Macrocyclic Spermine Alkaloids from Verbascum: The (E/Z)-Isomeric Pairs (−)-(S)-Verbasitrine/(−)-(S)-Isoverbasitrine and (+)-(S)-Verbametrine/(+)-(S)-Isoverbametrine: Isolation,Structure Elucidation,and Synthesis

The isolation and structure elucidation of the 17-membered macrocyclic spermine alkaloids (−)-(S)-verbasitrine ( 2 ), (−)-(S)-isoverbasitrine ( 4 ), (+)-(S)-verbametrine ( 6 ), and (+)-(S)-isoverbametrine ( 8 ) is presented. The synthesis of their racemates is described.     

Chiral Tetraamines Based on (S)-2-(Aminomethyl)pyrrolidine: Template synthesis and properties of copper(II) complexes

The template reaction of {bis[(S)-2-(aminomethyl)pyrrolidine]}copper(II) with formaldehyde, nitroethane, and base in MeOH yields optically pure {1,7-bis[(S)-pyrrolidin-2-yl]-4-methyl-4-nitro-2,6-diazaheptane}- copper(II) ([Cu((S,S)-mnppm)]²⁺) in high yield. The same reaction with rac-2-(aminomethyl)pyrrolidine is also described. Preparative details and spectroscopic and electrochemical properties of the Cu^II complexes and of the free ligands are reported and compared with structural, spectroscopic and electrochemical data of the Cu^II complex of the unsubstituted parent ligand 1,7-bis[(S)-pyrrolidin-2-yl]-2,6-diazaheptane (ppm). The crystal structure of [Cu(ppm)]Cl ClO₄ has been determined by X-ray diffraction methods.     

Asymmetric Syntheses of the Macrocyclic Spermine Alkaloids (−)‐(S)‐Protoverbine, (−)‐(S)‐Buchnerine,and Their Naturally Occurring Congenial Alkaloids

Asymmetric syntheses of the following 17‐membered macrocyclic spermine alkaloids are presented: (−)‐(S)‐protoverbine (=(8S)‐8‐phenyl‐1,5,9,13‐tetraazacycloheptadecane‐6‐one; 1 ), (+)‐(S)‐protomethine (=(2S)‐2‐phenyl‐1,5,9,14‐tetraazabicyclo[12.3.1]octadecan‐4‐one; 2 ), (−)‐(S)‐buchnerine (=(8S)‐8‐(4‐methoxyphenyl)‐1,5,9,13‐tetraazacycloheptadecane‐6‐one; 8 ), (+)‐(S)‐verbamethine (=(+)‐(2S)‐9‐[(E)‐phenylprop‐2‐enoyl]‐2‐phenyl‐1,5,9,14‐tetraazabicyclo[12.3.1]octadecan‐4‐one; 4 ), (−)‐(S)‐verbacine (=(−)‐(8S)‐1‐[(E)‐phenylprop‐2‐enoyl]‐8‐phenyl‐1,5,9,13‐tetraazacycloheptadecan‐6‐one; 3 ), (−)‐(S)‐verbasikrine (=(−)‐(8S)‐1‐[(E)‐3‐(4‐methoxyphenyl)prop‐2‐enoyl]‐8‐phenyl‐1,5,9,13‐tetraazacycloheptadecan‐6‐one; 26 ), (−)‐(S)‐isoverbasikrine (=(−)‐(8S)‐1‐[(Z)‐3‐(4‐methoxyphenyl)prop‐2‐enoyl]‐8‐phenyl‐1,5,9,13‐tetraazacycloheptadecan‐6‐one; 25 ), (+)‐(S)‐verbamekrine (=(+)‐(2S)‐9‐[(E)‐3‐(4‐methoxyphenyl)prop‐2‐enoyl]‐2‐phenyl‐1,5,9,14‐tetraazabicyclo[12.3.1]octadecan‐4‐one; 23 ), and (+)‐(S)‐isoverbamekrine (=(+)‐(2S)‐9‐[(Z)‐3‐(4‐methoxyphenyl)prop‐2‐enoyl]‐2‐phenyl‐1,5,9,14‐tetraazabicyclo[12.3.1]octadecan‐4‐one; 24 ). Effective methods for ¹H‐NMR determination of the enantiomeric purity in which (S)‐2‐hydroxy‐2‐phenylacetic acid and (S)‐2‐acetoxy‐2‐phenylacetic acid are used as shift reagents for 1, 8 , and related macrocyclic alkaloids are described.     

