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Synlett 2004(9): 1489-1496  
DOI: 10.1055/s-2004-829536
LETTER
© Georg Thieme Verlag Stuttgart · New York

Direct Aminoalkylation of α-Branched Aldehydes with in situ Generated Glycine Cation Equivalents

Stefan Piper, Nikolaus Risch*
Department Chemie, Fakultät für Naturwissenschaften, Universität Paderborn, Warburger Straße 100, 33098 Paderborn, Germany
Fax: +49(5251)603245; e-Mail: nr@chemie.uni-paderborn.de;
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Publikationsverlauf

Received 14 January 2004
Publikationsdatum:
29. Juni 2004 (online)

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Abstract

The efficient synthesis of β-formyl-α-aminocarboxylates 4 by direct aminoalkylation of aldehydes with in situ generated ternary iminium salts from inexpensive starting materials is described. These compounds are easily transformed into α-amino-β,β-dialkyl-γ-butyrolactones 10 and α,α-dialkyl-β-dialkylamino-butane-1,4-­diols 11 and can be used as versatile building blocks.

Key words

β-formyl-α-aminocarboxylate - ternary iminium salts - 1,4-butanediols - Mannich bases - butyrolactones

5

Preparation of β-Formyl-α-aminocarboxylates 4a-m. Method A: All reactions were conducted under argon. To generate the iminium salt 3, a solution of ethyl glyoxylate aminal 2 4 (2.5 mmol) in anhyd CH2Cl2 (10 mL) was cooled to -80 °C. TiCl4 (2.5 mmol, 0.28 mL) was added in one portion under stirring. After a reaction time of 1 h at this temperature, the aldehyde 1 (2.5 mmol) was added. The temperature was then allowed to rise slowly to 20 °C. The mixture was quenched with HCl (6 N) and the aqueous layer was washed with Et2O several times. The aqueous layer was basified by the addition of aq sat. NaHCO3 solution and NaOH (2 N) to pH 10-12. The product was extracted with Et2O, the combined organic layers were dried (Na2SO4) and the solvent was removed in vacuo. The aminoalkylated aldehydes 4 were isolated as yellowish oily products without further purification. Analytical data of some representative synthesized compounds (* minor diastereoisomer):
2-Dibenzylamino-3,3-dimethyl-4-oxo-butyric Acid Ethyl Ester (4e): 1H NMR (200 MHz, CDCl3): δ = 1.08 (s, 3 H), 1.14 (s, 3 H), 1.43 (t, 3 H, J = 7.1 Hz), 3.68 (s, 1 H), (δA = 3.57, δB = 3.98, 4 H, J = 13.7 Hz), 4.25-4.44 (m, 2 H), 7.24-7.46 (m, 10 H), 9.35 (s, 1 H) ppm. 13C NMR (50 MHz, CDCl3): δ = 15.08, 20.39, 20.51 (q), 49.46 (s), 57.41, 60.98 (t), 66.17, 127.83, 128.82, 129.65 (d), 139.28, 170.99 (s), 