large amounts of the enzyme, tryptophan synthetase. The same reaction scheme has been used for the synthesis of 4‐ and 7‐indolol. These hydroxyindoles together with 5‐indolol have been converted into 4‐, 7‐ and 5‐hydroxy‐L‐tryptophan, respectively, using the Escherichia coli cells. The latter compound is the immediate precursor of the neurotransmitter, serotonin. It appears that 7‐indolol is the only indole derivative which is converted faster than unsubstituted indole by the enzyme, tryptophan synthetase. With the preparation of L‐(3a‐13C)‐ and L‐(6‐13C)tryptophan, we have completed the series of indoles and L‐tryptophans with a stable isotope (13C, 15N or 2H) in the aromatic ring. In this paper, we also discuss the NMR parameters of these mono‐isotopically labelled systems.
Modification of papain with a NAD(P)H analogue. Reactivity towards charged substrates and enhanced stability towards acid catalyzed hydration
Authors: Broos Jaap , Kellogg Richard M. 
Published: September 2010

AbstractAn N‐alkylnicotinamidium salt has been linked covalently to Cys 25 of papain and thereafter reduced to the 1,4‐dihydro form. Reactions of this material have been examined.
Phosphino‐stabilized allyl anions and trimethylenemethane dianions
Authors: van Doom J. A. , van der Heijden H. 
Published: September 2010

AbstractPhosphino‐stabilized allyl anions are formed by deprotonation of phosphinopropenes with alkyllithium. A double deprotonation of 2‐diphenylphosphinomethyl‐3‐diphenylphosphinopropene leads to interesting phosphino‐stabilized trimethylenemethane dianions. Alkylation with methyl iodide occurs at a carbon atom and not at a phosphorus centre.
Stereoselective reduction of benzoin by the NADH model 3‐(dimethylcarbamoyl)‐1,2,4‐trimethyl‐1,4‐dihydropyridine
Authors: Beijer Nicoline A. , Vekemans Jozef A. J. M. , Buck Henk M. 
Published: September 2010

AbstractThe Mg(ClO4)2‐induced reduction of racemic benzoin by the racemic NADH model compound 3‐(dimethylcarbamoyl)‐1,2,4‐trimethyl‐1,4‐dihydropyridine (1), in accordance to Cram's rule, leads exclusively to meso‐1,2‐diphenyl‐1,2‐ethanediol. However, while R‐1 equally reduces 5‐benzoin to afford meso‐1,2‐diphenyl‐1,2‐ethanediol, S‐1 is reluctant to react with S‐benzoin. The intermediacy of a strictly organized transition state, composed of chelated substrate, dihydropyridine and magnesium ion is involved.
Selective nucleophilic displacement of a methoxy group in 1,2,3‐trimethoxybenzenes
Authors: Budzelaar P. H. M. , van Doorn J. A. 
Published: September 2010

AbstractA methoxy group in 1,2, 3‐trimethoxybenzenes can be readily displaced by a butyl group via reaction with butyllithium in hexane. The reaction probably proceeds via an addition‐elimination mechanism. There appears to be a qualitative relation between the coefficient of the LUMO at the central C‐O carbon atom and the rate of the reaction.
Synthesis of oligodeoxynucleotides containing thymidines linked via an internucleosidic‐(3′‐5′)‐methylene bond
Authors: Veeneman G. H. , van der Marel G. A. , van den Elst H. , van Boom J. H. 
Published: September 2010

AbstractCondensation of N3‐benzoyl‐5′‐O‐dimethoxytrityl‐3′‐O‐(4‐penten‐1‐oxymethyl)‐thymidine with N3‐benzoyl‐3′‐O‐methoxyacctyl‐thymidine, in the presence of N‐iodosuccinimide, afforded a fully‐protected thymidine dimer having an internucleosidic‐(3′‐5′)‐methylene linkage. The latter was utilized in the preparation, in solution and on a solid support, of DNA‐fragments containing one or more T‐CH2‐T dimer(s).
Dimetallation of benzene
Authors: Lochmann L. , Fossatelli M. , Brandsma L. 
Published: September 2010

AbstractUsing the combination of n‐butyllithium and soluble potassium t‐alkoxides higher ratios of di‐and mono‐metallated benzene have been attained than with n‐butyllithium and the insoluble t‐BuOK.
A liquid‐crystalline poly(iminomethylene) with cholesterol‐containing pendant groups
Authors: van Walree C. A. , van der Pol J. F. , Zwikker J. W. 
Published: September 2010

AbstractTwo poly(iminomethylenes) with cholesterol‐containing pendant groups were synthesized. Using an aliphatic spacer, a liquid‐crystalline polymer was obtained, with equal amounts of right‐and left‐handed helices. With phenylene as bridging group, only oligomers resulted, probably for steric reasons. Some novel liquid‐crystalline esters of cholesterol are also presented.
Synthesis of plastoquinone derivatives with different structures of the side chain
Authors: Liu Benli , Gu Lianquan , Zhang Jingling 
Published: September 2010

