Mohamed Amedjkouh, Jacques Grimaldi, Jean-Pierre Reboul and Didier Siri

electronic papers Acta Crystallographica Section C Crystal Structure Communications ISSN 0108-2701 Diethyl [(2RS,5RS)-5-isopropyl-2,3,3-trimethylpyrrolidin-2-yl]phosphonate Mohamed Amedjkouh, Jacques Grimaldi, Jean-Pierre Reboul and Didier Siri Copyright International Union of Crystallography This paper is published electronically. It meets the data-validation criteria for publication in Acta Crystallographica Section C. The submission has been checked by a Section C Co-editor though the text in the Comments section is the responsibility of the authors. Mohamed Amedjkouh et al. ffl C 14 H 30 NO 3 P

electronic papers Acta Crystallographica Section C Crystal Structure Communications ISSN 0108-2701 Diethyl [(2RS,5RS)-5-isopropyl-2,3,3- trimethylpyrrolidin-2-yl]phosphonate Mohamed Amedjkouh, a Jacques Grimaldi, b Jean-Pierre Reboul c and Didier Siri d * a Department of Organic Chemistry, GoÈteborg University, Kemig aêrden 3, S-41296 GoÈteborg, Sweden, b Structure et ReÂactivite des EspeÁces ParamagneÂtiques, UMR 6517-CNRS Universite d'aix-marseille I et III, Av. Esc. Normandie Niemen, Case 521, 13397 Marseille CEDEX 20, France, c Groupe d'enseignement et de Recherche en Chimie TheÂrapeutique, Organique et Physique, Faculte de Pharmacie, 27 Boulevard Jean-Moulin, 13385 Marseille CEDEX 5, France, and d Laboratoire de Chimie TheÂorique et de ModeÂlisation MoleÂculaire, UMR 6517-CNRS Universite d'aix-marseille I et III, Av. Esc. Normandie Niemen, Case 521, 13397 Marseille CEDEX 20, France Correspondence e-mail: siri@dexter.u-3mrs.fr Received 6 December 1999 Accepted 13 December 1999 Data validation number: IUC9900188 The cis or trans conformation of the title compound (C 14 H 30 NO 3 P) is dif cult to predict because of its dependancy on experimental conditions. X-ray analysis shows a trans stereochemistry of the methyl and isopropyl groups in positions with respect to the N atom. As a precursor for a new serie of pyrrolidinyl nitroxides, the title compound was obtained using our new procedure. The crystallographic conformation of the pyrrolidinyl ring is 3 T 4 [the puckering parameters (Cremer & Pople, 1975) are: q = 0.374 (3) A Ê and ' = 85.1 (5) ] as it is usually observed for this kind of molecules. The methyl and isopropyl moities borne by C 5 and C 6, respectively, are in trans positions. The diethoxyphosphoryl group occupies the axial position on C 5 [the angle between the bond CÐP and the normal of the ring mean plane is 14.3 (2) ]. The crystal packing is assumed by N1Ð H30O3(3/2 x, y-1/2, 3/2-z) hydrogen bond with H30O3 2.30 (3) A Ê and N1ÐH30O3(3/2 x, y-1/2, 3/2-z) 152 (3), and usual van der Waals interactions of which the shortest distance is C14H10(C8)(x-1/2, 1/2-y, z-1/2) 3.09 (19) A Ê. Experimental (5-Isopropyl-2,3,3-trimethylpyrrolidin-2-yl)diethylphosphonate