205.02 (d) ppm. IR (neat): 3062, 3030, 2978, 2935, 2848, 1728, 1603, 1495, 1454, 1367, 1203, 1134, 1028, 970, 939, 748, 700 cm-1. MS (80 eV): m/z (%) = 353 (10) [M]+, 282 (100), 280 (26), 253 (49), 159 (47), 117 (20), 106 (32), 91 (50), 65 (11), 42 (9). (1-Formyl-cyclohexyl)-piperidin-1-yl-acetic Acid Ethyl Ester (4g): 1H NMR (200 MHz, CDCl3): δ = 1.28 (t, 3 H, J = 7.1 Hz), 1.32-1.64 (m, 14 H), 1.88-2.21 (m, 2 H), 2.28-2.42 (m, 2 H), 2.59-2.73 (m, 2 H), 3.22 (s, 1 H), 4.16 (dq, 2 H, J = 7.1 Hz, J = 1.7 Hz), 9.80 (s, 1 H) ppm. 13C NMR (50 MHz, CDCl3): δ = 14.96 (q), 22.82, 22.95, 24.49, 25.96, 27.02, 29.42, 30.10 (t), 52.65 (s), 53.88, 60.54 (t), 76.34 (d), 170.29 (s), 207.68 (d) ppm. IR (neat): 2933, 2854, 2810, 1726, 1452, 1389, 1369, 1333, 1178, 1151, 1117, 1097, 860, 750 cm-1. MS (80 eV): m/z (%) = 281 (23) [M]+, 251 (3), 207 (19), 170 (100), 133 (4), 96 (9), 55 (1), 41 (6).
2-(Benzyl-methyl-amino)-3-formyl-3-methyl-pentanoic Acid Ethyl Ester (4k): 1H NMR (200 MHz, CDCl3): δ = 0.80, 0.81* (t, 3 H, J = 7.6 Hz), 1.22, 1.28* (s, 3 H), 1.36*, 1.37 (t, 3 H, J = 7.1 Hz), 1.57-1.90 (m, 2 H), 2.33, 2.34* (s, 3 H), 3.63*, 3.65 (s, 1 H), (δA = 3.63, δB = 3.85, 2 H, J = 13.4 Hz), 4.26*, 4.27 (q, 2 H, J = 7.1 Hz), 7.18-7.44 (m, 5 H), 9.63, 9.74* (s, 1 H) ppm. 13C NMR (50 MHz, CDCl3): δ = 8.48, 8.58*, 15.01, 15.80, 16.65* (q), 27.28, 27.93* (t), 40.63, 40.87* (q), 52.90, 53.23* (s), 60.73, 60.82*, 61.58, 61.73* (t), 71.09*, 71.17, 127.55*, 127.60, 128.73, 129.00*, 129.06, 129.18* (d), 139.40, 139.67*, 170.40, 171.22* (s), 204.74, 206.32* (d) ppm. IR (neat): 2974, 2939, 2806, 1728, 1454, 1369, 1223, 1186, 1146, 1026, 741, 698 cm-1. MS (80 eV): m/z (%) = 291 (18) [M]+, 217 (18), 206 (100), 152 (2), 131 (5), 120 (10), 91 (9), 65 (2), 56 (3), 42 (20).
2-Dimethylamino-3-ethyl-3-formyl-heptanoic Acid Ethyl Ester (4l): 1H NMR (200 MHz, CDCl3): δ = 0.71*, 0.73 (t, 3 H, J = 7.6 Hz), 0.84 (t, 3 H, J = 6.8 Hz), 0.90-1.19 (m, 4 H), 1.24 (t, 3 H, J = 7.1 Hz), 1.40-1.77 (m, 4 H), 2.24*, 2.25 (s, 6 H), 3.28 (s, 1 H), 4.14*, 4.16 (q, 2 H, J = 7.1 Hz), 9.84*, 9.85 (s, 1 H) ppm. 13C NMR (50 MHz, CDCl3): δ = 7.78, 8.05*, 14.14, 14.33*, 14.87 (q), 21.11, 23.04*, 23.59, 23.70*, 25.47*, 25.66, 27.67*, 29.65 (t), 43.96, 44.00* (q), 54.72, 54.83* (s), 60.57 (t), 72.65, 72.72* (d), 170.23, 170.26* (s), 206.83*, 206.90 (d) ppm. IR (neat): 2960, 2939, 2873, 2788, 1724, 1460, 1381, 1186, 1151, 1097, 1032, 944, 867, 766 cm-1. MS (80 eV): m/z (%) = 257 (28) [M]+, 215 (2), 184 (6), 155 (4), 130 (100), 102 (8), 83 (2), 58 (17).

