PAPER
Efficient Synthesis of N-Protected Trisubstituted Oxazolidines
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2-Ethoxy-4-[2-(2-chloro-1,1,2,2-tetrafluoroethoxy)-1,1,2,2-tet-
rafluoroethanesulfonyl]-1-oxa-4-azaspiro[4.4]nonane (6bab)
Colorless oil.
19F NMR (282 MHz, CDCl3): d = –81.8 (s, 2 F, CF2O), –88.9 (s, 2
F, OCF2), –114.8 (br, 2 F, CF2S), –137.8 (dt, J = 53.6 Hz, 5.0 Hz,
HCF2).
IR (KBr): 2979, 1396, 1305, 1204, 1174, 1047, 970 cm–1.
MS (EI, 70 eV): m/z (%) = 438 (M+ – Me, 29), 380 (M+ – i-BuO,
+
81), 70 (M+ – RfSO2NHC3H6O, 88), 57 (i-Bu+, 100), 43 (C3H7 , 61).
1H NMR (300 MHz, CDCl3): d = 5.25 (dd, J = 5.1 Hz, 1.8 Hz, 1 H),
3.90–3.73 (m, 3 H), 3.52 (dq, J = 7.2 Hz, 9.6 Hz, 1 H), 2.39–2.32
(m, 1 H), 2.16 (br, 2 H), 1.86–1.67 (m, 5 H), 1.23 (t, J = 7.2 Hz, 3
H, CH3).
Anal. Calcd for C13H19F8NO5S: C, 34.44; H, 4.19; N, 3.09. Found:
C, 34.77; H, 4.30; N, 3.38.
2-Ethoxy-4-[1,1,2,2-tetrafluoro-2-(1,1,2,2-tetrafluoroeth-
oxy)ethanesulfonyl]-1-oxa-4-azaspiro[4.4]nonane (6cab)
Colorless oil.
IR (KBr): 2979, 1394, 1284, 1142, 1046 cm–1.
1H NMR (300 MHz, CDCl3): d = 5.87 (tt, J = 52.8 Hz, 3.0 Hz, 1 H,
HCF2), 5.25 (dd, J = 4.8 Hz, 1.8 Hz, 1 H), 3.90–3.73 (m, 3 H), 3.52
(dq, J = 6.6 Hz, 9.6 Hz, 1 H), 2.39–2.32 (m, 1 H), 2.16 (br, 2 H),
1.86–1.64 (m, 5 H), 1.23 (t, J = 7.1 Hz, 3 H, CH3). 19F NMR (282
MHz, CDCl3): d = –81.8 (t, J = 12.1 Hz, 2 F, CF2O), –88.8 (d, J =
8.2 Hz, 2 F, OCF2), –114.2 (br, 2 F, CF2S), –137.7 (dt, J = 56 Hz,
5.1 Hz, 2 F, HCF2).
19F NMR (282 MHz, CDCl3): d = –74.1 (s, 2 F, ClCF2), –82.2 (t,
J = 13 Hz, 2 F, CF2O), –87.2 (t, J = 12.3 Hz, 2 F, OCF2), –114.1 (s,
2 F, CF2S).
MS (EI, 70 eV): m/z (%) = 487/485 (M+, 11/27), 458/456 (M+ – Et,
37/96), 442/440 (M+ – EtO, 13/35), 170 (M+ – RfSO2, 63), 141
+
+
(M+ – RfSO2Et, 99), 96 (C6H8O+, 80), 67 (C5H7 , 54), 55 (C4H7 ,
100), 41(C3H5 , 58).
+
Anal. Calcd for C13H16ClF8NO5S: C, 32.13; H, 3.30; N, 2.88.
Found: C, 32.45; H, 3.13; N, 3.23.
2-Isobutoxy-4-[2-(2-chloro-1,1,2,2-tetrafluoroethoxy)-1,1,2,2-
tetrafluoroethanesulfonyl]-1-oxa-4-azaspiro[4.4]nonane (6bbb)
Colorless oil.
IR (KBr): 2963, 1397, 1205, 1174, 1041, 970 cm–1.