was synthesized by reduction of the corresponding pyrroline (Amedjkouh et al., 1997, 2000) with sodium borohydride. Suitable colorless prisms for X-ray analysis were grown in pentane solution in the fridge or at room temperature by slow evaporation. Comment Nitroxide radicals are becoming an increasingly important aspect of chemical applications due to the enormous need of materials enjoying new or improved physical and chemical properties. After being used in ESR as spin probes (Zhdanov, 1992; Keana, 1984; Berliner, 1976), they have also been applied as contrast-enhancing agents for magnetic resonance imaging (Kuppusamy et al., 1995). Recently, stable nitroxide radicals found a successful application in the eld of Living Free Radical Polymerization (Hawker, 1997; Grimaldi et al., 1997). The concept of using stable free radicals, such as pyrrolidine derived from -phosphorylated nitroxides, has been extensively developed in our laboratory. These nitroxides are prepared by oxidation of the corresponding - phosphorylated pyrrolidines (Roubaud et al., 1994, 1996). However, mixtures of cis and trans isomers were obtained by using this method. Recently, we have reported the cyclization of -allenic aminophosphonates into -phosphorylated pyrrolines (Amedjkouh et al., 1997). Its reduction with NaBH 4 leads only to the cis isomer, thus a series of (2,3,5-alkylpyrrolidin-2-yl)diethylphosphonates was prepared. In the present paper, we report the structure of diethyl [(2RS,5RS)-5- isopropyl-2,3,3-trimethylpyrrolidin-2-yl]phosphonate, (I). Crystal data C 14 H 30 NO 3 P M r = 291.37 Monoclinic, P2 1 =n a = 9.552 (3) A Ê b = 11.853 (7) A Ê c = 15.615 (4) A Ê = 96.47 (2) V = 1757 (2) A Ê 3 Z =4 D x = 1.10 Mg m 3 Data collection Enraf±Nonius CAD-4 diffractometer /2 scans 3018 measured re ections 2744 independent re ections 1861 re ections with I > 3(I) R int = 0.030 Re nement Re nement on F R = 0.049 R = missing wr = 0.069 S = 1.167 1861 re ections 173 parameters D m = 1.11 (2) Mg m 3 D m measured by otation Mo K radiation Cell parameters from 25 re ections = 10±16 = 0.162 mm 1 T = 294 K Prism, colorless 0.50 0.40 0.30 mm max = 24.70 h = 10! 10 k =0! 13 l =0! 17 2 standard re ections frequency: 60 min intensity decay: 9.64% H atoms treated by a mixture of independent and constrained re nement w =4F o 2 /[ 2 (F o 2 ) + 0.0025F o 4 ] (/) max = 0.003 max = 0.37 e A Ê 3 min = 0.20 e A Ê 3 Acta Cryst. (2000). C56, e31±e32 Mohamed Amedjkouh et al. C 14 H 30 NO 3 P e31

