5784
B.V.S. Reddy et al. / Tetrahedron Letters 54 (2013) 5781–5784
MOMO
OMOM
a
Ts
NC
Ts
NC
29
30
MOMO
OMOM
OTBS
Ts
b
OTBS
NC
OMOM
31
c
OH
O
OH
OH OH
O
+
O
O
OH
OH
Attenol A
Attenol B
Scheme 4. Reagents and conditions: (a) 15, n-BuLi, THF:HMPA (4:1), ꢁ78 °C to rt, 3 h, 85%; (b) 28, n-BuLi, THF:HMPA (4:1), ꢁ78 °C to rt, 3 h, 87%; (c) p-TSA, MeOH, 9 h, 75%.
128.3, 127.9, 127.8, 119.8, 73.4, 70.4, 68.3, 51.5, 35.3; IR (neat): mmax 3450, 3031,
Acknowledgements
2949, 1722, 1436, 1273, 1219, 1097, 772 cmꢁ1; MS (ESI): m/z 273 (M+Na)+.
(2R,4S)-6-(Benzyloxy)-4-(methoxymethoxy)hexane-1,2-diol (10): ½a D20
ꢁ57.5 (c 1.0,
ꢂ
CHCl3); 1HNMR(500 MHz, CDCl3): d7.38–7.26(m,5H),4.67(d,J = 6.6 Hz, 1H), 4.63
(d, J = 6.6 Hz, 1H), 4.50 (s, 2H), 4.00–3.92 (m, 2H), 3.64–3.51 (m, 1H), 3.48–3.42 (m,
1H), 3.39 (s, 3H), 2.47 (br s, 2H), 1.95–1.79 (m, 2H), 1.77–1.59 (m, 1H), 1.57–1.50
(m, 1H); 13C NMR (75 MHz, CDCl3): d 137.6, 132.9, 129.4, 128.2, 127.5, 127.4, 96.7,
B.P.R. and N.S thank CSIR, New Delhi, for the award of fellow-
ships. B.V.S. thanks CSIR, New Delhi for financial support as part
of XII five year plan program under title ORIGIN (CSC-0108).
74.7, 74.1, 72.2, 69.4, 68.4, 55.5, 35.2, 34.8; IR (neat):
mmax 3411, 2926, 1452, 1366,
1275, 1101, 1032, 916, 772 cmꢁ1; MS (ESI): m/z 307 (M+Na)+.
Supplementary data
(R)-4-Benzyl-3-((R)-4-(benzyloxy)-2-methylbutanoyl) oxazolidin-2-one (17): ½a D20
ꢁ81.3 (c 1.0, CHCl3); 1H NMR (300 MHz, CDCl3): d 7.39–7.10 (m, 10H), 4.43 (s, 2H),
4.18–4.04 (m, 1H), 4.01–3.85 (m, 1H), 3.72 (t, J = 8.4 Hz, 1H), 3.26 (dd, J = 3.2,
13.4 Hz, 1H), 3.19 (dd, J = 3.2, 13.4 Hz, 1H), 3.07 (t, J = 7.1 Hz, 2H), 2.76–2.62 (m,
1H), 2.10–1.96 (m, 2H), 1.24 (d, J = 6.7 Hz, 3H); 13C NMR (75 MHz, CDCl3): d 176.9,
153.1, 138.3, 135.3, 129.3, 128.7, 128.2, 127.4, 127.1, 72.7, 68.3, 65.7, 55.1, 35.8,
ꢂ
Supplementary data associated with this article can be found,
References and notes
35.0, 33.5, 17.8; IR (neat): mmax 3029, 2924, 2855, 1778, 1698, 1479, 1353, 1209,
1096, 765, 699 cmꢁ1; HRMS (ESI) m/z calcd for C22H25O4NNa [M+Na]+ 390.1674,
found: 390.1674.
(4S,5R)-7-(Benzyloxy)-5-methylhept-1-en-4-ol (19): ½a D20
ꢂ
ꢁ10.7 (c 1.0, CHCl3); 1H
NMR (300 MHz, CDCl3):d 7.38–7.27 (m, 5H), 5.91–5.78 (m, 1H), 5.15–5.07 (m, 2H),
4.52(s, 2H), 3.62–3.55(m, 1H), 3.54–3.43(m, 2H),2.54–2.45(m, 1H), 2.25–2.09(m,
1H), 1.97–1.88 (m, 1H), 1.84–1.66 (m, 1H), 1.64–1.53 (m, 1H), 1.13 (d, J = 6.7 Hz,
3H); 13CNMR(75 MHz,CDCl3):d135.8, 135.5, 128.4, 127.7, 117.2, 117.3, 74.3,73.0,
68.1, 38.8, 35.9, 32.3, 16.1; IR (neat): mmax 3439, 3031, 2931, 2867, 1640, 1454,
1364, 1097, 995, 737 cmꢁ1; HRMS (ESI) m/z calcd for C15H22O2Na [M+Na]+
257.1512, found: 257.1510.