C45- and C50-Carotehoids. Part 8. Synthesis of (all-E,2S,2′S)-bacterioruberin, (all-E,2S,2′S)-monoanhydrobacterioruberin, (all-E,2S,2′S)-bisanhydrobacterioruberin, (all- E,2R,2′R)-3,4,3′,4′-tetrahydrobisanhydro- bacterioruberin,and (all-E,S)-2-isopentenyl-3,4-dehydrorhodopin

Starting from (R)-3-hydroxybutyric acid ((R)- 10 ) the C₄₅- and C₅₀-carotenoids (all-E,2S,2′S)-bacterioruberm ( 1 ), (all-E,2S,2′S)-monoanhydrobacterioruberin ( 2 ), (all-E,2S,2′S)-bisanhydrobacterioruberin ( 3 ), (all-E,2R,2′R)-3,4,3′,4′-tetrahydrobisanhydrobacterioruberin ( 5 ), and (all-E,S)-2-isopentenyl-3,4-dehydrorhodopin ( 6 ) were synthesized. By comparison of the chiroptical data of the natural and the synthetic compounds, the (2S)- and (2′S)-configuration of the natural products 1–3 and 6 was established.     

Isolierung von (2S, 4S)-(+)-γ-Hydroxynorvalin und (2S, 4R)-(−)-γ-Hydroxynorvalin aus Boletus satanas Lenz

We have isolated from the carpophores of Boletus satanas Lenz (Basidiomycetae) (2S,4S)-(+)-γ-hydroxynorvaline ( 1 ) and (2S,4R)-(?)-γ-hydroxynorvaline ( 2 ). The chirality of each diastereomer has been determined by chemical synthesis starting from optically active precursors and by application of different chiroptical methods. Gaschromatographic separation of the derived diastereomeric N-[(S)-α-methoxypropionyl]-lactones reveals that the optical purity of natural 2 is 88% whereas 1 exists as a partial racemate: (2S,4S): (2R,4R) = 3:2. Muscarine could not be detected in the carpophores of B. satanas, contrary to some literature data but basic substances of unknown structure are present in low concentration.     

[1,2‐P2S8]2− – a New Member of the Thiophosphate Family: Synthesis,Crystal Structure and Vibrational Spectrum of [NH4(2.2.2‐cryptand)]2[1,2‐P2S8] and [NH4(18‐crown‐6)]2[1,2‐P2S8]·H2O

Colourless block‐shaped crystals of [(NH₄)₂(2.2.2‐cryptand)₂][P₂S₈] ( 1 ) and [(NH₄)₂(18‐crown‐6)₂][P₂S₈]·H₂O ( 2 ) could be obtained by the reaction of an aqueous solution of ammonium hexathiohypodiphosphate, (NH₄)₄P₂S₆·2 H₂O, with sulfur and 2.2.2‐cryptand or 18‐crown‐6. The crystal structures of both compounds have been determined by single‐crystal X‐Ray diffraction analysis. Compound 1 crystallizes in the monoclinic space group C2/c with a = 2032.7(2), b = 1243.6(2), c = 2244.6(2) pm, β = 98.64(1)°, and Z = 8, whereas compound 2 crystallizes also monoclinic in the space group P2₁/c with a = 2121.3(2), b = 865.5(1), c = 2345.4(2) pm, β = 91.96(1)°, and Z = 4. It could be established that the title compounds contain a new type of six‐membered [1,2‐P₂S₄] ring with P – P bond and three S – S linkages. The tetrahedral environment of each phosphorus is completed by a (formally) single and double bonded sulfur atom attached externally to the [1,2‐P₂S₄] ring. These terminal PS₂ units are mesomerically stabilized according to their P – S distances. FT‐IR and FT‐Raman spectra of the title compounds are recorded and interpreted.     

Synthesis of (+)-(4S, 8R)hyphen;8hyphen;Epi- and (−)-(4R, 8S)-4-Epi-β-bisabolol

The first total enantioselective synthesis of (+)-(4S, 8R)-8-epi-β-bisabolol(+)- 1 and of (?)-(4R, 8 S )-4-epi-β-bisabolol ((?))? 1 ) is reported. The key step in the synthesis is the kinetic resolution of (±)? 5 by means of the Sharpless epoxidation yielding (?)- and (+}? 6 , respectively. Reduction of the epoxides with LiAlH₄ gave the diols (+)-and(?)? 7 which were transformed into (+)- and (?)? 8 , respectively, via the corresponding mesylate. Reaction of these epoxides with the Grignard reagent derived from homoprenylbromide, assisted by Li₂CuCl₄, finished the synthesis of the target compounds 1 with high diastereo- and enantioselectivity.     