8

Preparation of β-Formyl-α-aminocarboxylates 4n-s and Hydrochlorides 7. Method B: The reactions were conducted under argon. To generate the iminium salt 6, a solution of ethyl glyoxylate aminal 5 6 (2.5 mmol) in anhyd CH2Cl2 (5 mL) was cooled to 0 °C. Acetyl chloride (2.5 mmol, 0.18 mL) was added in one portion under stirring. After stirring the mixture for 1 h at this temperature, the aldehyde 1 (2.5 mmol) was added and the temperature was allowed to rise to 20 °C. The solvent was removed in vacuo and the crude product was diluted with Et2O or EtOAc and filtered. Hydrochlorides 7 were isolated as colorless solids, dried in high vacuum and stored under argon. Hydrochloride 7 (2.0 mmol) was dissolved in CH2Cl2 (5 mL) and treated with cold aq sat. NaHCO3 solution. The organic layer was washed with water and dried (Na2SO4). The solvent was removed in vacuo to yield β-formyl-α-aminocarboxylates 4. Analytical data of some representative synthesized compounds:
1-(1-Ethoxycarbonyl-2-methyl-3-oxo-2-phenyl-propyl)-piperidinium Chloride (7o): 1H NMR (200 MHz, CDCl3): δ = 0.87 (t, 3 H, J = 7.1 Hz), 1.54-1.99 (q, 6 H), 2.32 (s, 3 H), 2.48-2.85 (m, 2 H), 3.04-3.26 (m, 2 H), 3.59-3.93 (m, 2 H), 4.80 (s, 1 H), 7.23-7.44 (m, 5 H), 9.44 (s, 1 H) ppm. 13C NMR (50 MHz, CDCl3): δ = 13.74, 14.88, 21.97, 22.59, 44.82 (q), 55.72 (s), 62.86 (t), 71.47, 128.61, 129.38, 129.49 (d), 132.98, 164.78 (s), 198.01 (d) ppm. IR (KBr): 2950, 2841, 2733, 2629, 2525, 1740, 1714, 1450, 1414, 1331, 1264, 1207, 1021, 700 cm-1. MS (70 eV): m/z (%) = 303(1) [M - HCl]+, 230 (3), 216 (9), 190 (29), 170 (35), 133 (38), 105 (100), 77 (25), 57 (12), 43 (23), 29 (45). 3-Methyl-4-oxo-3-phenyl-2-piperidin-1-yl-butyric Acid Ethyl Ester (4o): 1H NMR (200 MHz, CDCl3): δ = 1.13 (t, 3 H, J = 7.1 Hz), 1.32-1.58 (q, 6 H), 1.77 (s, 3 H), 2.38-2.52 (m, 2 H), 2.58-2.72 (m, 2 H), 4.00 (dq, 2 H, J = 7.1 Hz, J = 2.4 Hz), 4.05 (s, 1 H), 7.20-7.45 (m, 5 H), 9.64 (s, 1 H) ppm. 13C NMR (50 MHz, CDCl3): δ = 14.71, 16.90, 24.55, 27.07, 54.44 (q), 57.55 (s), 60.27 (t), 72.87, 127.72, 128.56, 128.63 (d), 137.99, 169.81 (s), 202.18 (d)ppm. IR (neat): 2937, 2858, 1730, 1655, 1598, 1446, 1396, 1211, 1066, 1028, 764, 702 cm-1. MS (70 eV): m/z (%) = 303 (1) [M]+, 230 (5), 201 (10), 170 (13), 133 (28), 105 (93), 98 (100), 91 (16), 77 (38), 43 (29), 28 (11).
4-(1-Ethoxycarbonyl-2-methyl-3-oxo-2-phenyl-propyl)-morpholin-4-ium Chloride (7p): 1H NMR (200 MHz, CDCl3): δ = 1.85 (br s, 3 H), 2.29 (d, 3 H), 3.03-4.14 (m, 8 H), 4.77 (s, 1 H), 7.14-7.47 (m, 5 H), 9.41 (d, 1 H) ppm. 13C NMR (50 MHz, CDCl3): δ = 13.81, 15.06 (q), 55.84 (s), 63.22, 63.52 (q), 66.74 (t), 72.40, 128.71, 129.68 (d), 132.62, 164.50 (s), 197.96 (d) ppm. IR (KBr): 2950, 2784, 2727, 2517, 2451, 1741, 1722, 1446, 1425, 1335, 1282, 1269, 1217, 1196, 1132, 1097, 1059, 1012, 885, 842, 769, 702, 631 cm-1. MS (70 eV): m/z (%) = 306 (94) [M - HCl + 1]+, 292 (2), 232 (5), 172 (100), 130 (6), 100 (3), 88 (7), 57 (45), 43 (21).
3-Methyl-2-morpholin-4-yl-4-oxo-3-phenyl-butyric Acid Ethyl Ester (4p): 1H NMR (200 MHz, CDCl3): δ = 1.02 (dt, 3 H, J = 7.1 Hz, J = 2.5 Hz), 1.70 (d, 3 H, J = 2.5 Hz), 2.36-2.50 (m, 2 H), 2.53-2.68 (m, 2 H), 3.48-3.61 (m, 4 H), 3.82-3.96 (m, 2 H), 3.95 (d, 1 H, J = 2.5 Hz), 7.15-7.34 (m, 5 H), 9.48 (d, 1 H, J = 2.5 Hz) ppm. 13C NMR (50 MHz, CDCl3): δ = 14.64, 16.70, 53.42 (q), 57.59 (s), 60.55 (t), 67.83 (q), 72.10, 128.01, 128.63, 128.78 (d), 137.17, 169.32 (s), 201.70 (d) ppm. IR (neat): 2976, 2852, 1726, 1651, 1446, 1259, 1186, 1117, 1030, 1012, 868, 762, 700 cm-1. MS (70 eV): m/z (%) = 305 (1) [M]+, 281 (9), 232 (7), 201 (25), 172 (100), 144 (57), 105 (57), 100 (60), 91 (11), 58 (31), 28 (13).

