Selective Preparation of trans Disubstituted Tetrahydrofurans
45.8, 71.3, 75.7, 173.0, 187.8 ppm. IR (CHCl ):ν = 2960, 2875,
1720,1495, 1445, 1415, 1365, 1330, 1260, 1230, 1200, 1130,
˜
3
1705, 1570, 1415, 1370, 1335, 1315, 1250, 1205, 1160, 1055, 1005,
740 cm–1. MS (ESI): m/z (%) = 348 (100) [M + Na]+.
980, 910, 730 cm–1.
N-Acetylbenzoxazole-2(3H)-thione (20): 1H NMR (200 MHz,
CDCl3): δ = 3.05 (s, 3 H), 7.31 (m, 3 H), 8.10 (m, 1 H) ppm. 13C
NMR (50 MHz, CDCl3): δ = 27.6, 109.5, 116.3, 125.4, 126.0, 129.7,
1
N-Acetyl-4,4-diallyloxazolidine-2-thione (11): H NMR (200 MHz,
CDCl3): δ = 2.40 (dd, J = 14.2, 7.2 Hz, 2 H), 2.76 (s, 3 H), 2.99
(dd, J = 14.2, 7.4 Hz, 2 H), 4.31 (s, 2 H), 5.12–5.22 (m, 4 H), 5.54–
5.75 (m, 2 H) ppm. 13C NMR (50 MHz, CDCl3): δ = 27.8, 40.4,
146.3, 170.8, 179.0 ppm. IR (CHCl ): ν = 1720, 1475, 1465, 1410,
˜
3
1375, 1335, 1300, 1255, 1185, 1140, 1090, 1030, 990, 750 cm–1. MS
(ESI): m/z (%) = 152 (100) [M – Ac]+. C9H7NO2S·0.125H2O
(195.48): C 55.30, H 3.74, N 7.17; found C 55.26, H 3.51, N 7.81.
70.2, 73.7, 121.2, 130.5, 172.6, 187.4 ppm. IR (CHCl ): ν = 1705,
˜
3
1415, 1335, 1240, 1200, 1150, 1000, 980, 925 cm–1. MS (ESI): m/z
(%) = 248 (25) [M + Na]+, 206 (100) [M – Ac]+.
N-Acetylnaphtho[1,2-d]oxazole-2(1H)-thione (21): 1H NMR
(400 MHz, CDCl3): δ = 2.55 (s, 3 H), 7.58 (m, 1 H), 7.69 (t, J =
7.8 Hz, 1 H), 7.71 (d, J = 9.0 Hz, 1 H), 7.86 (d, J = 9.0 Hz, 1 H),
7.97 (d, J = 8.0 Hz, 1 H), 8.52 (d, J = 8.2 Hz, 1 H) ppm. IR (CHl3):
N-Acetyl-4,4-dibenzyloxazolidine-2-thione
(12):
1H
NMR
(200 MHz, CDCl3): δ = 2.81 (s, 3 H), 3.06 (d, J = 14.0 Hz, 2 H),
3.71 (d, J = 13.9 Hz, 2 H), 4.42 (s, 2 H), 7.12 (m, 4 H), 7.32 (m, 6
H) ppm. 13C NMR (50 MHz, CDCl3): δ = 28.5, 41.6, 71.9, 72.8,
ν = 1725, 1490, 1385, 1350, 1335, 1130, 1110, 1080, 1025, 1005,
˜
960, 810, 750 cm–1. MS (ESI): m/z (%) = 266 (100) [M + Na]+.
127.5, 128.7, 130.1, 134.5, 174.1, 186.8 ppm. IR (CHCl ): ν = 1700,
˜
3
1410, 1365, 1335, 1288, 1225, 1195, 1125, 980, 910 cm–1. MS (ESI):
Methyl (3S,6S)-3,6-Epoxy-7-(tert-butyldiphenylsilyloxy)heptanoate
(23): 1H NMR (400 MHz, CDCl3): δ = 1.07 (s, 9 H), 1.61 (m, 1
H), 1.91 (m, 1 H), 2.03 (m, 1 H), 2.15 (m, 1 H), 2.48 (dd, J = 15.0,
6.1 Hz, 1 H), 2.62 (dd, J = 15.0, 7.2 Hz, 1 H), 3.66 (m, 2 H), 3.69
(s, 3 H), 4.18 (m, 1 H), 4.40 (quint., J = 7.0 Hz, 1 H), 7.40 (m, 6
H), 7.70 (m, 4 H) ppm. 13C NMR (50 MHz, CDCl3): δ = 19.2,
26.8, 27.8, 31.7, 40.6, 51.5, 66.3, 75.6, 79.2, 127.6, 129.5, 133.6,
m/z = 348 (100) [M + Na]+, 326 (30) [M + H]+.