Mixed Ligand Complexes of Cobalt(II) – Synthesis,Structure, and Properties of Co4(thd)4(OEt)4

Synthesis, crystal structure, thermal stability, and magnetic properties of mixed‐ligand complexes of cobalt(II) with ß‐diketonato (thd = C₁₁H₁₉O₂^?) and alkoxides (OR mainly OMe = methoxide = CH₃O^? or OEt = ethoxide = C₂H₅O^?) are reported. Direct reaction between Co(thd)₂ ( 1 ) and EtOH gives a new complex with the structural formula [Co₄(thd)₄(OEt)₄] ( 2 ) whereas MeOH correspondingly reacts to [Co₄(thd)₄(OMe)₄(MeOH)₄] ( 3 ). The yield of these products decreases with increasing size of the R group owing to increased solubility of 1 in the alcohol. The structure of 2 is determined from single‐crystal X‐ray diffraction data. At 100 K 2 takes a monoclinic structure (space group C2/c): a = 15.108(2), b = 19.428(2), c = 21.240(3) Å, and β = 108.882(2)°. At 295 K 2 has transformed to a closely related orthorhombic structure (space group Fddd): a = 15.233(3), b = 19.712(3), c = 40.916(7) Å. Protracted hydrolysis accompanied by oxygenation of complexes 2 and 3 in laboratory air (viz. simultaneous exposure to moisture and oxygen) leads to a new complex 4 with empirical formula corresponding to [Co(thd)(OH)(O₂)]. Magnetic susceptibility data show that Co takes the valence state II in all complexes 1 – 4 . For 4 this implies that dioxygen has to form an adduct‐like association to the rest of the complex. Unfortunately complex 4 has hitherto only been obtained in the amorphous state, but all here produced evidences point at 4 as a distinct entity and that products of 4 obtained from 2 and 3 are chemically identical (but differ somewhat with regard to short‐ and longer‐range order in the atomic arrangement). The interatomic distances in the crystal structure of complexes 1 – 3 are briefly discussed in terms of the bond‐valence concept.     

Synthesis,structure and electrochemistry of dithiocarbamato phenthiolate oxo-molybdenum(IV) complexes [MoO(SΦ)2(S2CNEt2)]-

The reaction of Mo(0) complex [Mo(CO)₄(S₂CNEt₂)]- with phenthiolate [Et₄N]SΦ in acetonitrile in the presence of small amount of air affords a new oxo-molybdenum complex [MoO(SΦ)₂(S₂CNEt₂)], which crystallizes in two forms of crystals. [Et₄N][MoO(SΦ)₂Φ(S₂CNEt₂)] (1a) and [Et₄N][MoO(SΦ)₂(S₂CNEt₂)]Φ(CH₃)₂CHOH (1b). The structures of 1a and 1b were determined from three-dimensional X-ray data. 1a crystallizes in the monoclinic, space group C_e with a=12.321(4), b=15.245(4), c=16.087(9)Å; β= 98.44(4)Φ, V=2989ų, Z=4, D_c = 1.35g/cm³ and R=0.031 for 2434 reflections [I>36(I)]. 1b crystallizes in the monoclinic space group F2₁/n with a=9.861(1), b=20.357(3), c=17.122(5)Å; β= 92.27 (2)*, V=3434.3ų, Z=4; D_e = 1.29g/cm³ and R= 0.051 for 2852 independent reflections [I>3σ(I)]. The structures of 1a and 1b reveal that the anion [MoO(SΦ)₂(S₂CNEt₂)]- contains a single oxo ligand coordinating to a molybdenum(IV) and the geometry around Mo(IV) atom is a distorted square pyramid. Interestingly, the solvate molecule isopropanol of 1b is linked to oxo group by a hydrogen-bond of 1.928Å, leading to the increase of Mo?O bond distance (1.718Å). Mo—S distances are 2.44 and 2.39Å. The electrochemical behavior of 1 was discussed also.     

