Crystal structure of N′-[(E)-(1S,3R)-(3-isopropyl-1-methyl-2-oxo­cyclo­pent­yl)methyl­idene]-4-methyl­benzene­sulfono­hydrazide

David Tymann; Dina Christina Dragon; Christopher Golz; Hans Preut; Carsten Strohmann; Martin Hiersemann

doi:10.1107/S2056989015020307

. 2015 Nov 4;71(Pt 12):o904–o905. doi: 10.1107/S2056989015020307

Crystal structure of N′-[(E)-(1S,3R)-(3-isopropyl-1-methyl-2-oxocyclopentyl)methylidene]-4-methylbenzenesulfonohydrazide

David Tymann ^a, Dina Christina Dragon ^a, Christopher Golz ^a, Hans Preut ^a,^*, Carsten Strohmann ^a, Martin Hiersemann ^a

PMCID: PMC4719872 PMID: 26870519

Abstract

The title compound, C₁₇H₂₄N₂O₃S, was synthesized in order to determine the relative configuration of the corresponding β-keto aldehyde. In the U-shaped molecule, the five-membered ring approximates an envelope, with the methylene C atom adjacent to the quaternary C atom being the flap, and the methyl and isopropyl substituents lying to the same side of the ring. The dihedral angles between the four nearly coplanar atoms of the five-membered ring and the flap and the aromatic ring are 35.74 (15) and 55.72 (9)°, respectively. The bond angles around the S atom are in the range from 103.26 (12) to 120.65 (14)°. In the crystal, molecules are linked via N—H⋯O hydrogen bonds, forming a chain along the a axis.

Keywords: crystal structure, hydrogen bonding, terpenoid synthesis

Related literature

For the synthesis of terpenoid-related buildings blocks, in particular cyclopentanoids, see: Helmboldt et al. (2006 ▸); Gille et al. (2011 ▸); Becker et al. (2013 ▸); Tymann et al. (2014 ▸). For the crystal structure of the corresponding trans-diastereomer, see: Tymann et al. (2015 ▸). For a review on cyclopentanoids by ring contraction, see: Silva (2002 ▸). For a solid-acid catalysed rearrangement of cyclic α,β-epoxy ketones, see: Elings et al. (2000 ▸). graphic file with name e-71-0o904-scheme1.jpg

Experimental

Crystal data

C₁₇H₂₄N₂O₃S
M _r = 336.44
Orthorhombic,
a = 9.4918 (7) Å
b = 13.2348 (12) Å
c = 14.6691 (12) Å
V = 1842.8 (3) Å³
Z = 4
Mo Kα radiation
μ = 0.19 mm⁻¹
T = 173 K
0.31 × 0.25 × 0.23 mm

Data collection

Oxford Diffraction Xcalibur Sapphire3 diffractometer
Absorption correction: multi-scan (CrysAlis RED; Oxford Diffraction, 2008 ▸) T _min = 0.98, T _max = 1.00
15093 measured reflections
4215 independent reflections
3526 reflections with I > 2σ(I)
R _int = 0.046

Refinement

R[F ² > 2σ(F ²)] = 0.042
wR(F ²) = 0.093
S = 1.05
4215 reflections
216 parameters
H atoms treated by a mixture of independent and constrained refinement
Δρ_max = 0.22 e Å⁻³
Δρ_min = −0.33 e Å⁻³
Absolute structure: Flack x determined using 1277 quotients [(I ⁺)-(I ^-)]/[(I ⁺)+(I ^-)] (Parsons & Flack, 2004 ▸)
Absolute structure parameter: −0.02 (4)

Data collection: CrysAlis CCD (Oxford Diffraction, 2008 ▸); cell refinement: CrysAlis CCD; data reduction: CrysAlis CCD; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008 ▸); program(s) used to refine structure: SHELXL2013 (Sheldrick, 2015 ▸); molecular graphics: SHELXTL-Plus (Sheldrick, 2008 ▸); software used to prepare material for publication: SHELXL97 (Sheldrick, 2008 ▸) and PLATON (Spek, 2009 ▸).