11

Reduction with NaBH 4 to Yield α-Amino-β,β-dialkyl-γ-butyrolactones 10a-e. Method A: β-Formyl-α-aminocarboxylate (4) is synthesized by aminoalkylation of aldehyde 1 with iminium salt 3 as described above. To this reaction mixture a solution of NaBH4 (3.0 mmol, 0.11 g) in anhyd EtOH (5 mL) was added and stirring was continued. After a reaction time of 5 h at 20 °C, the mixture was quenched with HCl (6 N) and the aqueous layer was washed with Et2O several times. The aqueous layer was basified by the addition of aq sat. NaHCO3 solution and NaOH (2 N) to pH 10-12. The product was extracted with Et2O, the combined organic layers were dried (Na2SO4) and the solvent was removed in vacuo.
Reduction with NaBH 4 to Yield α-Amino-β,β-dialkyl-γ-butyrolactones 10f-i. Method B: Hydrochloride 7 (1.0 mmol) was dissolved in anhyd EtOH (10 mL), NaBH4 (2.5 mmol, 0.10 g)12 was added and the mixture was stirred for 5 h at 20 °C. Workup follows as described in method A. Analytical data of some representative synthesized compounds (* minor diastereoisomer): 3-Dimethylamino-4,4-dimethyl-dihydro-furan-2-one (10a): 1H NMR (200 MHz, CDCl3): δ = 1.09 (s, 3 H), 1.13 (s, 3 H), 2.44 (s, 6 H), 2.93 (s, 1 H), (δA = 3.80, δB = 3.88, 2 H, J = 8.9 Hz) ppm. 13C NMR (50 MHz, CDCl3): δ = 20.85, 27.09 (q), 40.96 (s), 44.51 (q), 72.72 (d), 78.36 (t), 175.43 (s) ppm. IR (neat): 2962, 2925, 2362, 2341, 1770, 1736, 1456, 1432, 1261, 1081, 1018, 798 cm-1. MS (80 eV): m/z (%) = 157 (100) [M]+, 141 (10), 128 (9), 112 (10), 102 (46), 82 (17), 58 (18), 49 (88), 42 (60).
3-Dibenzylamino-4,4-dimethyl-dihydro-furan-2-one (10c): 1H NMR (200 MHz, CDCl3): δ = 0.66 (s, 3 H), 1.07 (s, 3 H), 3.16-3.29 (m, 5 H), 4.12-4.32 (m, 2 H), 7.12-7.40 (m, 10 H) ppm. 13C NMR (50 MHz, CDCl3): δ = 20.80, 24.19 (q), 38.93 (s), 57.70 (t), 66.46 (d), 71.79 (t), 127.96, 129.01, 129.79 (d), 139.27 (s), 170.99 (s) ppm. IR (neat): 2958, 1763, 1736, 1493, 1448, 1365, 1130, 1026, 741, 696 cm-1. MS (80 eV): m/z (%) = 309 (100) [M]+, 281 (12), 253 (49), 217 (62), 195 (20), 105 (10), 91 (42), 65 (5), 53 (3), 41 (5).
