PRACTICAL SYNTHETIC PROCEDURES
Chemoselective Deprotection of Allylic Amines
671
Amine 2h
MS (CI): m/z (%) = 176 (M+ + 1, 100), 175 (M+, 9).
Colorless oil; [a]D20 –32.5 (c = 0.6, CHCl3).
Anal. Calcd for C11H13NO: C, 75.40; H, 7.48; N, 7.99. Found: C,
75.52; H, 7.43; N, 7.94.
1H NMR: d = 0.00 (s, 6 H), 0.79 (s, 9 H), 1.27 (m, 2 H), 1.80 (m, 2
H), 2.29 (s, 3 H), 2.55 (td, 1 H, J = 12.4, 2.2 Hz), 3.16 (m, 2 H), 3.56
(m, 1 H), 3.65 (s, 3 H), 4.16 (dd, 1 H, J = 5.9, 5.4 Hz), 4.60 (d, 1 H,
J = 5.4 Hz), 6.99 (s, 1 H), 7.10 (m, 2 H), 7.31 (m, 2 H).
Tricycle 3b
Pale brown oil; [a]D20 +96.7 (c = 0.3, CHCl3).
13C NMR: d = 165.2, 134.6, 134.3, 129.4, 118.4, 82.7, 69.7, 60.5,
IR (CHCl3): 1744, 1716 cm–1.
59.3, 55.5, 44.5, 39.7, 36.1, 25.6, 20.7, 17.9.
1H NMR: d = 1.55 (dd, 1 H, J = 14.6, 10.2 Hz), 1.70 (m, 2 H), 2.10
and 2.30 (m, each 2 H), 2.71 (m, 3 H), 3.02 (s, 3 H), 3.23 (dd, 1 H,
J = 14.2, 6.8 Hz), 3.57 (d, 1 H, J = 4.4 Hz), 3.69 (dd, 1 H, J = 14.2,
6.4 Hz), 5.01 (m, 2 H).
13C NMR: d = 207.7, 166.4, 132.2, 123.8, 82.0, 61.1, 59.8, 58.9,
53.5, 51.3, 40.6, 39.7, 36.6.
MS (CI): m/z (%) = 405 (M+ + 1, 100), 404 (M+, 17).
Anal. Calcd for C22H36N2O3Si: C, 65.30; H, 8.97; N, 6.92. Found:
C, 65.42; H, 9.00; N, 6.89.
Amine 2l
Colorless oil; [a]D20 +11.3 (c = 0.8, CHCl3).
MS (CI): m/z (%) = 251 (M+ + 1, 100), 250 (M+, 9).
IR (CHCl3): 3330, 1712 cm–1.
Anal. Calcd for C13H18N2O3: C, 62.38; H, 7.25; N, 11.19. Found: C,
62.31; H, 7.24; N, 11.21.
1H NMR: d = 7.95 (d, J = 8.9 Hz, 1 H), 7.03 (d, J = 2.5 Hz, 1 H),
6.79 (dd, J = 8.9, 2.5 Hz, 1 H), 4.94 (d, J = 5.6 Hz, 1 H), 3.74 and
3.71 (s, each 3 H), 3.60 (m, 4 H), 3.21 (d, J = 10.0 Hz, 1 H), 2.36
(m, 1 H), 1.41 (m, 4 H).
Tricycle 3c
Colorless oil; [a]D20 +119.4 (c = 0.5, CHCl3).
13C NMR: d = 169.8, 157.6, 129.5, 128.3, 122.6, 114.1, 112.2, 86.2,
IR (CHCl3): 1744, 1715 cm–1.
72.6, 61.2, 59.3, 55.7, 55.6, 53.2, 32.9, 24.7, 20.6.
1H NMR: d = 2.05 (m, 1 H), 2.21 (dd, 1 H, J = 15.6, 4.8 Hz), 2.41
(m, 2 H), 2.73 (dd, 1 H, J = 15.6, 6.4 Hz), 2.99 (m, 7 H), 3.51 (dd,
1 H, J = 10.5, 4.9 Hz), 3.55 (s, 3 H), 3.79 (ddd, 1 H, J = 13.5, 11.6,
5.4 Hz), 4.27 (d, 1 H, J = 4.9 Hz), 5.56 (m, 2 H).
13C NMR: d = 210.1, 169.6, 132.3, 127.8, 82.7, 65.2, 59.2, 56.9,
53.2, 48.3, 39.2, 39.1.
MS (CI): m/z (%) = 341 (M+ + 23, 11), 319 (M+ + 1, 100), 318 (M+,
18).
