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T. Muller et al. / Tetrahedron 62 (2006) 12025–12040
7.30 (m, 5H, Ar-H). 13C NMR (75 MHz, CDCl3) d: 11.3–
12.3 (C-5a, C-7a, C-8a, CH3CO2), 20.5 (C-4), 20.6 (C-20),
23.7 (C-2a), 26.2 (C-30), 29.4–30.0 (C-40 to C-110), 31.5
(C-3), 39.6 (C-10), 70.5 (C-120), 72.9 (CH2Ph), 76.5 (C-2),
117.3 (C-5), 123.1 (C-6), 124.9 (C-7), 126.7 (C-8), 127.7–
128.4 (Ar-CH), 138.7 (Ar-C), 140.5 (C-4a), 149.8 (C-8b),
169.6 (C]O).
purified by flash column chromatography on silica gel
(hexane–EtOAc: 9:1) to give 0.50 g of a white solid (93%).
1H NMR (300 MHz, CDCl3) d: 1.24 (s, 3H, H-2a), 1.26 (br
s, 16H, H-20 to H-90), 1.60 (m, 4H, H-10, H-100), 1.77 (m,
2H, H-3), 2.12 (s, 3H, H-7a), 2.16 (s, 3H, H-5a), 2.21 (s,
3H, H-8a), 2.59 (t, 2H, J 6.8 Hz, H-4), 3.47 (t, 2H,
J 6.6 Hz, H-110), 3.64 (s, 3H, OCH3), 4.52 (s, 2H, CH2Ph),
7.30 (m, 5H, Ar-H). 13C NMR (75 MHz, CDCl3) d: 11.7
(C-5a), 11.8 (C-7a), 12.6 (C-8a), 20.7 (C-4), 23.7 (C-20),
23.9 (C-2a), 26.2 (C-30), 29.4–31.4 (C-40 to C-100), 31.7
(C-3), 39.8 (C-10), 60.4 (OCH3), 70.6 (C-110), 72.9
(CH2Ph), 74.8 (C-2), 117.5 (C-5), 122.9 (C-6), 125.7 (C-7),
127.6 (C-8), 138.8 (Ar-C), 147.8 (C-4a), 149.4 (C-8b).
4.1.30. 2-(13-(Benzyloxy)tridecyl)-2,5,7,8-tetramethyl-
3,4-dihydro-2H-chromen-6-yl acetate (11c). Yield 89%
(0.25 g). 1H NMR (300 MHz, CDCl3) d: 1.24 (s, 3H,
H-2a), 1.28 (br s, 20H, H-20 to H-110), 1.59 (m, 4H, H-10,
H-120), 1.77 (m, 2H, H-3), 2.13 (s, 6H, H-5a, H-7a), 2.17
(s, 3H, H-8a), 2.36 (s, 3H, CH3C]O), 2.61 (t, 2H,
J 6.8 Hz, H-4), 3.47 (t, 2H, J 6.6 Hz, H-130), 4.52 (s, 2H,
CH2Ph), 7.30 (m, 5H, Ar-H). 13C NMR (75 MHz, CDCl3)
d: 11.3–12.3 (C-5a, C-7a, C-8a, CH3C]O), 20.5 (C-4),
20.6 (C-20), 23.7 (C-2a), 26.2 (C-30), 29.3–30.0 (C-40 to
C-120), 31.5 (C-3), 39.6 (C-10), 70.5 (C-130), 72.9
(CH2Ph), 76.5 (C-2), 117.3 (C-5), 123.1 (C-6), 124.9
(C-7), 126.7 (C-8), 127.7–128.5 (Ar-CH), 138.7 (Ar-C),
140.5 (C-4a), 149.8 (C-8b), 169.4 (C]O).
