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Y. Liu et al. / Tetrahedron 67 (2011) 2206e2214
14.5. Anal. Calcd for C19H23NO5S: C, 60.46; H, 6.14; N, 3.71. Found: C,
60.68; H, 6.15; N, 3.58.
1.66e1.55 (m, 6H), 1.31 (t, J¼7.0 Hz, 3H), 1.25 (t, J¼7.1 Hz, 3H); 13C
NMR (50 MHz, CDCl3)
d 173.5, 157.5, 135.6, 129.3, 128.5, 128.4, 77.1,
62.0, 60.1, 49.6, 34.2, 26.7, 26.2, 24.6, 14.6, 14.2. Anal. Calcd for
C18H27NO5: C, 64.07; H, 8.07; N, 4.15. Found: C, 64.16; H, 7.84; N, 4.20.
4.2.2. (4-Benzenesulfonylbutyl)-N-benzyloxy-carbamic acid ethyl
ester (2b). The representative procedure was followed using 3-bro-
mobutylphenyl sulfone as the alkylating reagent to give 2b as a col-
orless oil; 94.9% yield; IR (neat) 2938,1699 cmꢁ1; 1H NMR (200 MHz,
4.2.8. N-Benzyloxy-(3-cyanopropyl)-carbamic acid ethyl ester (2g).
The representative procedure was followed using 4-bromobutyroni-
trile as the alkylating reagent to give 2g as a colorless oil; 92.7% yield;
CDCl3) d 7.98e7.81 (m, 2H), 7.74e7.47 (m, 3H), 7.47e7.30 (m, 5H), 4.81
(s, 2H), 4.19 (q, J¼7.0 Hz, 2H), 3.40 (t, J¼6.6 Hz 2H), 3.06 (t, J¼7.3 Hz,
IR (neat) 2982, 2943, 2247, 1702 cmꢁ1 1H NMR (200 MHz, CDCl3)
;
2H),1.85e1.49 (m, 4H),1.30 (t, J¼7.0Hz, 3H);13C NMR(50 MHz, CDCl3)
d
7.51e7.30(m, 5H), 4.87(s,2H), 4.24(q, J¼7.3Hz, 2H), 3.56(t, J¼6.6Hz,
2H), 2.34 (t, J¼7.0 Hz, 2H), 1.89 (quin, J¼7.0 Hz, 2H), 1.34 (t, J¼7.0 Hz,
3H); 13C NMR (50 MHz, CDCl3)
157.2, 135.2, 129.5, 128.8, 128.6, 119.1,
d
157.3, 139.2, 135.4, 133.6, 129.3, 129.2, 128.6, 128.4, 128.0, 77.1, 62.1,
55.7, 48.7, 25.7, 20.0, 14.5. Anal. Calcd for C20H25NO5S: C, 61.36; H,
6.44; N, 3.58. Found: C, 61.20; H, 6.17; N, 3.53.
d
77.2, 62.4, 48.2, 23.4,14.8,14.5. Anal. Calcd for C14H18N2O3: C, 64.10; H,
6.92; N, 10.68. Found: C, 63.88; H, 7.07; N, 10.64.
4.2.3. (5-Benzenesulfonylpentyl)-N-benzyloxy-carbamic acid ethyl
ester (2c). The representative procedure was followed using 3-
bromopentylphenyl sulfone as the alkylating reagent to give 2c as
4.2.9. N-Benzyloxy-(4-cyanobutyl)-carbamic acid ethyl ester (2h).
The representative procedure was followed using 5-chlorovaleroni-
trile as the alkylating reagent to give 2h as a colorless oil; 90.0% yield;
a colorless oil; 94.1% yield; IR (neat) 2941, 1704 cmꢁ1 1H NMR
;
(200 MHz, CDCl3)
d
8.00e7.81 (m, 2H), 7.74e7.48 (m, 3H), 7.46e7.29
IR (neat)2917, 2247,1699 cmꢁ1;1HNMR(200MHz,CDCl3)
d7.51e7.29
(m, 5H), 4.82 (s, 2H), 4.19 (q, J¼7.0 Hz, 2H), 3.38 (t, J¼6.6 Hz, 2H),
(m, 5H), 4.86 (s, 2H), 4.23 (q, J¼7.3 Hz, 2H), 3.47 (t, J¼6.2 Hz, 2H), 2.33
3.09e3.01 (m, 2H), 1.84e1.46 (m, 4H), 1.46e1.25 (m, 2H), 1.30 (t,
(t, J¼7.0 Hz, 2H), 1.72e1.64 (m, 4H), 1.33 (t, J¼7.0 Hz, 3H); 13C NMR
J¼7.0 Hz, 3H); 13C NMR (50 MHz, CDCl3)
d
157.4, 139.2, 135.5, 133.6,
(50MHz, CDCl3)d157.4,135.4,129.4,128.7,128.5,119.4,77.1, 62.2, 48.5,
26.1, 22.6, 16.7, 14.5. Anal. Calcd for C15H20N2O3: C, 65.20; H, 7.30; N,
10.14. Found: C, 65.05; H, 7.34; N, 10.08.
129.3, 129.2, 128.6, 128.4, 128.0, 77.0, 62.0, 56.1, 49.2, 26.5, 25.4,
22.4, 14.5. Anal. Calcd for C21H27NO5S: C, 62.20; H, 6.71; N, 3.45.