Anal. Calcd for C17H22N2O4: C, 64.13; H, 6.97; N, 8.80. Found: C,
64.24; H, 7.00; N, 8.84.
Amine 2n
MS (CI): m/z (%) = 265 (M+ + 1, 100), 264 (M+, 11).
Colorless oil; [a]D20 +88.4 (c = 0.5, CHCl3).
Anal. Calcd for C14H20N2O3: C, 63.62; H, 7.63; N, 10.60. Found: C,
63.69; H, 7.62; N, 10.62.
IR (CHCl3): 3352, 1739, 1714 cm–1.
1H NMR: d = 5.67 (m, 1 H), 5.07 (m, 2 H), 4.41 (d, J = 5.2 Hz, 1 H),
3.67 (dd, J = 6.0, 5.2 Hz, 1 H), 3.51 (m, 4 H), 3.31 (m, 1 H), 3.14
(m, 2 H), 2.85 (m, 1 H), 2.32 (m, 6 H), 1.86 (br s, 1 H).
Tricycle 3d
Colorless oil; [a]D20 +191.0 (c = 0.2, CHCl3).
13C NMR: d = 207.8, 167.7, 134.6, 117.2, 83.1, 59.6, 59.2, 57.5,
IR (CHCl3): 1740, 1712 cm–1.
45.7, 45.5, 42.9, 40.6, 31.8.
1H NMR: d = 2.26 (m, 8 H), 3.05 (m, 4 H), 3.34 (m, 1 H), 3.48 (s, 3
H), 3.49 (m, 3 H), 4.35 (d, 1 H, J = 5.0 Hz), 5.61 and 5.79 (m, each
1 H).
13C NMR: d = 211.0, 170.8, 137.1, 128.8, 83.2, 77.0, 62.9, 59.6,
59.2, 47.3, 41.3, 37.9, 30.1, 28.1, 25.7.
MS (ES): m/z (%) = 253 (M+ + 1, 100), 252 (M+, 12).
Anal. Calcd for C13H20N2O3: C, 61.88; H, 7.99; N, 11.10. Found: C,
61.99; H, 8.02; N, 11.06.
Amine 2o
MS (CI): m/z (%) = 279 (M+ + 1, 100), 278 (M+, 10).
Colorless oil; [a]D20 +107.5 (c = 0.6, CHCl3).
Anal. Calcd for C15H22N2O3: C, 64.73; H, 7.97; N, 10.06. Found: C,
64.80; H, 7.98; N, 10.04.
IR (CHCl3): 3348, 1741, 1711 cm–1.
1H NMR: d = 1.64 (m, 2 H), 2.01 (m, 2 H), 2.33 (m, 4 H), 2.86 (m,
1 H), 3.03 (m, 2 H), 3.39 (m, 2 H), 3.53 (s, 3 H), 3.67 (dd, 1 H,
J = 5.2, 4.8 Hz), 4.43 (d, 1 H, J = 4.8 Hz), 4.96 (m, 2 H), 5.74 (m, 1
H).
13C NMR: d = 207.6, 167.6, 137.1, 115.6, 83.3, 59.5, 59.4, 59.3,
57.5, 45.7, 42.9, 41.1, 31.0, 26.7.
Acknowledgment
Support for this work by the DGI-MCYT (Project BQU2003-
07793-C02-01) is gratefully acknowledged. J. M. A. thanks the
UCM for a predoctoral grant.
MS (ES): m/z (%) = 267 (M+ + 1, 100), 266 (M+, 6).
Anal. Calcd for C14H22N2O3: C, 63.13; H, 8.33; N, 10.52. Found: C,
63.23; H, 8.30; N, 10.48.
References
(1) (a) Greene, T. W.; Wuts, G. M. In Protective Groups in
Organic Synthesis, 3rd. ed.; Wiley: New York, 1999.
(b) Kocienski, P. J. Protecting Groups, 3rd ed.; Thieme:
Stuttgart, 2003.
(2) For an Ir-catalyzed deprotection of allylamides, see:
Neugnot, B.; Cintrat, J.-C.; Rousseau, B. Tetrahedron 2004,
60, 3575.
Bicycle 3a
Colorless oil.
IR (CHCl3): 3352 cm–1.
1H NMR: d = 4.12 (s, 4 H), 4.72 (s, 2 H), 5.85 (s, 2 H), 6.89 (m, 2
H), 7.17 (m, 2 H).
13C NMR: d = 148.0, 130.2, 128.8, 126.4, 121.5, 118.5, 65.1, 58.5,
58.4.
(3) For a review, see: Guibé, F. Tetrahedron 1998, 54, 2967.
Synthesis 2005, No. 4, 668–672 © Thieme Stuttgart · New York