4.1.34. 2-(12-(Benzyloxy)dodecyl)-6-methoxy-2,5,7,8-
tetramethyl-3,4-dihydro-2H-chromene (12b). Yield 87%
(0.41 g). 1H NMR (300 MHz, CDCl3) d: 1.25 (s, 3H,
H-2a), 1.27 (br s, 18H, H-20 to H-100), 1.61 (m, 4H, H-10,
H-110), 1.77 (m, 2H, H-3), 2.12 (s, 3H, H-7a), 2.16 (s,
3H, H-5a), 2.20 (s, 3H, H-8a), 2.58 (t, 2H, J 6.8 Hz, H-4),
3.47 (t, 2H, J 6.6 Hz, H-120), 3.64 (s, 3H, OCH3), 4.52 (s,
2H, CH2Ph), 7.30 (m, 5H, Ar-H). 13C NMR (75 MHz,
CDCl3) d: 11.7 (C-5a), 11.8 (C-7a), 12.5 (C-8a), 20.7
(C-4), 23.7 (C-20), 23.8 (C-2a), 26.2 (C-30), 29.5–31.2
(C-40 to C-110), 31.7 (C-3), 39.8 (C-10), 60.3 (OCH3),
70.6 (C-120), 72.9 (CH2Ph), 74.8 (C-2), 117.5 (C-5), 122.9
(C-6), 125.7 (C-7), 127.6 (C-8), 138.8 (Ar-C), 147.8
(C-4a), 149.4 (C-8b).
4.1.31. 2-(14-(Benzyloxy)tetradecyl)-2,5,7,8-tetramethyl-
3,4-dihydro-2H-chromen-6-yl acetate (11d). Yield 97%
(0.71 g). 1H NMR (300 MHz, CDCl3) d: 1.26 (s, 3H,
H-2a), 1.30 (br s, 22H, H-20 to H-120), 1.60 (m, 4H, H-10,
H-130), 1.78 (m, 2H, H-3), 2.13 (s, 6H, H-5a, H-7a), 2.17
(s, 3H, H-8a), 2.36 (s, 3H, CH3C]O), 2.61 (t, 2H,
J 6.8 Hz, H-4), 3.47 (t, 2H, J 6.6 Hz, H-140), 4.53 (s, 2H,
CH2Ph), 7.31 (m, 5H, Ar-H). 13C NMR (75 MHz, CDCl3)
d: 11.3–12.4 (C-5a, C-7a, C-8a, CH3CO2), 20.5 (C-4), 20.6
(C-20), 23.7 (C-2a), 26.2 (C-30), 29.2–30.0 (C-40 to C-130),
31.5 (C-3), 39.6 (C-10), 70.5 (C-140), 72.9 (CH2Ph), 76.5
(C-2), 117.3 (C-5), 123.1 (C-6), 124.9 (C-7), 126.7 (C-8),
127.7–128.5 (Ar-CH), 138.7 (Ar-C), 140.5 (C-4a), 149.8
(C-8b), 169.4 (C]O).
4.1.35. 2-(13-(Benzyloxy)tridecyl)-6-methoxy-2,5,7,8-
tetramethyl-3,4-dihydro-2H-chromene (12c). Yield 81%
(0.47 g). 1H NMR (300 MHz, CDCl3) d: 1.24 (s, 3H,
H-2a), 1.27 (br s, 20H, H-20 to H-110), 1.61 (m, 4H, H-10,
H-120), 1.78 (m, 2H, H-3), 2.12 (s, 3H, H-7a), 2.17 (s,
3H, H-5a), 2.19 (s, 3H, H-8a), 2.58 (t, 2H, J 6.8 Hz, H-4),
3.47 (t, 2H, J 6.6 Hz, H-130), 3.64 (s, 3H, OCH3), 4.52 (s,
2H, CH2Ph), 7.30 (m, 5H, Ar-H). 13C NMR (75 MHz,
CDCl3) d: 11.7 (C-5a), 11.8 (C-7a), 12.5 (C-8a), 20.7 (C-4),
23.7 (C-20), 23.8 (C-2a), 26.2 (C-30), 29.5–31.3 (C-40 to
C-120), 31.7 (C-3), 39.8 (C-10), 60.3 (OCH3), 70.6 (C-130),
72.9 (CH2Ph), 74.8 (C-2), 117.5 (C-5), 122.9 (C-6), 125.7
(C-7), 127.6 (C-8), 138.8 (Ar-C), 147.8 (C-4a), 149.4 (C-8b).
4.1.32. 2-(15-(Benzyloxy)pentadecyl)-2,5,7,8-tetra-
methyl-3,4-dihydro-2H-chromen-6-yl acetate (11e).
