(5S,6S)-4,5-Dimethyl-3-methyl­acryloyl-6-phenyl-1,3,4-oxadiazinan-2-one

Stanley A Knott; Shawn R Hitchcock; Gregory M Ferrence

doi:10.1107/S1600536808013986

. 2008 May 17;64(Pt 6):o1101. doi: 10.1107/S1600536808013986

(5S,6S)-4,5-Dimethyl-3-methylacryloyl-6-phenyl-1,3,4-oxadiazinan-2-one

Stanley A Knott ^a, Shawn R Hitchcock ^a, Gregory M Ferrence ^a,^*

PMCID: PMC2961593 PMID: 21202615

Abstract

The title compound, C₁₅H₁₈N₂O₃, is an example of an oxadiazinan-2-one with significant interaction between the N₃-acyl and N₄-methyl groups. These steric interactions result in a large torsion angle between the two carbonyl groups, not present with acyl substituents with less steric demand.

Related literature

For related literature, see: Bruno et al. 2004 ▶; Burgeson et al. (2004 ▶); Casper et al. (2002a ▶,b ▶); Ferrence et al. (2003 ▶); Hitchcock et al. (2001 ▶, 2004 ▶); Szczepura et al. (2004 ▶); Trepanier et al. (1968 ▶).

Experimental

Crystal data

C₁₅H₁₈N₂O₃
M _r = 274.31
Orthorhombic,
a = 8.7962 (6) Å
b = 9.7797 (6) Å
c = 16.6782 (11) Å
V = 1434.73 (16) Å³
Z = 4
Mo Kα radiation
μ = 0.09 mm⁻¹
T = 193 (2) K
0.46 × 0.38 × 0.21 mm

Data collection

Bruker P4/R4/SMART 1000 CCD diffractometer
Absorption correction: multi-scan (SADABS in SAINT-Plus; Bruker, 2003 ▶) T _min = 0.865, T _max = 0.982
9610 measured reflections
1702 independent reflections
1593 reflections with I > 2σ(I)
R _int = 0.032

Refinement

R[F ² > 2σ(F ²)] = 0.032
wR(F ²) = 0.080
S = 1.07
1702 reflections
181 parameters
H-atom parameters constrained
Δρ_max = 0.15 e Å⁻³
Δρ_min = −0.13 e Å⁻³

Data collection: SMART (Bruker, 2003 ▶); cell refinement: SAINT-Plus (Bruker, 2003 ▶); data reduction: SAINT-Plus; program(s) used to solve structure: SIR2004 (Burla et al., 2005 ▶); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008 ▶); molecular graphics: ORTEP-3 for Windows (Farrugia, 1997 ▶); software used to prepare material for publication: WinGX (Farrugia, 1999 ▶) and publCIF (Westrip, 2008 ▶).

Supplementary Material

Crystal structure: contains datablocks global, I. DOI: 10.1107/S1600536808013986/zl2116sup1.cif

e-64-o1101-sup1.cif^{(17.8KB, cif)}

Structure factors: contains datablocks I. DOI: 10.1107/S1600536808013986/zl2116Isup2.hkl

e-64-o1101-Isup2.hkl^{(82.1KB, hkl)}

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

Enhanced figure: interactive version of Fig. 2

Acknowledgments

This material is based upon work supported by the US National Science Foundation (CHE-0348158) (to GMF) and the American Chemical Society Petroleum Research Fund (to SRH & GMF). GMF thanks Robert McDonald and Michael Ferguson, X-ray Crystallography Laboratory, Department of Chemistry, University of Alberta for the data collection.

supplementary crystallographic information

Comment

In recent years, the synthesis of varying oxadiazinanones has led to chiral auxiliaries used in aldol addition reactions. The fundamental heterocyclic structure of related 1,3,4-oxadiazinan-2-one compounds has been known for nearly forty years (Trepanier et al., 1968); however, it has not been until recent years that more detailed conformational studies have been performed on species containing an N₃-acyl substituent (Hitchcock et al., 2001; Casper et al., 2002a). The influence of the N₃-acyl substituent is of significant importance in these studies. When the N₃-acyl substituent is of low steric demand the two carbonyls found in the molecule are co-planar and point at one another. However, when the N₃-substituent is of high steric demand, repulsive steric interactions between the N₃-acyl substituent and the N₄-methyl group cause the two carbonyls to twist out of planarity. The molecule represented herein is an example of a structure in which the acyl substituent at the N₃ position has a high steric demand.

Herein we report the single-crystal X-ray structure of a vinyl-acylated pseudoephedrine-derived 1,3,4-oxadiazinan-2-one (I). Several structures for various N₃ substituted oxadiazananones have been published (Burgeson et al., 2004; Casper et al., 2002b; Ferrence et al., 2003; Hitchcock et al., 2001, 2004). Also, a compound unsubstituted at the N₃ position has been synthesized (Szczepura et al., 2004). A Mogul (Bruno et al. 2004) geometry check showed all non-H bond angles, distances and torsions to be within typical ranges. The structures of previously reported acetyl, propionyl, and t-butylacetyl substituents at the N₃ position exhibit syn-parallel carbonyls. In contrast, in the title compound the 150.8 (2)° O16—C15—N3—C2 and 132.4 (3)° O20—C2—C15—O16 torsion angles are indicative of anti-parallel arrangement of the imide carbonyl groups. It appears likely that this arrangement helps to relieve steric congestion between the O16 carbonyl and the vinyl moiety while at the same time avoiding steric interactions between the N₄ methyl group and the vinyl CH₂ group. The O16—C15—C17—C18 torsion angle is 130.5 (2)°. The potential for steric interactions is further illustrated in the Jmol enhanced figure (Fig. 2).

Experimental

The title compound was prepared by acylation of pseudoephedrine derived 1,3,4-oxadiazinan-2-one using sodium hexamethyldisilazane and methylacrylolyl chloride (Casper et al., 2002a).