N-Acetyl-4,4-bis(1-methylnaphthyl)oxazolidine-2-thione (13): 1H
NMR (200 MHz, CDCl3): δ = 2.93 (s, 3 H), 3.91 (d, J = 14.7 Hz,
2 H), 4.04 (d, J = 14.6 Hz, 2 H), 4.22 (s, 2 H), 7.33–7.49 (m, 8 H),
7.76–7.89 (m, 6 H) ppm. 13C NMR (50 MHz, CDCl3): δ = 29.4,
36.2, 73.5, 74.8, 123.8, 126.0, 126.4, 127.3, 129.1, 129.2, 129.8,
135.6, 171.6 ppm. IR (CHCl ): ν = 1740, 1430, 1110, 1075, 1005,
˜
3
131.8, 133.5, 134.7, 174.3, 194.3 ppm. IR (CHCl ): ν = 1700, 1365,
˜
3
825, 740, 700 cm–1. [α]D = +7 (c = 3, CHCl3). MS (ESI): m/z (%)
1335, 1315, 1245, 1225, 1020, 980, 910, 800 cm–1. MS (ESI): m/z
= 435 (100) [M + Na]+, 615 (100).
(%) = 448 (100) [M + Na]+.
N-Acetyl-4,4-bis(2-methylnaphthyl)oxazolidine-2-thione (14): 1H
NMR (200 MHz, CDCl3): δ = 2.86 (s, 3 H), 3.31 (d, J = 14.0 Hz, Acknowledgments
2 H), 3.91 (d, J = 13.9 Hz, 2 H), 4.52 (s, 2 H), 7.26 (m, 2 H), 7.85
(m, 4 H), 7.61 (m, 2 H), 7.81 (m, 7 H) ppm. 13C NMR (50 MHz,
We thank B. Menion-Seniel for her technical help. G. J. thanks the
Conseil Général de la Guadeloupe for financial support through a
CDCl3): δ = 28.6, 41.7, 72.4, 72.8, 126.2, 126.5, 127.6, 127.7, 128.0,
fellowship.
128.6, 129.5, 132.1, 132.6, 133.4, 174.5, 194.2 ppm. IR (CHCl ): ν
˜
3
= 1700, 1510, 1415, 1365, 1335, 1235, 1195, 1125, 1025, 980,
905 cm–1. MS (ESI): m/z (%) = 448 (30) [M + Na]+, 426 (12) [M +
H]+, 342 (54), 186 (100). HRMS (ESI): calcd. for C27H23NSO2Na
[M + Na] 448.1347; found 448.1364.
[1] A. Bermejo, I. Barrachina, B. Figadère, M. C. Zafra-Polo, E.
Estornell, D. Cortes, Nat. Prod. Rep. 2005, 22, 269–303.
[2] a) J.-C. Harmange, B. Figadère, Tetrahedron: Asymmetry 1993,
4, 1711–1754; b) J. P. Wolfe, M. B. Hay, Tetrahedron 2007, 63,
261–290; c) M. C. Elliot, J. Chem. Soc. Perkin Trans. 1 2001,
2301–2323.
[3] G. Jalce, M. Seck, X. Franck, R. Hocquemiller, B. Figadère, J.
Org. Chem. 2004, 69, 3240–3241.
[4] M. T. Crimmins, B. W. King, E. A. Tabet, K. Chaudhary, J.
Org. Chem. 2001, 66, 894–902.
[5] D. Delaunay, L. Toupet, M. Le Corre, J. Org. Chem. 1995, 60,
6604–6607; A. Hisham, U. Sreekala, L. Pieters, T. De Bruyne,
H. Van den Heuvel, M. Claeys, Tetrahedron 1993, 49, 6913.
[6] Y. Wu, Y.-Q. Yang, Q. Hu, J. Org. Chem. 2004, 69, 3990–3992.