MS (EI, 70 eV): m/z (%) = 451 (M+, 32), 422 (M+ – Et, 100), 406
(M+ – EtO, 43), 170 (M+ – RfSO2, 53), 141 (M+ – RfSO2Et, 81), 96
+
+
+
(C6H8O+, 70), 67 (C5H7 , 46), 55 (C4H7 , 85), 41 (C3H5 , 50).
Anal. Calcd for C13H17F8NO5S: C, 34.59; H, 3.77; N, 3.10. Found:
C, 34.99; H, 3.80; N, 3.50.
1H NMR (300 MHz, CDCl3): d = 5.22 (dd, J = 5.1 Hz, 1.5 Hz, 1 H,),
3.88 (dd, J = 10.2 Hz, 5.1 Hz, 1 H), 3.78 (dd, J = 10.2 Hz, 6.0 Hz,
1 H), 3.51 (dd, J = 9.0 Hz, 6.6 Hz, 1 H), 3.20 (dd, J = 9.0 Hz, 6.0
Hz, 1 H), 2.39–2.34 (m, 1 H), 2.16 (br, 2 H), 1.92–1.67 (m, 6 H),
0.93 (d, J = 6.9 Hz, 3 H, CH3), 0.92 (d, J = 6.6 Hz, 3 H, CH3).
19F NMR (282 MHz, CDCl3): d = –74.1 (s, 2 F, ClCF2), –82.2 (t,
J = 12.8 Hz, 2 F, CF2O), –87.1 (t, J = 12.7 Hz, 2 F, OCF2), –114.2
(s, 2 F, CF2S).
2-Isobutoxy-4-[1,1,2,2-tetrafluoro-2-(1,1,2,2-tetrafluoroeth-
oxy)ethanesulfonyl]-1-oxa-4-azaspiro[4.4]nonane (6cbb)
Colorless oil.
IR (KBr): 2963, 1395, 1284, 1143, 1034 cm–1.
1H NMR (300 MHz, CDCl3): d = 5.86 (tt, J = 52.5 Hz, 3.0 Hz, 1 H,
HCF2), 5.22 (dd, J = 4.8 Hz, 1.5 Hz, 1 H), 3.87 (dd, J = 10.2 Hz, 5.1
Hz, 1 H), 3.77 (dd, J = 10.5 Hz, 1.8 Hz, 1 H), 3.51 (dd, J = 9.3 Hz,
6.9 Hz, 1 H), 3.20 (dd, J = 9.3 Hz, 6.3 Hz, 1 H), 2.38–2.32 (m, 1 H),
2.15 (br, 2 H), 1.92–1.69 (m, 6 H), 0.926 (d, J = 6.6 Hz, 3 H, CH3),
0.919 (d, J = 6.9Hz, 3 H, CH3).
MS (EI, 70 eV): m/z (%) = 515/513 (M+, 3/8), 486/484 (M+ – Et, 5/
13), 442/440 (M+ – i-BuO, 5/14), 198 (M+ –RfSO2, 11), 142 (M+ –
+
RfSO2-i-Bu, 29), 96 (C6H8O+, 30), 57 (i-Bu+, 100), 41 (C3H5 , 40).
Anal. Calcd for C15H20ClF8NO5S: C, 35.05; H, 3.89; N, 2.73.
Found: C, 35.27; H, 4.07; N, 2.80.
13C NMR (75 MHz, CDCl3): d = 99.7, 74.6, 54.3, 28.3, 22.6, 22.1,
27.9, 19.1, 18.8.
5-Ethoxy-3-[1,1,2,2-tetrafluoro-2-(1,1,2,2-tetrafluoroeth-
oxy)ethanesulfonyl]-2,2-dimethyloxazolidine (6caa)
Colorless oil.
IR (KBr): 2985, 1384, 1284, 1163, 1046, 1000 cm–1.
1H NMR (300 MHz, CDCl3): d = 5.86 (tt, J = 52.5 Hz, 3.0 Hz, 1 H,
HCF2), 5.24 (dd, J = 4.5 Hz, 1.8 Hz, 1 H), 3.86–3.75 (m, 3 H), 3.52
(dq, J = 7.2 Hz, 9.3 Hz, 1 H), 1.75 (s, 3 H, CH3), 1.64 (s, 3 H, CH3),
1.23 (t, J = 7.0 Hz, 3 H, CH3).
