Crystal structure of (1S,2S,4S,5R)-2-hydroxymethyl-5-ethynyl-1-azabicyclo[ 2.2.2]octane, (HOCH2) (HC2)(C7H11N)

Wartchow, Rudolf; Schrake, Olaf; Braje, Wilfried M.; Hoffmann, H. M. R.

doi:10.1515/ncrs-1999-0268

Cited by 3 publications

(4 citation statements)

References 2 publications

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“…In the solid state the molecules of compound 1 are connected to helical chains by hydrogen bonds in a similar manner as found in compound 2 (see the figure in [8]) and in quinidine [2]. The chain direction in 1 is [100] and corresponds to the [010] direction in 2.…”

Section: Discussionmentioning

confidence: 83%

Crystal structure of (1S,2R,4S,5S)-5-ethynyl-2-hydroxymethyl-1-azabicyclo[2.2.2]octane, (HC2)(HOCH2)C7H11N)

Wartchow¹,

Frackenpohl²,

Hoffmann³

2001

Zeitschrift Für Kristallographie - New Crystal Structures

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Source of materialQuincoridine® [1] (2.0 g, 12 mmol) was dissolved in dry CCI4 (15 ml). Bromine (1.1 ml, 21.5 mmol) was added at 273 Κ. The reaction mixture was stirred for lh. After removal of the solvent in vacuo the resulting yellow solid was dissolved in CHCI3 (25 ml). Et3N (3.1 ml, 24 mmol) was added and the mixture was then stirred for 4h at RT. After work-up (CHCI3 and saturated aqueous solution NaHC03) the vinylic bromide (0.2 g, 0.81 mmol) was dissolved in THF (10 ml), followed by addition of powdered KOH (116 mg, 2.0 mmol) and aliquat 336® (0.73 ml, 0.16 mmol). The reaction mixture was heated at reflux for 7 h. Work-up (CHCI3 and saturated aqueous solution NaHCOs) and column chromatography (ethyl acetate / methanol 6:1) furnished the title compound which crystallized after 5 h at 273 K. The compound melts at 317 Κ and sublimes readily. DiscussionThe title compound 1 is derived from quinidine [2] via quincoridine® (QCD) [1,3,4] and is to be compared to the (lS,2S,4S,5S)-diastereomer 2 which is derived from quinine [5] via quincorine® (QCI) [1,3,4], The transformation of QCD and QCI to compounds 1 and 2, respectively, can formally be described as the replacement of the vinyl group by the ethynyl group (see scheme 1 in [6]). Compound 1 is called 10,11-didehydroquincoridine and compound 2 10,11-didehydro-quincorine [6]. In view of the high synthetic flexibility of alkynes we expect that 1 and 2 will become valuable homochiral building blocks, e.g. in asymmetric synthesis and in medicinal chemistry, similar to QCD and QCI [3,4,7]. The terminal alkynes 1 and 2 have the advantage of being solids at room temperature, while QCD and QCI are liquids. The crystal structure of 2 has already been reported inThe X-ray analysis of 1 (this work) shows that its crystal packing has the higher point group symmetry (222 instead of 2) but the lower density by about 2 %. In the solid state the molecules of compound 1 are connected to helical chains by hydrogen bonds in a similar manner as found in compound 2 (see the figure in [8]) and in quinidine [2]. The chain direction in 1 is [100] and corresponds to the [010] direction in 2. Substituted quinuclidines are often twisted [9]. The dihedral angles C2-N1-C4-C3, C6-N1-C4-C5 and C7-N1-C4-C8 are 10.9°, 9.7° and 9.1°, respectively, with an average of 9.9° for molecule 1 and 3.7°, 6.7°

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Section: Discussionmentioning

confidence: 83%

Crystal structure of (1S,2R,4S,5S)-5-ethynyl-2-hydroxymethyl-1-azabicyclo[2.2.2]octane, (HC2)(HOCH2)C7H11N)

Wartchow¹,

Frackenpohl²,

Hoffmann³

2001

Zeitschrift Für Kristallographie - New Crystal Structures

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“…Small torsion angles Φι (N1-C7-C6-C5) = 6.3° and Φ 2 (Ν 1-C8-C9-C5) = 2.4° suggest reduced conformational strain of the l-azabicyclo[3.2.2]nonane moiety compared with related l-azabicyclo[2.2.2]octanes which are strongly twisted to minimize eclipsing and ring strain [ 1 ]. The bridgehead nitrogen in the title compound is more flattened, with an expansion of bond angles, than in quincorine derivatives [8]. (1) 0(2) 4 a 0.3836 (4) …”