1
Yield 99% (0.11 g). H NMR (300 MHz, CDCl3) d: 1.25
(s, 3H, H-2a), 1.29 (br s, 24H, H-20 to H-130), 1.59 (m, 4H,
H-10, H-140), 1.78 (m, 2H, H-3), 2.11 (s, 6H, H-5a, H-7a),
2.16 (s, 3H, H-8a), 2.34 (s, 3H, CH3C]O), 2.60 (t, 2H,
J 6.8 Hz, H-4), 3.48 (t, 2H, J 6.6 Hz, H-150), 4.52 (s, 2H,
CH2Ph), 7.29 (m, 5H, Ar-H). 13C NMR (75 MHz, CDCl3)
d: 11.3–12.2 (C-5a, C-7a, C-8a, CH3C]O), 20.5 (C-4),
20.6 (C-20), 23.8 (C-2a), 26.2 (C-30), 29.5–30.0 (C-40 to
C-140), 31.5 (C-3), 39.5 (C-10), 70.5 (C-150), 72.9
(CH2Ph), 76.5 (C-2), 117.3 (C-5), 123.1 (C-6), 124.9
(C-7), 126.7 (C-8), 127.7–128.3 (Ar-CH), 138.7 (Ar-C),
140.5 (C-4a), 149.8 (C-8b), 169.8 (C]O).
4.1.36. 2-(14-(Benzyloxy)tetradecyl)-6-methoxy-2,5,7,8-
tetramethyl-3,4-dihydro-2H-chromene (12d). Yield 99%
(0.72 g). 1H NMR (300 MHz, CDCl3) d: 1.24 (s, 3H,
H-2a), 1.27 (br s, 22H, H-20 to H-120), 1.61 (m, 4H, H-10,
H-130), 1.78 (m, 2H, H-3), 2.12 (s, 3H, H-7a), 2.16 (s, 3H,
H-5a), 2.19 (s, 3H, H-8a), 2.58 (t, 2H, J 6.8 Hz, H-4), 3.47
(t, 2H, J 6.6 Hz, H-140), 3.64 (s, 3H, OCH3), 4.51 (s, 2H,
CH2Ph), 7.30 (m, 5H, Ar-H). 13C NMR (75 MHz, CDCl3)
d: 11.7 (C-5a), 11.8 (C-7a), 12.5 (C-8a), 20.7 (C-4), 23.7
(C-20), 23.8 (C-2a), 26.2 (C-30), 29.4–31.3 (C-40 to C-130),
31.7 (C-3), 39.8 (C-10), 60.3 (OCH3), 70.6 (C-140), 72.8
(CH2Ph), 74.8 (C-2), 117.5 (C-5), 122.9 (C-6), 125.7 (C-7),
127.6 (C-8), 138.8 (Ar-C), 147.8 (C-4a), 149.4 (C-8b).
4.1.33. 2-(11-(Benzyloxy)undecyl)-6-methoxy-2,5,7,8-
tetramethyl-3,4-dihydro-2H-chromene (12a). To a solu-
tion of compound 9a (0.53 g, 1.13 mmol, 1 equiv) in dry
THF (12 mL) cooled to 0 ꢁC were added sodium hydride
(0.04 g, 1.58 mmol, 1.4 equiv) and methyl iodide (0.21 mL,
3.39 mmol, 3 equiv). After 1 h at 0 ꢁC, a saturated solution
of NH4Cl (100 mL) was added to the reaction mixture and
the aqueous layer was extracted with ether (3ꢃ100 mL).
The combined organic extracts were dried over MgSO4 and
concentrated under reduced pressure. The residue was
4.1.37. 2-(15-(Benzyloxy)pentadecyl)-6-methoxy-2,5,7,8-
tetramethyl-3,4-dihydro-2H-chromene (12e). Yield 96%
(0.52 g). 1H NMR (300 MHz, CDCl3) d: 1.25 (s, 3H,
H-2a), 1.26 (br s, 24H, H-20 to H-130), 1.60 (m, 4H, H-10,
H-140), 1.78 (m, 2H, H-3), 2.11 (s, 3H, H-7a), 2.16 (s, 3H,
H-5a), 2.20 (s, 3H, H-8a), 2.59 (t, 2H, J 6.8 Hz, H-4), 3.48