Neue Synthese von (−)-(R)-Cembren A,Synthese von (+)-(R)-Cembrenen und (+)-(S)-Cembren

Novel Synthesis of (?)-(R)-Cembrene A, Synthesis of (+)-(R)-Cembrenene and (+)-(S)-Cembrene A novel synthesis of (?)-(R)-cembrene A ((?)- 3 ) was developed using the Sharpless epoxidation for the introduction of the chiral center. Furthermore, the synthesis of (+)-(R)-cembrenene ((+)- 4 ) showed that this cembranoid must have the (R)-configuration and not, as previously reported, the (S)-configuration. Selective hydrogenation of (+)- 4 afforded (+)-(S)-cenibrene ((+)- 5 ).     

Stereochemische Korrelationen zwischen (2R,4′R,8′R)-α-Tocopherol, (25S,26)-Dihydroxycholecalciferol, (–)-(1S,5R)-Frontalin und (–)-(R)-Linalol

Stereochemical Correlations between (2R,4′R,8′R)-α-Tocopherol, (25S,26)-Dihydroxycholecalciferol, (–)-(1S,5R)-Frontalin and (–)-(R)-Linalol The optically active C₅- and C₄-building units 1 and 2 with their hydroxy group at a asymmetric C-atom were transformed to (–)-(1S,5R)-Frontalin ( 7 ) and (–)-(3R)-Linalol ( 8 ) respectively; 1 and 2 had been used earlier in the preparation of the chroman part of (2R,4′R,8′R)-α-Tocopherol ( 6a , vitamin E), and for introduction of the side chain in (25S,26)-Dihydroxycholecalciferol ((25S)- 4 ), a natural metabolite of Vitamin D₃. The stereochemical correlations resulting from these converions fit into a coherent picture with those correlations already known from literature and they confirm our earlier stereochemical assignments. A stereochemical assignment concerning the C(25)-epimers of 25,26-Dihydroxycholecalciferol that was in contrast to our findings and that initiated the conversion of 1 and 2 to 7 resp. 8 for additional stereochemical correlations has been corrected in the meantime by the authors [26].     

Synthesis,Crystal Structure,and Magnetic Properties of (2,2′‐dipyridylamine)(X−) Copper(II) Complexes (X−: Cyanate,Dicyanamide, Acetate,Thiocyanato)

The synthesis, structure, and magnetic properties of four 2,2′‐dipyridylamine ligand (abbreviated as Hdpa) containing copper(II) complexes. There is one binuclear compound, which is [Cu₂(μ_1,1‐NCO)₂(NCO)₂(Hdpa)₂] ( 1 ), and three mononuclear compounds, which are [Cu{N(CN)₂}₂(Hdpa)₂] ( 2 ), [Cu(CH₃CO₂)(Hdpa)₂·N(CN)₂] ( 3 ), and [Cu(NCS)(Acac)] ( 4 ). Compounds 1 and 4 crystallize in the monoclinic system, space group P2(1)/c and Z = 4, with a = 8.2465(6) Å, b = 9.3059(7) Å, c = 16.0817(12) Å, β = 91.090(1)°, and V = 1233.90(16) ų for 1 and a = 7.6766(6) Å, b = 21.888(3) Å, c = 10.4678(12) Å, β = 90.301(2)°, and V= 1758.8(4) ų for 4 . Compounds 2 and 3 crystallize in the triclinic system, space group P‐1 and Z = 1, with a = 8.1140(3) Å, b = 8.2470(3) Å, c = 9.3120(4) Å, β = 102.2370(10)°, and V = 592.63(4) ų for 2 and a = 7.4780(2) Å, b = 12.5700(3) Å, c = 13.0450(3) Å, β = 96.351(2)°, and V = 1211.17(5) ų for 3 . Complex ( 1 ), the magnetic data was fitted by the Bleaney‐Bowers equation (1). A very good fit was derived with J = 23.96, Θ = ?1.5 (g = 1.97). Complex ( 1 ) shows the ferromagnetism. Complexes ( 2 ), ( 3 ) and ( 4 ) of have the it is the typical paramagnetic behavior of unpaired electrons. Under a low temperature around 25 K, complexes ( 2 ) and ( 3 ) show weak ferromagnetic behavior. They are the cause of hydrogen bonds.     

