(2S,4′R,5′R)-(E)-tert-Butyl 2-acetyl-2-(2-oxo-5-phenyl-1,3-dioxolan-4-ylmeth­yl)-5-phenyl­pent-4-enoate

David J Fox; Daniel Sejer Pedersen; Stuart Warren

doi:10.1107/S1600536808002651

. 2008 Jan 30;64(Pt 2):o530. doi: 10.1107/S1600536808002651

(2S,4′R,5′R)-(E)-tert-Butyl 2-acetyl-2-(2-oxo-5-phenyl-1,3-dioxolan-4-ylmethyl)-5-phenylpent-4-enoate

David J Fox ^a,^*,^‡, Daniel Sejer Pedersen ^a,^§, Stuart Warren ^a

PMCID: PMC2960464 PMID: 21201549

Abstract

The title compound, C₂₇H₃₀O₆, was prepared by monodihydroxylation of the bis-olefin (E,E)-tert-butyl 2-acetyl-2-cinnamyl-5-phenylpent-4-enoate using standard Sharpless asymmetric dihydroxylation conditions, followed by treatment with 1,1′-carbonyl diimidazole. In the crystal structure, the phenyl rings form an intramolecular edge-to-face C—H⋯π contact with an interplanar angle of 56.4° and a H⋯centroid distance of 3.03 Å.

Related literature

For related literature, see: Fox et al. (2006 ▶); Kolb et al. (1994 ▶).

Experimental

Crystal data

C₂₇H₃₀O₆
M _r = 450.51
Orthorhombic,
a = 6.4707 (2) Å
b = 7.7258 (4) Å
c = 49.803 (3) Å
V = 2489.7 (2) Å³
Z = 4
Mo Kα radiation
μ = 0.08 mm⁻¹
T = 200 (2) K
0.37 × 0.25 × 0.05 mm

Data collection

Nonius KappaCCD diffractometer
Absorption correction: multi-scan (SORTAV; Blessing, 1995 ▶) T _min = 0.817, T _max = 0.996
4524 measured reflections
1806 independent reflections
1188 reflections with I > 2σ(I)
R _int = 0.070

Refinement

R[F ² > 2σ(F ²)] = 0.080
wR(F ²) = 0.256
S = 1.10
1806 reflections
274 parameters
1 restraint
H-atom parameters constrained
Δρ_max = 0.64 e Å⁻³
Δρ_min = −0.68 e Å⁻³

Data collection: COLLECT (Nonius, 1998 ▶); cell refinement: SCALEPACK (Otwinowski & Minor, 1997 ▶); data reduction: DENZO (Otwinowski & Minor, 1997 ▶) and SCALEPACK; program(s) used to solve structure: SIR92 (Altomare et al., 1994 ▶); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008 ▶); molecular graphics: SHELXTL (Sheldrick, 2008 ▶); software used to prepare material for publication: SHELXTL.

Supplementary Material

Crystal structure: contains datablocks global, I. DOI: 10.1107/S1600536808002651/hg2374sup1.cif

e-64-0o530-sup1.cif^{(22.9KB, cif)}

Structure factors: contains datablocks I. DOI: 10.1107/S1600536808002651/hg2374Isup2.hkl

e-64-0o530-Isup2.hkl^{(89KB, hkl)}

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

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

Cg is the centroid of the C7–C12 ring.

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
C19—H19A⋯Cg	0.95	3.03	3.757	135

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Acknowledgments

The authors are grateful to Dr John E. Davies (University of Cambridge) for collecting the X-ray data.

supplementary crystallographic information

Comment

Recently, we published a method for the synthesis of dihydrofurans containing a diphenylphosphinoyl group by intramolecular ring opening of cyclic carbonates (Fox et al., 2006). We are currently seeking to extend this methodology with other anion-stabilizing groups. In particular, we are interested in replacing the diphenylphosphinoyl group with a carboxylic ester. When we exposed (E,E)-tert-butyl 2-acetyl-2-cinnamyl-5-phenylpent-4-enoate to the standard Sharpless asymmetric dihydroxylation conditions (Kolb et al., 1994), followed by treatment with 1,1'-carbonyl diimidazole we obtained a significant amount (20%) of the title compound where only one olefin had been dihydroxylated.

Experimental

The synthetic procedure is summarized in Fig. 2. By a method analogous to that reported by Sharpless and co-workers (Kolb et al., 1994), tert-butyl ester 1 (3.0 g, 10.9 mmol; 5:1 mixture of 1 and 2) was dissolved in t-BuOH (100 ml) to give a clear solution. Water (100 ml) was added and the mixture was cooled to 278 K. A freshly made mixture of K₂OsO₄.2H₂O (1 mol %), K₃Fe(CN)₆ (3 equiv.), K₂CO₃ (3 equiv.), MeSO₂NH₂ (1 equiv.) and hydroquinidine 1,4-phthalazinediyl diether (denoted (DHQD)₂PHAL, 2 mol %) was added to the cooled solution in one portion and it was stirred vigorously for 24 h. Sodium sulfite (ca 10 equiv.) was added and the reaction allowed to warm to room temperature with vigorous stirring. The slurry was transferred to a separatory funnel with water (200 ml) and extracted with ethyl acetate (3 × 100 ml). The combined organic extracts were washed with aqueous sulfate buffer (100 ml), saturated aqueous NaHCO₃ (100 ml), dried (Na₂SO₄), filtered and evaporated under reduced pressure. The residue was dissolved in dichloromethane (100 ml) and 1,1'-carbonyldiimidazole (1.5 equiv.) was added to the stirred solution at room temperature. The reaction mixture was stirred until completion to give a complex mixture of products. Water (100 ml) was added and the mixture transferred to a separatory funnel with brine (100 ml) and extracted with dichloromethane (3 × 100 ml). The combined organic phases were dried (Na₂SO₄), filtered and the solvent removed in vacuo to give the crude product that was purified through a combination of crystallizations and column chromatography to give 4 (338 mg, 14%) as a clear gum (1:1 mixture of diastereoisomers) and the title compound (denoted 6 in Fig. 2, 112 mg, 14%) as colourless plates (a single diastereoisomer). m.p. (EtOAc, pentane) = 449–450 K.