Supplementary Material

Crystal structure: contains datablock(s) I, 2887. DOI: 10.1107/S2056989015020307/tk5399sup1.cif

e-71-0o904-sup1.cif^{(520KB, cif)}

Structure factors: contains datablock(s) I. DOI: 10.1107/S2056989015020307/tk5399Isup2.hkl

e-71-0o904-Isup2.hkl^{(335.9KB, hkl)}

Click here for additional data file.^{(3.3KB, cml)}

Supporting information file. DOI: 10.1107/S2056989015020307/tk5399Isup3.cml

Click here for additional data file.^{(1.4MB, tif)}

. DOI: 10.1107/S2056989015020307/tk5399fig1.tif

The molecular structure of the title compound, showing the labelling of all non-H atoms. Displacement ellipsoids are shown at the 50% probability level.

CCDC reference: 1037859

Additional supporting information: crystallographic information; 3D view; checkCIF report

Table 1. Hydrogen-bond geometry (Å, °).

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
N1—H1N⋯O3ⁱ	0.86 (3)	2.00 (4)	2.836 (3)	164 (3)

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Symmetry code: (i) Inline graphic .

Acknowledgments

Financial support obtained from the Beilstein Institut is greatly acknowledged.

supplementary crystallographic information

S1. Comment

Prompted by our efforts in natural product synthesis, we seek access to cyclopentyl units. Herein, we chose a ring contraction strategy of a cyclic epoxy ketone. A Brønsted-acid promoted semi-pinacol rearrangement of trans-piperitone oxide afforded cis-3-isopropyl-1-methyl-2-oxocyclopentane-1-carbaldehyde (II) along with 2-hydroxypiperitone. A condensation of (II) with p-toulenesulfonyl hydrazide afforded the title compound, (I).

S2. Experimental

A sealable glass pressure tube was charged with a solution of cis-3-isopropyl-1-methyl-2-oxocyclopentane-1-carbaldehyde (II) (C₁₀H₁₆O₂, M = 168.23 g/mol, [α]_D²⁰ = -107.4 (c 0.059, CHCl₃), 40 mg, 0.238 mmol, 1.0 eq) and p-toluenesulfonyl hydrazide (C₇H₁₀N₂O₂S, M = 186.23 g/mol, 62 mg, 0.333 mmol, 1.4 eq) in methanol (3 ml, 12.6 ml/mmol). The tube was sealed with a Teflon screw cap and stirred for 75 min at ambient temperature. Next, the reaction mixture was concentrated in vacuo and loaded onto silica gel with CH₂Cl₂ for flash chromatography (cyclohexane/ethyl acetate 10/1) to deliver the title compound (I) (C₁₇H₂₄N₂O₃S, M = 336.45 g/mol, 56 mg, 0.166 mmol, 70%) as a white solid and as an apparent mixture of double bond isomers (ratio = 95:5). Subsequent recrystallization of (I) from n-pentane/Et₂O provided colourless crystals of the E-configured double bond isomer of (I). The ratio of isomers was determined by integration of the ¹H NMR signals at 0.35 p.p.m. (d, J = 6.9 Hz, 3H) and 0.47 p.p.m. (d, J = 6.9 Hz, 3H). Characterization data are reported for the major compound from the mixture of double bond isomers. R_f 0.41 (cyclohexane/ethyl acetate 2/1); m.p. 388–391 K; ¹H NMR (CDCl₃, 500 MHz) δ 0.47 (d, J = 6.9 Hz, 3H), 0.85 (d, J = 6.9 Hz, 3H), 1.16 (s, 3H), 1.48–1.59 (m, 2H), 1.82–1.95 (m, 2H), 2.11 (td, J = 9.4 Hz, J = 5.0 Hz, 1H), 2.42 (s, 3H), 2.49–2.53 (m, 1H), 6.88 (s, 1H), 7.30 (d, J = 8.0 Hz, 2H), 7.78 (d, J = 8.0 Hz, 2H), 7.89 (s, 1H). ¹³C NMR (CDCl₃, 126 MHz) δ 18.4 (CH₃), 20.8 (CH₃), 21.2 (CH₂), 21.5 (CH₃), 21.9 (CH₃), 27.8 (CH), 31.6 (CH₂), 53.8 (C), 54.7 (CH), 128.0 (2x CH), 129.6 (2x CH), 135.1 (C), 144.2 (C), 150.6 (CH), 219.1 (C). IR ν 3415 (w), 3126 (s), 2960 (s), 22870 (s), 1725 (s), 1600 (m), 1455 (s), 1360 (s), 1330 (m), 1170 (s), 1095 (m), 1050 (s), 940 (m) 820 (s); Anal. Calcd. for C₁₇H₂₄N₂O₃S: C, 60.7, H, 7.2, N, 8.3. Found: C, 60.6, H, 7.3, N, 8.3.