Synthesis of (+)-(S)-Streptenol A and Biomimetic Synthesis of (2R,4S)- and (2S,4S)-2-(Pent-3-enyl)piperidin-4-ol

(+)-(S)-Streptenol A is synthesized by coupling a 1,3-dithiane with an optically pure epoxide. The absolute configuration of (+)-(S)-streptenol A is thereby correlated with that of (S)-malic acid. Stereoselective reduction of an oxime that could easily be prepared from streptenol A gave the (3S,5R)- and (3S,5S)-aminostreptenols, and after cyclization, configurationally pure 2,4-functionalized piperidine alkaloids.     

Synthesis of the Enantiomerically Enriched Macrocyclic Lactones (+)-(S)- and (−)-(R)-Phoracantholide I and (+)-(S)-Tetradecan-13-olide

Synthesis of two naturally occurring macrocyclic lactones is described. (?)-(R)-Phoracantholide I ((?)- 1 ; Scheme 2) was synthesized by asymmetric and chemoselective reduction of the side-chain C?O group of (?)4-(1-nitro-2-oxocyclohexyl)butan-2-one ((?)- 6 ) with (R)-Alpine-Hydride (47% ee). It was shown that the formation of only one diastereoisomer of the hemiacetal 5 , by methylation with (i-PrO)₂TiMe₂ of ketoaldehyde (?)- 2 is thermodynamically controlled. (+)-(S)-Tetradecan-13-olide ((+)- 10 ) was obtained by reduction of diketone (±)- 11 with optically active borohydrides followed by denitration (Scheme 3).     

Le (−)-(2S)-2-Hydroxyhexanedioate de diéthyle,nouveau bloc chiral pour la synthèse énantiospécifique

The (?)-(2S)-Diethyl 2-Hydroxyhexanedioate, a New Chiral Building Block for Enantioselective Synthesis (?)-(2S)-Diethyl 2-hydroxyhexanedioate ((2S)-3) has been obtained by enantioselective reduction of diethyl 2-oxohexanedioate ( 1 ) with baker's yeast. The key intermediate (?)-(5S)-ethyl 5,6-dihydroxyhexanoate ((5S)- 5 ) is proved to be a useful synthon for the synthesis of chiral δ-lactones and a precursor of leukotriene LTB₄ ((5S)- 13 ).     

The Unprecedented Tetrakis‐(disulfato)‐silicate Anion [Si(S2O7)4]4−, its Germanium Congener [Ge(S2O7)4]4−, and the Tris‐(disulfato)‐metallates [M(S2O7)3]2− (M=Si,Ge, Ti), Stabilized by Divalent Counter Cations B2+ (B=Sr,Ba, Pb)

The reaction of oleum (65 % SO₃) with the tetrachlorides of silicon, germanium, and titanium, respectively, led to the complex disulfates Sr₂[M(S₂O₇)₄] (M=Si, Ge), Ba[M(S₂O₇)₃] (M=Si, Ge, Ti) and Pb[M(S₂O₇)₃] (M=Ge, Ti) if strontium, barium, and lead were used as divalent counter cations. The strontium compounds exhibit the unique tetrakis‐(disulfato)‐metallate anions [M(S₂O₇)₄]^4? with the silicon and germanium atoms in octahedral coordination of two chelating and two monodentate disulfate groups. All of the other compounds display tris‐(disulfato)‐metallate anions [M(S₂O₇)₃]^2? with three chelating disulfate groups surrounding the M atoms. Thermoanalytical investigations on the germanium compounds Sr₂[Ge(S₂O₇)₄] and Ba[Ge(S₂O₇)₃] revealed their decomposition in multi‐step processes leading to a mixture of BSO₄ and BGe₄O₉ (B=Sr, Ba), while the thermal degradation of Pb[Ti(S₂O₇)₃] yields PbTiO₃. For selected examples, IR data are additionally presented.     