19F NMR (282 MHz, CDCl3): d = –81.8 (t, J = 11.0 Hz, 2 F, CF2O),
–88.9 (m, 2 F, OCF2), –114.6 (br, 2 F, CF2S), –137.8 (dt, J = 54 Hz,
5.5 Hz, 2 F, HCF2).
19F NMR (282 MHz, CDCl3): d = –81.8 (t, J = 13.1 Hz, 2 F, CF2O),
–88.8 (d, J = 9.0 Hz, 2 F, OCF2), –114.3 (br, 2 F, CF2S), –137.8 (dt,
J = 53.9 Hz, 5.1 Hz, HCF2).
MS (EI, 70 eV): m/z (%) = 479 (M+, 11), 450 (M+ – Et, 20), 406 (M+
– i-BuO, 18), 198 (M+ – RfSO2, 12), 142 (M+ –RfSO2-i-Bu, 31), 96
(C6H8O+, 31), 57 (i-Bu+, 100), 41 (C3H5 , 43).
+
Anal. Calcd for C15H21F8NO5S: C, 37.58; H, 4.38; N, 2.92. Found:
C, 37.74; H, 4.64; N, 2.96.
5-Ethoxy-3-(nonafluorobutane-1-sulfonyl)-2,2-dimethyloxazo-
lidine (6daa)
Colorless oil.
IR (KBr): 2985, 1385, 1238, 1140, 1046, 1005 cm–1.
1H NMR (300 MHz, CDCl3): d = 5.25 (dd, J = 4.2 Hz, 1.8 Hz, 1 H),
3.87–3.75 (m, 3 H), 3.51 (dq, J = 7.2 Hz, 9.6 Hz, 1 H), 1.76 (s, 3 H,
CH3), 1.65 (s, 3 H, CH3), 1.24 (t, J = 6.3 Hz, 3 H, CH3).
19F NMR (282 MHz, CDCl3): d = –81.3 (m, 3 F, CF3), –111.3 (br, 2
F, CF2S), –121.5 (s, 2 F, CF2), –126.4 (m, 2 F, CF2).
MS (EI, 70 eV): m/z (%) = 410 (M+ – Me, 100), 380 (M+ – EtO, 30),
129 (M+ – RfSO2NH, 62), 70 (M+ – RfSO2NH-C3H6O, 39).
Anal. Calcd for C11H15F8NO5S: C, 31.06; H, 3.53; N, 3.29. Found:
C, 31.01; H, 3.82; N, 3.35.
5-Isobutoxy-3-[1,1,2,2-tetrafluoro-2-(1,1,2,2-tetrafluoroeth-
oxy)ethanesulfony]-2,2-dimethyloxazolidine (6cba)
Colorless oil.
IR (KBr): 2963, 1384, 1196, 1162, 1032 cm–1.
MS (EI, 70 eV): m/z (%) = 412 (M+ – Me, 91), 382 (M+ – EtO, 31),
129 (M+ – RfSO2NH, 84), 70 (M+ – RfSO2NHC3H6O, 100), 43
1H NMR (300 MHz, CDCl3): d = 5.87 (tt, J = 52.2 Hz, 3.0 Hz, 1 H,
HCF2), 5.22 (dd, J = 4.5 Hz, 1.8 Hz, 1 H), 3.87–3.78 (m, 2 H), 3.53
(dd, J = 9.0 Hz, 6.3 Hz, 1 H), 3.19 (dd, J = 9.0 Hz, 6.3 Hz, 1 H),
1.92–1.81 (m, 1 H), 1.75 (s, 3 H, CH3), 1.65 (s, 3 H, CH3), 0.923 (d,
J = 6.6 Hz, 3 H, CH3), 0.916 (d, J = 6.6 Hz, 3 H, CH3).
+
(C3H7 , 60).
Anal. Calcd for C11H14F9NO4S: C, 30.91; H, 3.28; N, 3.28. Found:
C, 30.75; H, 3.59; N, 3.35.
Synthesis 2005, No. 13, 2137–2142 © Thieme Stuttgart · New York