Found: C, 62.14; H, 6.73; N, 3.30.
4.2.10. N-Benzyloxy-(4-cyanopentyl)-carbamic acid ethyl ester
(2i). The representative procedure was followed using 6-bromo-
hexanonitrile as the alkylating reagent to give 2i as a colorless oil;
4.2.4. (5-Benzenesulfonypentyl)-N-benzyloxy-carbamic acid tert-
butyl ester (2c0). The representative procedure was followed using
tert-butyl N-benzyloxy carbamate in place of 4 and 5-bromopentyl-
phenyl sulfone as the alkylating reagent to give 2c0 as a colorless oil;
88.2% yield; IR (neat) 2940, 2245, 1704 cmꢁ1 1H NMR (200 MHz,
;
CDCl3)
d
7.51e7.29 (m, 5H), 4.85 (s, 2H), 4.22 (q, J¼7.2 Hz, 2H), 3.44
88.7% yield; IR (neat) 2976, 2938, 1699 cmꢁ1
CDCl3)
(s, 2H), 3.35 (t, J¼7.0 Hz, 2H), 3.05 (t, J¼8.1 Hz, 2H),1.82e1.60 (m, 2H),
1.49(s, 9H),1.44e1.19(m, 4H);13CNMR(50MHz,CDCl3)
156.4, 139.3,
;
1H NMR (200 MHz,
(t, J¼6.8 Hz, 2H), 2.32 (t, J¼7.0 Hz, 2H), 1.68e1.58 (m, 4H), 1.51e1.39
d
8.02e7.81 (m, 2H), 7.76e7.48(m, 3H), 7.47e7.30 (m, 5H), 4.79
(m, 2H), 1.32 (t, J¼7.1 Hz, 3H); 13C NMR (50 MHz, CDCl3)
d 157.4,
135.5, 129.3, 128.6, 128.5, 119.5, 77.1, 62.1, 48.2, 26.2, 25.7, 25.0, 17.0,
14.6. Anal. Calcd for C16H22N2O3: C, 66.18; H, 7.64; N, 9.65. Found:
66.21; H, 7.44; N, 9.71.
d
135.7,133.6,129.3,129.2,128.5,128.4,128.0, 81.2, 76.8, 56.1, 49.1, 28.3,
26.5, 25.4, 22.4. Anal. Calcd for C23H31NO5S: C, 63.72; H, 7.21; N, 3.23.
Found: C, 63.61; H, 7.22; N, 3.22.
4.2.11. [3-(N-Benzyloxy-ethoxycarbonyl-amino)-propyl]-phosphonic
acid diethyl ester (2j). The representative procedure was followed
using diethyl 3-bromopropyl phosphonate as the alkylating reagent
4.2.5. 4-(N-Benzyloxy-ethoxycarbonyl-amino)-butyric acid ethyl ester
(2d). The representative procedure was followed using ethyl 4-bro-
mobutyrate as the alkylating reagent to give 2d as a colorless oil;
93.7% yield;IR(neat)2982, 2940,1733,1703cmꢁ1;1HNMR (400MHz,
to give 2j as a colorless oil; 93.5% yield; IR (neat) 2982, 1705 cmꢁ1
;
1H NMR (200 MHz, CDCl3)
d 7.55e7.30 (m, 5H), 4.86 (s, 2H), 4.22 (q,
J¼7.0 Hz, 2H), 4.11 (quin, J¼6.8 Hz, 4H), 3.52 (t, J¼6.6 Hz, 2H),
CDCl3)
d
7.40e7.34 (m, 5H), 4.86 (s, 2H), 4.22 (q, J¼7.3 Hz, 2H), 4.12 (q,
1.94e1.68 (m, 4H), 1.35e1.27 (m, 9H); 13C NMR (50 MHz, CDCl3)