4-Piperidin-1-yl-2-oxa-spiro[4.5]decan-3-one (10e): 1H NMR (200 MHz, CDCl3): δ = 0.98-1.55 (m, 16 H), 2.24-2.45 (m, 2 H), 2.45-2.60 (m, 2 H), 2.74 (s, 1 H), (δA = 3.73, δB = 3.82, 2 H, J = 9.2 Hz) ppm. 13C NMR (50 MHz, CDCl3): δ = 22.85, 23.06, 24.18, 25.63, 26.84, 29.20, 36.43 (t), 42.76 (s), 53.19 (t), 71.86, 77.28 (d), 175.42 (s) ppm. IR (KBr): 2931, 2852, 1772, 1450, 1169, 1144, 1099, 1012
cm-1. MS (80 eV): m/z (%) = 237 (100) [M]+, 192 (2), 150 (8), 141 (56), 122 (8), 110 (11), 96 (9), 84 (10), 53 (3), 41 (5).
3-Dimethylamino-4-methyl-4-phenyl-dihydro-furan-2-one (10f): 1H NMR (200 MHz, CDCl3): δ = 1.44, 1.46* (s, 3 H), 2.07, 2.44* (s, 6 H), 3.36, 3.59* (s, 1 H), (δA = 4.19, δB = 4.62, 2 H, J = 9.2 Hz), (δA = 4.12, δB = 4.24, 2 H, J = 9.0 Hz, CH2O)*, 7.12-7.43 (m, 5 H) ppm. 13C NMR (50 MHz, CDCl3): δ = 22.34*, 29.41, 43.13, 44.93* (q), 46.82, 48.26* (s), 72.14*, 72.76 (d), 76.83*, 77.43 (t), 125.74*, 127.20, 127.43*, 127.55, 128.81, 129.27* (d), 141.48*, 144.84, 174.54*, 174.92 (s) ppm. IR (film): 2974, 2943, 2904, 2877, 2841, 2789, 2254, 1770, 1498, 1446, 1163, 1024, 910, 737, 650 cm-1. MS (80 eV): m/z (%) = 219 (60) [M]+, 159 (6), 143 (4), 130 (4), 116 (11), 102 (100), 91 (4), 58 (24), 42 (31). 4-Methyl-4-phenyl-3-piperidin-1-yl-dihydro-furan-2-one; Compound with Methane (10g): 1H NMR (200 MHz, CDCl3): δ = 1.12-1.26 (m, 4 H), 1.43, 1.44* (s, 3 H), 1.47-1.60 (m, 2 H), 2.12-2.27 (m, 2 H), 2.31-2.49 (m, 2 H), 3.31, 3.53* (s, 1 H), (δA = 4.19, δB = 4.64, 2 H, J = 9.3 Hz), (δA = 4.18, δB = 4.31, 2 H, J = 9.0 Hz)*, 7.11-7.35 (m, 5 H) ppm. 13C NMR (50 MHz, CDCl3): δ = 22.77*, 29.20 (q), 24.17, 24.47*, 26.71, 27.20* (t), 46.68, 48.01* (s), 51.96, 53.69* (t), 72.87*, 73.78 (d), 76.45*, 77.56 (t), 125.47*, 127.23, 127.35, 128.42, 129.16* (d), 141.43, 145.68*, 174.73*, 175.05 (s) ppm. IR (neat): 2939, 2856, 2252, 1759, 1626, 1446, 1169, 1107, 1024, 910, 737, 650 cm-1. MS (80 eV): m/z (%) = 259 (29) [M]+, 142 (100), 117 (12), 96 (7), 68 (7), 55 (8), 41 (20).