AbstractTwo schemes for the synthesis of plastoquinone derivatives with ω‐substituted alkyl side chains have been developed, based on radical alkylation of 2,3‐dimethyl‐1,4‐benzoquinone with ω‐substituted carboxylic and/or dicarboxylic acids in the presence of S2O2−8 and Ag+. In Scheme 1, radical alkylation of 2,3‐dimethyl‐1,4‐benzoquinone with 11‐bromoundecanoic acid, in the presence of (NH4)2S2O8 and AgNO3, gave 2,3‐dimethyl‐5‐(10‐bromodecyl)‐1,4‐benzoquinone, which, after hydration, gave 2,3‐dimethyl‐5‐(10‐hydroxydecyl)‐1,4‐benzoquinone. Esterification of 2,3‐dimethyl‐5‐(10‐hydroxydecyl)‐1,4‐benzoquinone with different acyl chlorides gave 2,3‐dimethyl‐5‐(10‐acyloxy‐decyl)‐1,4‐benzoquinone. In Scheme 2, radical alkylation of 2,3‐dimethyl‐1,4‐benzoquinone with adipic acid, in the presence of K2S2O8 and AgNO3, gave 2,3‐dimethyl‐5‐(4‐carboxybutyl)‐1,4‐benzo‐quinone, which was converted to 2,3‐dimethyl‐5‐[4‐(alkoxycarbonyl)butyl]‐1,4‐benzoquinone by esterification with different alcohols in the presence of dicyclohexylcarbodiimide. 2,3‐Dimethyl‐5‐(8‐carboxyoctyl)‐1,4‐benzoquinone and 2,3‐dimethyl‐5‐[8‐(alkyloxycarbonyl)octyl]‐1,4‐benzoquinone were similarly synthesized from 2,3‐dimethyl‐1,4‐benzoquinone and sebacic acid. Plastoquinone derivatives having different kinds of double bonds in the side chain with and without a 6‐methyl group were synthesized from 2,3,5‐trimethyl‐1,4‐benzoquinone and 2,3‐dimethyl‐1,4‐benzoquinone by successive reactions with (l)NaBH4; (2)KHSO4, different kinds of allylic alcohols; (3) Ag2O. The allylic alcohols were prepared from their corresponding aldehydes by reduction with NaBH4. 2,3,6‐Trimethyl‐1,4‐benzoquinone was prepared from 2,3‐dimethyl‐1,4‐benzoquinone by radical methylation with acetic acids in the presence of K2S2O8+ AgNO3.
Enzymatic optical resolution of a synthetic pyrethroid alcohol. Enantioselective transesterification by lipase in organic solvent
Authors: Mitsuda Satoshi , Nabeshima Shigeyasu 
Published: September 2010

AbstractTo obtain (S)‐4‐methyl‐1‐heptyn‐4‐en‐3‐ol [(S)‐1a], enzymatic enantioselective esterification of (R,S)‐1a in organic solvent was examined. Pseudomonas lipase catalyzed the transesterification of (R,S)‐1a with vinyl acetate in n‐hexane, and gave (S)‐1a and the corresponding acetate of (R)‐1a with good enantioselectivity and high reaction rate. The reaction was accelerated by increasing the hydrophobicity of the organic solvent used as reaction medium and decreasing the water content of the reaction mixture. Under optimum conditions, (S)‐1a of 99% ee was obtained at a conversion ratio of 68.6%. A kinetic udy revealed that the enzymatic reaction proceeded under the ping‐pong mechanism involving the acyl‐enzyme as an intermediate.
Formation of a distibacyclooctane; X‐ray crystal structure of 1,5‐dichloro‐1,3,3,5,7,7‐hexamethyl‐9‐oxa‐1,5‐distibabicyclo[3.3.1]nonane hydrochloride
Authors: Tinga M. A. G. M. , Groeneveld M. K. , Akkerman O. S. , Bickelhaupt F. , Smeets W. J. J. , Spek A. L. 
Published: September 2010

AbstractThe reaction of methylantimony dichloride with (2,2‐dimethyl‐1,3‐propanediyl)bis(magnesium bromide) (1), followed by oxidation with sulfuryl chloride and partial hydrolysis, gave the title compound 7. No evidence could be obtained for the formation of a stibacyclobutane in this reaction. Crystals of the title compound were block shaped, space group Pl̄ with a = 8.901(1), b = 9.378(1), c = 12.084(2) Å, α = 80.61(1), β = 89.01(1), γ = 72.41(1)°. The structure was solved using standard Patterson and Fourier methods and refined by full‐matrix least‐squares techniques to a final R = 0.036 for 3356 observed reflections.