Section: Discussionmentioning

confidence: 95%

Crystal structure of (1S,2R,5R,6R)-2-methoxy-6-(16-nitrophenylethynyl)-1-azabicyclo[3.2.2]nonane, C17H20N2O3

Frackenpohl

Röper

Hoffmann

et al. 2000

Zeitschrift Für Kristallographie - New Crystal Structures

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C17H20N2O3, orthorhombic, P2\2\2\ (No. 19), a = 7.096(1) Ä, b= 11.671(1) k,c= 19.277(2) Ä, V= 1596.5 Ä 3 ,Z = 4, R gl (F) = 0.032, wRrefiF 2 ) = 0.040, T= 300 K.Source of material p-N02-Phenyl substituted 10,11-didehydroquincorine [1] was transformed into its corresponding C9-iodide via mesylation and Lil-mediated iodination. The resulting 2-iodomethyl-5-(16-nitrophenylethynyl)-l-azabicyclo[3.2.2]-nonane (500 mg, 1.26 mmol, 1 eq) was dissolved in abs. MeOH (6 ml). After being stirred for 5 min at room temperature under argon freshly prepared silver benzoate (318 mg, 1.39 mmol, 1.1 eq) was added. The reaction mixture was stirred for 16 h at 323 K, diluted with MeOH and filtered. The remaining precipitate was washed with MeOH, the combined solutions were concentrated in vacuo and the resulting solid was dissolved in CH2CI2. After addition of saturated aqueous NaHCOs, the aqueous layer was extracted with CH2CI2, and the combined organic layer dried (MgS04)

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“…The bond lengths and bond angles are comparable, within 3s, with those in QCD + cation and in quinine toluene solvate monohydrate 21 or didehydroquincorine. 22 As shown by the absolute value of the torsion angle C7-C8-C9-O12 (Table 4), the conforma- tion of QCI is different from that of quinine and resembles those of quincoridine and epi cinchonine. The conformation of the vinyl moiety with regard to the bond C10-C11 is very similar to that in QCD.…”

Section: Qcd + Cationmentioning

confidence: 96%

“…Comparison of the molecular conformation of QCI cation and its didehydro derivative (didehydroquincorine) 22 shows some divergences which may be the effect of different substituents at C3 and the nature of the environment in the crystal structures. Didehydro-QCI has very similar conformation to that of QCI cation with the exception of the fragment C3-C10-C11 which is approximately linear and the orientation of the -O12-H12.…”

Section: Qcd + Cationmentioning

confidence: 99%

Crystal and molecular structures of new enantiopure quinuclidines

2004

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X-ray crystal structure analysis was performed on single crystals of two diastereomeric enantiopure quinuclidines, (3R,8R)-3-vinyl-8-hydroxymethyl-quinuclidine (quincoridine, QCD) and (3R,8S)-3-vinyl-8-hydroxymethyl-quinuclidine (quincorine, QCI) as their salts with tartaric and p-toluenesulphonate anions, respectively. The molecules of these quinuclidine derivatives are considered here as fragments of the Cinchona alkaloids, quinidine and quinine. A comparison of the conformational features of QCD, QCI, and Cinchona alkaloids in the crystalline state shows that the molecular geometry of the title compounds is similar to that of threo-alkaloids (e.g., R,R isomer of epicinchonine) rather than to quinidine and quinine. The packing of the molecules in both structures is dominated by intermolecular hydrogen bonds.

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Crystal structure of (1S,2S,4S,5R)-2-hydroxymethyl-5-ethynyl-1-azabicyclo[ 2.2.2]octane, (HOCH2) (HC2)(C7H11N)

Cited by 3 publications

References 2 publications

Crystal structure of (1S,2R,4S,5S)-5-ethynyl-2-hydroxymethyl-1-azabicyclo[2.2.2]octane, (HC2)(HOCH2)C7H11N)

Crystal structure of (1S,2R,4S,5S)-5-ethynyl-2-hydroxymethyl-1-azabicyclo[2.2.2]octane, (HC2)(HOCH2)C7H11N)

Crystal structure of (1S,2R,5R,6R)-2-methoxy-6-(16-nitrophenylethynyl)-1-azabicyclo[3.2.2]nonane, C17H20N2O3

Crystal and molecular structures of new enantiopure quinuclidines

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