electronic papers Table 1 Selected geometric parameters (A Ê, ). PÐO1 1.579 (2) PÐO2 1.578 (3) PÐO3 1.463 (2) PÐC2 1.827 (3) O1ÐC1 1.442 (5) O2ÐC7 1.469 (5) NÐC2 1.484 (4) NÐC5 1.474 (4) C1ÐC6 1.490 (6) C2ÐC3 1.566 (5) O1ÐPÐO2 101.7 (1) O1ÐPÐO3 115.4 (1) O1ÐPÐC2 103.0 (1) O2ÐPÐO3 112.4 (1) O2ÐPÐC2 106.2 (1) O3ÐPÐC2 116.5 (1) PÐO1ÐC1 121.4 (2) PÐO2ÐC7 121.1 (2) C2ÐNÐC5 110.5 (2) O1ÐC1ÐC6 108.5 (4) O2ÐC7ÐC8 110.1 (4) PÐC2ÐN 103.3 (2) PÐC2ÐC3 114.1 (2) PÐC2ÐC9 108.2 (2) NÐC2ÐC3 104.4 (2) Table 2 Hydrogen-bonding geometry (A Ê, ). C2ÐC9 1.529 (4) C3ÐC4 1.528 (4) C3ÐC10 1.537 (5) C4ÐC5 1.515 (4) C5ÐC12 1.528 (4) C7ÐC8 1.441 (6) C3ÐC11 1.533 (5) C12ÐC13 1.521 (5) C12ÐC14 1.529 (5) NÐC2ÐC9 110.3 (2) C3ÐC2ÐC9 115.8 (3) NÐC5ÐC4 104.6 (2) NÐC5ÐC12 111.6 (3) C4ÐC5ÐC12 114.3 (3) C5ÐC4ÐC3 105.4 (3) C2ÐC3ÐC4 100.9 (2) C2ÐC3ÐC10 114.7 (3) C2ÐC3ÐC11 110.2 (3) C4ÐC3ÐC10 112.8 (3) C4ÐC3ÐC11 109.2 (3) C10ÐC3ÐC11 108.8 (3) C5ÐC12ÐC13 111.2 (3) C5ÐC12ÐC14 110.8 (3) C13ÐC12ÐC14 111.2 (3) DÐHA DÐH HA DA DÐHA NÐH30O3 i 0.85 (4) 2.30 (3) 3.078 (4) 152 (3) Symmetry codes: (i) 3 2 x; y 1 2 ; 3 2 z. All the H atoms were theoretically located except for the H 30 atom borne by the N atom, which was re ned. Data collection: CAD-4 Software (Enraf±Nonius, 1989); cell re nement: CAD-4 Software; data reduction: BEGIN SDP (Frenz, 1985); program(s) used to solve structure: MULTAN80 (Main et al., 1980); program(s) used to re ne structure: LSFM SDP (Frenz, 1985); software used to prepare material for publication: CIF VAX MolEN (Fair, 1990). References Amedjkouh, M., Faure, R., Hatem, J., Tordo, P. & Grimaldi, J. (1997). Phosphorus Sulfur Silicon, 126, 53±64. Amedjkouh, M., Hatem, J., Grimaldi, J. & Tordo, P. (2000). In preparation. Berliner, L. J. (1976). In Spin Labelling ± Theory and Applications I and II. New York: Academic Press. Cremer, D. & Pople, J. A. (1975). J. Am. Chem. Soc. 97, 1354±1358. Enraf±Nonius (1989). CAD-4 Software. Version 5.0. Enraf±Nonius, Delft, The Netherlands. Fair, C. K. (1990). MolEN. Enraf±Nonius, Delft, The Netherlands. Frenz, B. A. (1985). Enraf±Nonius SDP-Plus Structure Determination Package. Version 1.1. Enraf±Nonius, Delft, The Netherlands. Grimaldi, S., Finet, J. P., Zeghdaoui, A., Tordo, P., Benoit, D., Gnanou, Y., Fontanille, M., Nicol, P. & Pierson, J. F. (1997). Am. Chem. Soc. Polym. Prepr. 38, 651±652. Hawker, C. (1997). J. Acc. Chem. Res. 30, 373±382. Keana, J. F. W. (1984). In Spin Labelling in Pharmacology, edited by J. L. Holtzman, pp. 2±67. London: Academic Press. Kuppusamy, P., Chzan, M. & Sweier, J. L. (1995). J. Magn. Reson. Ser. B, 106, 122±130. Main, P., Fiske, S. J., Hull, S. E., Lessinger, L., Germain, G., DeClercq, J. P. & Woolfson, M. M. (1980). MULTAN80. University of York, England. Roubaud, V., Bliek, C., Lauricella, R., Vila, F., Siri, D. & Tordo, P. (1996). Phosphorus Sulfur Silicon, 112, 143±153. Roubaud, V., Le Moigne, F., Mercier, A. & Tordo, P. (1994). Phosphorus Sulfur Silicon, 86, 39±54. Zhdanov, R. I. (1992). In Bioactive Spin Labels I and II, edired by Heilderberg. Berlin: Springer-Verlag. e32 Mohamed Amedjkouh et al. C 14 H 30 NO 3 P Acta Cryst. (2000). C56, e31±e32

