8-[(2-Hy­droxy­phen­yl)imino]-3,5a,9-trimethyl-3a,4,5,5a,8,9b-hexa­hydro­naphtho­[1,2-b]furan-2(3H)-one

Sammer Yousuf; Syed M Younas; Nida Ambreen; Khalid M Khan; Ghulam A Miana

doi:10.1107/S1600536812027146

. 2012 Jun 20;68(Pt 7):o2158. doi: 10.1107/S1600536812027146

8-[(2-Hydroxyphenyl)imino]-3,5a,9-trimethyl-3a,4,5,5a,8,9b-hexahydronaphtho[1,2-b]furan-2(3H)-one

Sammer Yousuf ^a,^*, Syed M Younas ^b, Nida Ambreen ^a, Khalid M Khan ^a, Ghulam A Miana ^c

PMCID: PMC3393965 PMID: 22798830

Abstract

The title compound, C₂₁H₂₃NO₃, is a phenylimine derivative of the well known anthelmintic agent α-santonin. The trans-fused cyclohexane and γ-lactone rings of the α-santonin ring system adopt chair and envelope conformations, respectively, whereas the hexadiene ring is approximately planar [maximum deviation = 0.029 (4) Å] and forms a dihedral angle of 62.30 (11)° with the benzene ring. An intramolecular O—H⋯N hydrogen bond is observed.

Related literature

For the isolation and anthelmintic use of α-santonin, see: Miana & Al-Lohedan (1986 ▶). For the crystal structure and stereochemistry of α-santonin, see: White & Sim (1975 ▶); Coggon & Sim (1969 ▶). For the crystal structure of a related compound, see: Yousuf et al. (2012 ▶).

Experimental

Crystal data

C₂₁H₂₃NO₃
M _r = 337.40
Orthorhombic,
a = 8.6000 (9) Å
b = 10.7458 (11) Å
c = 19.729 (2) Å
V = 1823.2 (3) Å³
Z = 4
Mo Kα radiation
μ = 0.08 mm⁻¹
T = 273 K
0.54 × 0.14 × 0.04 mm

Data collection

Bruker SMART APEX CCD area-detector diffractometer
Absorption correction: multi-scan (SADABS; Bruker, 2000 ▶) T _min = 0.957, T _max = 0.997
10874 measured reflections
1955 independent reflections
1385 reflections with I > 2σ(I)
R _int = 0.055

Refinement

R[F ² > 2σ(F ²)] = 0.041
wR(F ²) = 0.101
S = 1.04
1955 reflections
228 parameters
H-atom parameters constrained
Δρ_max = 0.14 e Å⁻³
Δρ_min = −0.13 e Å⁻³

Data collection: SMART (Bruker, 2000 ▶); cell refinement: SAINT (Bruker, 2000 ▶); data reduction: SAINT; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008 ▶); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008 ▶); molecular graphics: SHELXTL (Sheldrick, 2008 ▶); software used to prepare material for publication: SHELXTL, PARST (Nardelli, 1995 ▶) and PLATON (Spek, 2009 ▶).

Supplementary Material

Crystal structure: contains datablock(s) global, I. DOI: 10.1107/S1600536812027146/rz2770sup1.cif

e-68-o2158-sup1.cif^{(21.6KB, cif)}

Structure factors: contains datablock(s) I. DOI: 10.1107/S1600536812027146/rz2770Isup2.hkl

e-68-o2158-Isup2.hkl^{(96.2KB, hkl)}

Supplementary material file. DOI: 10.1107/S1600536812027146/rz2770Isup3.cml

Additional supplementary materials: crystallographic information; 3D view; checkCIF report

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

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
O3—H3A⋯N1	0.82	2.28	2.747 (4)	116

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Acknowledgments

The authors gratefully acknowledge the Pakistan Academy of Sciences for funding Project Reference No. 5–9/PAS/1335 entitled "Biology-Oriented Syntheses (BIOS) Based Synthesis of Libraries of Santonin".

supplementary crystallographic information

Comment

α-Santonin was isolated from Artemisia santonica (Miana & Al-Lohedan, 1986) and widely used in the past as an anthelmintic drug to expels parasitic worms (helminths) from the body, by either killing or stunning them. The title compound was prepared as a part of our ongoing reaserch to synthesize bioactive derivatives of α-santonin via biology oriented synthesis (BIOS). The title compound is an analogue of our previously reported compound 3,5a,9-trimethyl-3a,5,5a,9b-tetrahydronaphtho[1,2-b]furan-2,8(3H,4H)-dione-8-(N-phenylhydrazone), with the difference that the phenylhydrazine moiety is replaced by a 2-hydroxyphenylimine group (C16–C21) attached to the α-santonin ring system (O1–O2/C1–C15). The cyclohexadiene ring (C6–C11) is almost planar with a maximum deviation from the least square plane of 0.029 (3) Å for atom C7 and forms a dihedral angle of 62.30 (11)° with the phenyl ring. The cyclohexane ring (C3–C6/C11–C12) adopts a chair conformation [Q = 0.594 (4) Å, θ = 8.2 (4)° and φ = 304 (2)°] and is trans fused to the γ-lactone ring (O1/C1–C3/C12) which adopts an envelope conformation with atom C3 0.228 (3) Å out of the plane formed by the rest of the ring atoms. The two methyl substituents at atoms C6 and C2 exist in axial and pseudo equatorial orientations, respectively (Fig. 1). The bond dimensions are similar to those found in the structurally related compounds (Yousuf et al., 2012; White & Sim, 1975; Coggon & Sim, 1969). An intramolecular O—H···N hydrogen bond is present (Table 1). In the crystal, molecules are arranged into layers parallel to the ab plane only by van der Waals forces (Fig. 2).

Experimental

In a 100 ml round bottomed flask toluene (25 ml) and α-santonin (400 mg, 1.6 mmol) were taken, then 2-amino phenol (11.2 mmol) was added with continuous stirring. The reaction mixture was refluxed and monitored by TLC. After completion of reaction (24 h), the mixture was cooled and extracted with water. The organic layer was dried over Na₂SO₄, filtered and the solvent evaporated under vacuum in a rotary evaporator. The crude product was chromatographed on a silica gel column using n-hexane:ethyl acetate (7:3 v/v) as mobile phase to obtain yellow crystals of title compound in 85% yield.