Synthese von optisch aktiven,natürlichen Carotinoiden und strukturell verwandten Naturprodukten. VIII. Synthese von (3S,3′S)-7,8,7′,8′-Tetradehydroastaxanthin und (3S,3′S)-7,8-Didehydroastaxanthin (Asterinsäure)

Synthesis of Optically Active Natural Carotenoids and Structurally Related Compounds. VIII. Synthesis of (3S,3′S)-7,8,7′,8′-Tetradehydroastaxanthin and (3S,3′S)-7,8-Didehydroastaxanthin (Asterinic Acid) The synthesis of all-trans-(3S,3′S)-3,3′-dihydroxy-7,8, 7′,8′-tetradehydro-β, β-carotene-4,4′-dione ( 1 ), of all-trans-(3S,3′S)-3,3′-dihydroxy-7, 8-didehydro-β,β-carotene-4,4′-dione ( 2 ) (asterinic acid = mixture of 1 and 2 ), and of their 9,9′-di-cis- and 9-cis-isomers is reported starting from (4′S)(2E)-5-(4′-hydroxy-2′, 6′,6′-trimethyl-3′-oxo-l′-cyclohexenyl)-3-methyl-2-penten-4-ynal ( 8 ). The absolute configuration (3S,3′S) for both components 1 and 2 of asterinic acid ex Asterias rubens is confirmed on the basis of spectroscopic and direct comparison.     

Enantiomers of a selective gelatinase inhibitor: (R)‐ and (S)‐2‐[(4‐phenoxyphenyl)sulfonylmethyl]thiirane

The compound 2‐[(4‐phenoxyphenyl)sulfonylmethyl]thiirane, C₁₅H₁₄O₃S₂, a selective gelatinase inhibitor, was synthesized and structurally characterized. Two crystals were analyzed, one each for the R and S enantiomers, and the results were compared with the previously reported structure of the racemate. The enantiomerically pure compounds both crystallize with Z′ = 2 in the space group P2₁, while the racemic mixture crystallizes with Z′ = 1 in the space group P2₁/c, with disorder in the position of the thiirane group. This disorder accommodates both molecules for each of the enantiomerically pure crystals, showing good overlap of the molecules of the pure enantiomorphs with the components of the centrosymmetric structure.     

(E,E)-1,1′-[1,2-Bis(4-chlorophenyl)ethane-1,2-diyl]bis(phenyldiazene) revisited: threefold configurational disorder of (S,S), (R,R) and (S,R) isomers,a detailed critique

Crystal structures described as concomitant triclinic ( I ) and monoclinic ( II ) polymorphs of meso-(E,E)-1,1′-[1,2-bis(4-chlorophenyl)ethane-1,2-diyl]bis(phenyldiazene) [Mohamed et al. (2016). Acta Cryst. C 72 , 57–62] have been re-investigated. The published model for II was distorted due to forcing the symmetry of space group C2/c on an incomplete structure model. It is shown here to be a likely three-component superposition of S,S and R,R enantiomers with a lesser amount of the meso form. A detailed analysis of how the improbable distortion in the published model aroused suspicion and the subsequent construction of undistorted chemically and crystallographically plausible alternatives having the symmetry of Cc and C2/c is presented. For the sake of completeness, an improved model for the triclinic P structure of the meso isomer I , revised to include a minor disorder component, is also given.     

Vanadium(IV) dimer complexes containing [V(o-C6H4OS)3]2− fragment and caged sodium ions

Tris[o-mercaptophenolato]vanadium(IV) dimer complexes (A)₂[V(mp)₃NaLL']₂ (A = Ph₄P₊, H₂mp = o-mercaptophenol, L = MeCN, L'=EtOH, (1); L' = MeOH, (2)) were prepared by the reaction of anhydrous VC1₃, and Na₂mp in the molar ratio 1:3. Complex (3) (A = Et₄N⁺, L=L' = MeOH) was prepared by the reaction of VC1₃, Na₂mp and Li₂S in the molar ratio 1:2:1. The complexes were characterized by X-ray diffraction crystallography, infrared spectra, magnetic susceptibility, and cyclic voltammetric measurements. Complex 2 crystallizes in the triclinic space group P1 with a=12.813(6), b = 14.199(4), c = 12.790(5) Å, α = 112.72(2), β = 104.24(4). γ = 88.68(4)°, V = 2073.6 ų, and Z=1. The structure was refined to R=0.058. Complex 3 crystallizes in the mono-clinic space group P2₁/n with a=12.359(3), b=17.452(6), c=14.829(13) Å, βequals;96.51(5)°, V=3177.8 ų, and Z=2. The final R factor is 0.067. Both of the anions of 2 and 3 contain two [V(mp)₃]^2? fragments linked by sodium ions through the μ₃-O bridges with a crystallographic center of symmetry. The V(IV) atom is in a coordination environment intermediate between a trigonal prism and an ideal octahedron.