J¼7.3 Hz, 2H), 3.50 (t, J¼7.0 Hz, 2H), 2.33 (t, J¼7.3 Hz, 2H), 1.92 (quin,
d
157.4, 135.4, 129.3, 128.6, 128.4, 77.2, 62.2, 61.6 (d, J¼6.4 Hz), 50.0
J¼7.0 Hz, 2H), 1.31 (t, J¼7.3 Hz, 3H), 1.24 (t, J¼7.3 Hz, 3H); 13C NMR
(d, J¼18.7 Hz), 23.1 (d, J¼141.5 Hz), 20.4 (d, J¼4.6 Hz), 16.5 (d,
J¼5.9 Hz), 14.6. Anal. Calcd for C17H28NO6P: C, 54.68; H, 7.56; N,
3.75. Found: C, 54.60; H, 7.30; N, 3.91.
(100 MHz, CDCl3)
d 172.9, 157.4, 135.4, 129.4, 128.6, 128.5, 77.1, 62.1,
60.4, 48.9, 31.4, 22.5,14.6,14.2. Anal. Calcd for C16H23NO5: C, 62.12; H,
7.49; N, 4.53. Found: C, 62.26; H, 7.39; N, 4.43.
4.2.12. [3-(N-Benzyloxy-ethoxycarbonyl-amino)-butyl]-phosphonic
acid diethyl ester (2k). The representative procedure was followed
using diethyl 4-bromobutyl phosphonate as the alkylating reagent
4.2.6. 5-(N-Benzyloxy-ethoxycarbonyl-amino)-pentanoic acid ethyl
ester (2e). The representative procedurewas followed usingethyl5-
bromovalerate as the alkylating reagent to give 2e as a colorless oil:
to give 2k as a colorless oil; 89.4% yield; IR (neat) 2981, 1701 cmꢁ1
;
85.6% yield; IR (neat) 2981, 2939, 1732, 1702 cmꢁ1
;
1H NMR
1H NMR (200 MHz, CDCl3)
d 7.49e7.30 (m, 5H), 4.85 (s, 2H), 4.21 (q,
(200 MHz, CDCl3)
d
7.48e7.29 (m, 5H), 4.86 (s, 2H), 4.22 (q, J¼7.3 Hz,
J¼7.1 Hz, 2H), 4.07 (quin, J¼7.1 Hz, 4H), 3.44 (t, J¼6.4 Hz, 2H),
2H), 4.11 (q, J¼7.0 Hz, 2H), 3.45 (t, J¼7.0 Hz, 2H), 2.30 (t, J¼7.3 Hz, 2H),
1.73e1.60 (m, 6H), 1.35e1.25 (m, 9H); 13C NMR (50 MHz, CDCl3)
1.66e1.57 (m, 4H), 1.31 (t, J¼7.3 Hz, 3H), 1.24 (t, J¼7.3 Hz, 3H); 13C
d
157.4, 135.5, 129.3, 128.6, 128.5, 77.2, 62.1, 61.4 (d, J¼6.8 Hz), 49.1,
NMR (100 MHz, CDCl3)
d
173.2, 157.5, 135.6, 129.3, 128.5, 128.4, 77.1,
27.9 (d, J¼15.9 Hz), 25.4 (d, J¼140.1 Hz), 19.8 (d, J¼5.3 Hz), 16.5 (d,
J¼5.9 Hz), 14.6. Anal. Calcd for C18H30NO6P: C, 55.80; H, 7.81; N,
3.62. Found: C, 56.14; H, 7.66; N, 3.91.
62.0, 60.2, 48.3, 33.8, 26.5, 22.1,14.6,14.2. Anal. Calcd for C17H25NO5:
C, 63.14; H, 7.79; N, 4.33. Found: C, 63.06; H, 7.69; N, 4.37.
4.2.7. 6-(N-Benzyloxy-ethoxycarbonyl-amino)-hexanoic acid ethyl
ester (2f). The representative procedure was followed using ethyl 6-
bromohexanoate as the alkylating reagent to give 2f as a colorless
4.2.13. (3-Benzenesulfinylpropyl)-N-benzyloxy-carbamic acid ethyl
ester (2l). The representative procedure was followed using 3-bro-
mopropylphenyl sulfide as the alkylating reagent to give the corre-
sponding sulfide as a colorless oil; 57.4% yield; IR (neat) 2934,
oil; 86.1% yield; IR (neat) 2981, 2938, 1733, 1705 cmꢁ1 1H NMR
;
(200 MHz, CDCl3)
d
7.47e7.30 (m, 5H), 4.85 (s, 2H), 4.21 (q, J¼7.2 Hz,
1701 cmꢁ1; 1H NMR (200 MHz, CDCl3)
d
7.51e7.15 (m, 10H), 4.83 (s,
2H), 4.11 (q, J¼7.1 Hz, 2H), 3.43 (t, J¼7.0 Hz, 2H), 2.28 (t, J¼7.1 Hz, 2H),
2H), 4.20 (q, J¼7.3 Hz, 2H), 3.57 (t, J¼7.0 Hz, 2H), 2.90 (t, J¼7.3 Hz, 2H),