12

The hydrochlorides may also be deprotonated with aq sat. NaHCO3 before reduction. However, the deprotonation with the reducing agent is useful for small quantity of the β-formyl-α-aminocarboxylate hydrochlorides.

13

Reduction with LiAlH 4 to Yield α,α-Dialkyl-β-dialkylamino-butane-1,4-diols 11. To hydrochlorides 7 (1.0 mmol) in anhyd THF (10 mL) was added 1 M LiAlH4 in THF (4.0 mmol, 4 mL)12 at 20 °C. After a reaction time of 10 h, the mixture was quenched very slowly with H2O and HCl (6 N). The aqueous layer was washed with Et2O several times and basified by the addition of aq sat. NaHCO3 solution and NaOH (2 N) to pH 10-12. The product was extracted with CH2Cl2, the combined organic layers were dried (Na2SO4) and the solvent was removed in vacuo. Analytical data of some representative synthesized compounds (* minor diastereoisomer): 3-Dimethylamino-2-methyl-2-phenyl-butane-1,4-diol (11a): 1H NMR (200 MHz, CDCl3): δ = 1.12*, 1.36 (s, 3 H), 2.08*, 2.50 (s, 6 H), 3.02-3.25 (m, 2 H), 3.57-4.11 (m, 3 H), 7.06-7.55 (m, 5 H) ppm. 13C NMR (50 MHz, CDCl3): δ = 16.04*, 24.58, 43.19, 44.31* (q), 44.61*, 45.00 (s), 59.96*, 60.59, 73.75*, 74.15 (t), 74.74*, 74.83, 126.11, 126.85*, 127.05, 128.49, 128.96* (d), 144.37*, 145.08 (s) ppm. IR (neat): 3350, 2947, 2881, 2843, 2252, 1498, 1466, 1444, 1385, 1026, 910, 737, 650 cm-1. MS (70 eV): m/z (%) = 223 (5) [M]+, 192 (88), 176 (11), 162 (87), 147 (39), 118 (74), 115 (76), 102 (67), 88 (94), 70 (96), 58 (95) 44 (97), 28 (100).
2-Methyl-2-phenyl-3-piperidin-1-yl-butane-1,4-diol (11b): 1H NMR (200 MHz, CDCl3): δ = 1.36 (s, 3 H), 1.41-1.64 (m, 6 H), 2.11-2.52 (m, 2 H) 2.67-2.84 (m, 2 H), 2.89-3.01 (m, 2 H), 3.08 (t, 1 H, J = 11.9 Hz), (δA = 3.66, δB = 4.04, 2 H, J = 9.9 Hz), 7.04-7.26 (m, 5 H) ppm. 13C NMR (50 MHz, CDCl3): δ = 16.27 (q), 24.64, 27.49 (t), 45.21 (s), 54.86, 60.43, 74.65 (t), 76.60, 126.07, 126.93, 128.89 (d), 144.34 (s) ppm. IR (KBr): 3361, 2937, 2854, 2252, 1468, 1454, 1442, 1039, 1026, 908, 733, 650 cm-1. MS (70 eV): m/z (%) = 263 (8) [M]+, 232 (87), 210 (33), 201 (40), 142 (92), 128 (92), 118 (87), 112 (100), 98 (91), 84 (91), 69 (71), 55 (90), 41 (98), 28 (73). 2-Benzo[1,3]dioxol-5-ylmethyl-3-dimethylamino-2-methyl-butane-1,4-diol (11c): 1H NMR (200 MHz, CDCl3): δ = 0.52, 0.88* (s, 3 H), 2.45*, 2.51 (s, 6 H), 2.59-2.73 (m, 2 H), 3.11-3.57 (m, 3 H), 3.82-4.07 (m, 2 H), 5.83, 5.84* (s, 2 H), 6.44-6.75 (m, 3 H) ppm. 13C NMR (50 MHz, CDCl3): δ = 17.93*, 21.65 (q), 36.30 (t), 41.29*, 41.49 (s), 44.39, 44.68* (q), 59.41*, 59.68, 70.27, 71.37* (t), 72.65*, 75.65 (d), 101.09, 101.23* (t), 108.04, 108.18*, 111.35*, 111.56, 123.97*, 124.08 (d), 131.15*, 131.78, 146.13, 146.39*, 147.51, 147.62* (s) ppm. IR (KBr): 3329, 2945, 2879, 2252, 1504, 1489, 1442, 1248, 1095, 1041, 906, 733, 650 cm-1. MS (80 eV): m/z (%) = 281 (70) [M]+, 249 (5), 134 (6), 113 (1), 98 (7), 88 (100), 58 (31), 44 (4).
2-Benzo[1,3]dioxol-5-ylmethyl-2-methyl-3-piperidin-1-yl-butane-1,4-diol (11d): 1H NMR (200 MHz, CDCl3): δ = 0.50, 0.87* (s, 3 H), 1.27-1.63 (m, 6 H), 2.24-2.46 (m, 2 H), 2.54-2.78 (m, 2 H), 2.84-3.05 (m, 6 H), 3.08-3.55 (m, 3 H), 3.75-4.07 (m, 2 H), 5.81, 5.82* (s, 2 H), 6.42-6.75 (m, 3 H) ppm. 13C NMR (50 MHz, CDCl3): δ = 18.25*, 21.86, 24.65*, 26.04, 27.47 (q), 36.45 (t), 41.36*, 41.55 (s), 44.57* (t), 53.32*, 54.88 (q), 59.47*, 59.68, 70.38, 71.27*(t), 74.27*, 77.56 (d), 101.06, 101.21* (t), 108.00, 108.15*, 111.35*, 111.55, 123.95* 124.05 (d), 131.27*, 131.86, 146.10, 146.36*, 147.50, 147.60* (s) ppm. IR (film): 3352, 2937, 2854, 2252, 1504, 1489, 1442, 1246, 1097, 1041, 910, 733, 650 cm-1. MS (80 eV): m/z (%) = 321 (12) [M]+, 287 (52), 257 (5), 206 (5), 175 (9), 151 (18), 134 (100), 128 (78), 98 (92), 77 (30), 41 (48).