(2R,3R,4R)-6-(Benzyloxy)-3-(methoxymethoxy)-4-methylhexane-1,2-diol (22): ½a D20
ꢂ
ꢁ80.5 (c 1.0, CHCl3); 1H NMR (300 MHz, CDCl3): d 7.40–7.24 (m, 5H), 4.70 (d,
J = 6.5 Hz, 1H), 4.61 (d, J = 6.7 Hz, 1H), 4.56–4.46 (m, 2H), 3.79–3.64 (m, 4H), 3.60–
3.53 (m, 1H), 3.54–3.46 (m, 1H), 3.42 (s, 3H), 2.02–1.85 (m, 2H), 1.80–1.63 (br s,
2H), 1.46–1.38 (m, 1H), 0.97 (d, J = 6.8 Hz, 3H); 13C NMR (75 MHz, CDCl3): d 138.1,
128.3, 127.7, 98.8, 87.2, 73.0, 71.1, 68.4, 63.2, 56.0, 32.0, 29.6, 16.4; IR (neat): mmax
3402, 3051, 2941, 2877, 1645, 1444, 1364, 1097 cmꢁ1; HRMS (ESI) m/z calcd for
C
16H26O5Na [M+Na]+ 321.1655, found: 321.1672.
Attenol A (1): ½a D20
ꢂ
ꢁ8.6 (c 1.0, CHCl3); 1H NMR (500 MHz, CDCl3), 5.81 (ddt, J = 6.7,
10.2, 16.9 Hz, 1H), 5.72–5.64 (m, 1H), 5.62–5.50 (m, 1H), 5.01 (dd, J = 1.8, 17.2 Hz,
1H), 4.95 (d, J = 10.1 Hz, 1H), 4.35–4.28 (m, 1H), 3.87–3.79 (m, 1H), 3.74–3.58 (m,
3H), 3.32 (dd, J = 1.4, 10.1 Hz, 1H), 2.56–2.48 (m, 1H), 2.47–2.37 (m, 1H), 2.34–2.23
(m, 1H), 2.16–2.06 (m, 3H), 2.05–1.97 (m, 2H), 1.89–1.79 (m, 1H), 1.79–1.61 (m,
7H), 1.58–1.40 (m, 5H), 0.88 (d, J = 6.6 Hz, 3H); 13C NMR (75 MHz, CDCl3): d 138.6,
129.4, 128.0, 114.5, 106.3, 77.9, 70.0, 69.5, 61.8, 43.7, 38.5, 36.6, 33.8, 33.6, 32.8,
30.8, 30.3, 29.0, 25.0, 17.2; IR (neat): mmax 3331, 2938, 1447, 1196, 1049 cmꢁ1
HRMS (ESI) m/z calcd for C22H38O5Na [M+Na]+ 405.2611, found: 405.2600.
;
Attenol B (2): ½a D20
ꢂ
+24 (c 0.5, CHCl3); 1H NMR (500 MHz, CDCl3): d 5.81 (ddt, J = 7.0,
10.1, 17.1 Hz, 1H), 5.57–5.49 (m, 2H), 5.01 (dd, J = 1.6, 17.1 Hz, 1H), 4.95 (br d,
J = 10.1 Hz, 1H), 4.08 (t, J = 7.0 Hz, 1H), 4.00–3.89 (m, 2H), 3.93 (br s, 1H), 3.73 (br s,
1H), 3.67–3.58 (m, 2H), 2.43–2.35 (m, 2H), 2.34–2.25 (m, 2H), 2.12–2.04 (m, 2H),
2.04–1.98 (m, 1H), 1.92–1.83 (m, 2H) 1.82–1.74 (m, 1H), 1.73–1.49 (m, 8H), 1.48–
1.38 (m, 2H), 1.34 (dd, J = 5.4, 14.0 Hz, 1H), 1.12 (d, J = 7.0 Hz, 3H); 13C NMR
(75 MHz, CDCl3): d 138.8, 128.4, 127.7, 114.5, 109.6, 83.0, 80.0, 69.8, 68.9, 61.8,
42.5, 36.8, 34.2, 33.7, 33.6, 31.2, 31.1, 30.3, 30.2, 25.0, 23.0, 16.9; IR (neat): mmax
3322, 2931, 1437, 1044 cmꢁ1; HRMS (ESI) m/z calcd for C22H38O5Na [M+Na]+
405.2611, found: 405.2610.
16. (S,E)-Methyl 6-(benzyloxy)-4-hydroxyhex-2-enoate (6): ½a D20
ꢁ11.8 (c 1.0, CHCl3);
ꢂ
1H NMR (300 MHz, CDCl3): d 7.39–7.27 (m, 5H), 6.94 (dd, J = 3.7, 15.1 Hz, 1H),
6.11 (dd, J = 1.5, 15.1 Hz, 1H), 4.57–4.50 (m, 3H), 3.74 (s, 3H), 3.73–3.62 (m, 2H),
2.05–1.92 (m, 1H), 1.88–1.76 (m, 1H); 13C NMR (75 MHz, CDCl3): d 166.9, 149.8,