supporting information [doi:10.1107/s0108270199016303] Diethyl [(2RS,5RS)-5-isopropyl-2,3,3-trimethylpyrrolidin-2-yl]phosphonate Mohamed Amedjkouh, Jacques Grimaldi, Jean-Pierre Reboul and Didier Siri Computing details Data collection: CAD-4 Software (Enraf-Nonius, 1989); cell refinement: CAD-4 Software; data reduction: BEGIN SDP (Frenz, 1985); program(s) used to solve structure: MULTAN80 (Main et al., 1980); program(s) used to refine structure: LSFM SDP (Frenz, 1985); software used to prepare material for publication: CIF VAX MolEN (Fair, 1990). (I) Crystal data C 14 H 30 NO 3 P M r = 291.37 Monoclinic, P2 1 /n a = 9.552 (3) Å b = 11.853 (7) Å c = 15.615 (4) Å β = 96.47 (2) V = 1757 (2) Å 3 Z = 4 F(000) = 640 Data collection Enraf-Nonius CAD-4 diffractometer θ/2θ scans 3018 measured reflections 2744 independent reflections 1861 reflections with I > 3σ(I) R int = 0.030 Refinement Refinement on F Least-squares matrix: full R[F 2 > 2σ(F 2 )] = 0.049 wr(f 2 ) = 0.069 S = 1.17 1861 reflections 173 parameters D x = 1.10 Mg m 3 D m = 1.11 (2) Mg m 3 D m measured by flotation Mo Kα radiation, λ = 0.71073 Å Cell parameters from 25 reflections θ = 10 16 µ = 0.16 mm 1 T = 294 K Prism, colorless 0.50 0.40 0.30 mm θ max = 24.7, θ min = 2.2 h = 10 10 k = 0 13 l = 0 17 2 standard reflections every 60 min intensity decay: 9.6% 0 restraints H atoms treated by a mixture of independent and constrained refinement w = 4F o2 /[σ 2 (F o2 ) + 0.0025F o4 ] (Δ/σ) max = 0.003 Δρ max = 0.37 e Å 3 Δρ min = 0.20 e Å 3 Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å 2 ) x y z U iso */U eq P 0.88259 (9) 0.11005 (7) 0.83161 (5) 0.0500 (2) sup-1

O1 1.0475 (2) 0.1212 (2) 0.8532 (1) 0.0657 (7) O2 0.8394 (2) 0.0554 (2) 0.9170 (1) 0.0685 (7) O3 0.8077 (2) 0.2156 (2) 0.8097 (2) 0.0648 (7) N 0.7149 (2) 0.0366 (2) 0.7492 (2) 0.0496 (7) C1 1.1089 (4) 0.1940 (4) 0.9214 (3) 0.082 (1) C2 0.8640 (3) 0.0011 (2) 0.7501 (2) 0.0481 (8) C3 0.8749 (3) 0.0415 (3) 0.6561 (2) 0.0533 (9) C4 0.7266 (3) 0.0885 (3) 0.6322 (2) 0.0545 (9) C5 0.6292 (3) 0.0080 (3) 0.6722 (2) 0.0488 (8) C6 1.2599 (4) 0.2126 (4) 0.9098 (3) 0.104 (2) C7 0.6958 (5) 0.0674 (4) 0.9410 (3) 0.094 (1) C8 0.6995 (6) 0.1201 (5) 1.0244 (3) 0.120 (2) C9 0.9628 (4) 0.0979 (3) 0.7811 (2) 0.067 (1) C10 0.9907 (4) 0.1298 (4) 0.6483 (2) 0.073 (1) C11 0.8983 (4) 0.0583 (4) 0.5970 (3) 0.082 (1) C12 0.4930 (3) 0.0621 (3) 0.6952 (2) 0.060 (1) C13 0.4058 (4) 0.0214 (4) 0.7407 (3) 0.083 (1) C14 0.4080 (4) 0.1110 (4) 0.6149 (3) 0.100 (2) H1 1.1022 0.1584 0.9765 0.1011* H2 1.0575 0.2635 0.9208 0.1011* H3 1.3028 0.2621 0.9531 0.1275* H4 1.3088 0.1446 0.9101 0.1275* H5 1.2641 0.2497 0.8544 0.1275* H6 0.6535 0.0059 0.9443 0.1140* H7 0.6394 0.1111 0.8995 0.1140* H8 0.6069 0.1276 1.0393 0.1477* H9 0.7549 0.0762 1.0655 0.1477* H10 0.7408 0.1931 1.0207 0.1477* H11 0.5966 0.0497 0.6322 0.0638* H12 0.7187 0.1626 0.6541 0.0697* H13 0.7046 0.0902 0.5708 0.0697* H14 0.9488 0.1179 0.8383 0.0828* H15 