[7] F. Fülöp, G. Csirinyi, G. Bernáth, Synthesis 1985, 1149–1151.
[8] T. Hirao, A. Yamada, K. Hayashi, Y. Oshiro, T. Agawa, Bull.
Chem. Soc. Jpn. 1982, 55, 1163–1167.
N-Acetyl-4,4-spirocyclohexyloxazolidine-2-thione (15): 13C NMR
(50 MHz, CDCl3): δ = 23.4, 24.1, 28.3, 31.7, 69.9, 76.2, 172.9,
187.5 ppm. IR (CHCl ): ν = 2935, 2860, 1710, 1455, 1420, 1365,
˜
3
1335, 1320, 1255, 1240, 1190, 1555, 1035, 1005, 990, 960 cm–1. MS
(ESI): m/z (%) = 236 (100) [M + Na]+.
N-Acetyl-4,4-diphenyloxazolidine-2-thione
(16):
1H
NMR
(200 MHz, CDCl3): δ = 2.78 (s, 3 H), 4.90 (s, 2 H), 7.36 (m, 10
H) ppm. 13C NMR (50 MHz, CDCl3): δ = 27.6, 76.2, 82.6, 127.7,
128.3, 128.4, 138.1, 171.0, 186.5 ppm. IR (CHCl ): ν = 1715, 1365,
˜
3
1330, 1260, 1190, 1170, 1050, 1000, 960, 805 cm–1. MS (ESI): m/z
(%) = 320 (100) [M + Na]+.
N-Acetyl-4,4-diisopropyloxazolidine-2-thione (17): 13C NMR
(50 MHz, CDCl3): δ = 17.4, 18.2, 28.1, 32.9, 73.0, 77.9, 173.2,
[9] M. Ballabeni, R. Ballini, F. Bigi, R. Maggi, M. Parrini, G. Pre-
dieri, G. Sartori, J. Org. Chem. 1999, 64, 1029–1032.
188.6 ppm. IR (CHCl ): ν = 2970, 2930, 1710, 1415, 1365, 1325,
˜
3
[10] S. Kotha, A. Kuki, Tetrahedron Lett. 1992, 33, 1565–1568.
[11] D. Hoope, R. Follman, Chem. Ber. 1976, 109, 3047–3061.
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Higley, H. S. Kezar III, T. P. Maduskuie, E. S. Shimshick,
R. R. Wexler, Bioorg. Med. Chem. Lett. 1995, 5, 16–172.
[13] Conversion to the methyl esters during methanolysis did not
erode the dr by retro-Michael–Michael equilibration because
the observed ratios were in the range of 1:1 to 100:0 (if equili-
bration occurred dr would be expected to be quite similar).
Nevertheless, partial retro-Michael–Michael equilibration can-
not definitely be ruled out as the relative rate of the meth-
anolysis/retro-Michael reactions could also be dependent on
the oxazolidine-2-thione. We thank one of the referees for
pointing out this mechanistic issue.
1265, 1235, 1210, 1180, 1165, 1150, 1025, 1005, 985, 965 cm–1.
N-Acetyl-4,4-dimethyl-5,5-diphenyloxazolidine-2-thione (18): 1H
NMR (200 MHz, CDCl3): δ = 1.50 (s, 6 H), 2.80 (s, 3 H), 7.36 (m,
6 H), 7.48 (m, 4 H) ppm. 13C NMR (50 MHz, CDCl3): δ = 23.8,
27.9, 72.7, 95.3, 126.7, 128.3, 137.7, 172.7, 185.7 ppm. IR (CHCl3):
ν = 1710, 1495, 1450, 1345, 1290, 1245, 1200, 1170,1150, 1020,
˜
975 cm–1. MS (ESI): m/z (%) = 348 (67) [M + Na]+, 250 (100).
N-Acetyl-5,5-dimethyl-4,4-diphenyloxazolidine-2-thione (19): 1H
NMR (200 MHz, CDCl3): δ = 1.23 (s, 6 H), 2.85 (s, 3 H), 7.35 (br.
s, 10 H) ppm. 13C NMR (50 MHz, CDCl3): δ = 25.0, 28.5, 80.9,
90.9, 127.8, 128.0, 128.7, 136.3, 171.8, 186.8 ppm. IR (CHCl ): ν =
˜
3
Eur. J. Org. Chem. 2009, 378–386
© 2009 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
www.eurjoc.org
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