0.9447 0.1616 0.7444 0.0828* H16 1.0584 0.0748 0.7798 0.0828* H17 1.0684 0.0973 0.6267 0.0907* H18 0.9531 0.1894 0.6107 0.0907* H19 1.0186 0.1625 0.7039 0.0907* H20 0.8289 0.1142 0.6010 0.0999* H21 0.8944 0.0327 0.5387 0.0999* H22 0.9896 0.0903 0.6132 0.0999* H23 0.5186 0.1222 0.7341 0.0754* H24 0.3209 0.0156 0.7547 0.1036* H25 0.3800 0.0836 0.7048 0.1036* H26 0.4570 0.0460 0.7930 0.1036* H27 0.3234 0.1440 0.6304 0.1256* H28 0.4617 0.1660 0.5897 0.1256* H29 0.3838 0.0517 0.5744 0.1256* H30 0.711 (3) 0.108 (3) 0.752 (2) 0.0507* sup-2

Atomic displacement parameters (Å 2 ) U 11 U 22 U 33 U 12 U 13 U 23 P 0.0492 (4) 0.0440 (4) 0.0561 (4) 0.0006 (4) 0.0022 (4) 0.0000 (4) O1 0.050 (1) 0.069 (1) 0.076 (1) 0.006 (1) 0.004 (1) 0.015 (1) O2 0.067 (1) 0.082 (2) 0.056 (1) 0.002 (1) 0.005 (1) 0.007 (1) O3 0.072 (1) 0.043 (1) 0.078 (1) 0.010 (1) 0.005 (1) 0.002 (1) N 0.046 (1) 0.042 (1) 0.061 (1) 0.005 (1) 0.006 (1) 0.006 (1) C1 0.070 (2) 0.080 (3) 0.091 (3) 0.006 (2) 0.011 (2) 0.022 (2) C2 0.040 (1) 0.041 (2) 0.063 (2) 0.002 (1) 0.006 (1) 0.000 (2) C3 0.048 (2) 0.056 (2) 0.058 (2) 0.004 (2) 0.014 (1) 0.003 (2) C4 0.050 (2) 0.062 (2) 0.051 (2) 0.004 (2) 0.001 (1) 0.007 (2) C5 0.044 (2) 0.049 (2) 0.053 (2) 0.004 (1) 0.003 (1) 0.000 (2) C6 0.070 (3) 0.091 (3) 0.144 (4) 0.016 (2) 0.021 (3) 0.027 (3) C7 0.087 (3) 0.127 (4) 0.069 (2) 0.010 (3) 0.012 (2) 0.003 (3) C8 0.144 (4) 0.133 (4) 0.086 (3) 0.001 (4) 0.023 (3) 0.023 (3) C9 0.059 (2) 0.048 (2) 0.092 (2) 0.014 (2) 0.002 (2) 0.000 (2) C10 0.056 (2) 0.085 (2) 0.081 (2) 0.015 (2) 0.018 (2) 0.007 (2) C11 0.079 (2) 0.090 (3) 0.079 (2) 0.004 (2) 0.024 (2) 0.022 (2) C12 0.045 (2) 0.065 (2) 0.069 (2) 0.001 (2) 0.003 (2) 0.002 (2) C13 0.055 (2) 0.093 (3) 0.107 (3) 0.010 (2) 0.028 (2) 0.001 (2) C14 0.056 (2) 0.129 (4) 0.112 (3) 0.012 (3) 0.008 (2) 0.033 (3) Geometric parameters (Å, º) P O1 1.579 (2) C2 C9 1.529 (4) P O2 1.578 (3) C3 C4 1.528 (4) P O3 1.463 (2) C3 C10 1.537 (5) P C2 1.827 (3) C4 C5 1.515 (4) O1 C1 1.442 (5) C5 C12 1.528 (4) O2 C7 1.469 (5) C7 C8 1.441 (6) N C2 1.484 (4) C3 C11 1.533 (5) N C5 1.474 (4) C12 C13 1.521 (5) C1 C6 1.490 (6) C12 C14 1.529 (5) C2 C3 1.566 (5) O1 P O2 101.7 (1) N C2 C9 110.3 (2) O1 P O3 115.4 (1) C3 C2 C9 115.8 (3) O1 P C2 103.0 (1) N C5 C4 104.6 (2) O2 P O3 112.4 (1) N C5 C12 111.6 (3) O2 P C2 106.2 (1) C4 C5 C12 114.3 (3) O3 P C2 116.5 (1) C5 C4 C3 105.4 (3) P O1 C1 121.4 (2) C2 C3 C4 100.9 (2) P O2 C7 121.1 (2) C2 C3 C10 114.7 (3) C2 N C5 110.5 (2) C2 C3 C11 110.2 (3) O1 C1 C6 108.5 (4) C4 C3 C10 112.8 (3) O2 C7 C8 110.1 (4) C4 C3 C11 109.2 (3) P C2 N 103.3 (2) C10 C3 C11 108.8 (3) sup-3

P C2 C3 114.1 (2) C5 C12 C13 111.2 (3) P C2 C9 108.2 (2) C5 C12 C14 110.8 (3) N C2 C3 104.4 (2) C13 C12 C14 111.2 (3) Hydrogen-bond geometry (Å, º) D H A D H H A D A D H A N H30 O3 i 0.85 (4) 2.30 (3) 3.078 (4) 152 (3) Symmetry code: (i) x+3/2, y 1/2, z+3/2. sup-4