K. A. Parker and D.-S. Su
194
combined EtOAc solution was dried over MgSO4 and concentrated. Preparative
TLC (hexanes/EtOAc, 1 : 4) gave 13 mg of aminoglycal 3 (20% recovery) and
1
56 mg (85% based on unrecovered starting material) of a yellow oil: H NMR
(CDCl3): d 7.73 (ddd, J ¼ 9.5, 5.5, 1.6 Hz, 4H), 7.39 (m, 6H), 6.80 (td,
J ¼ 10.3, 3.1 Hz, 2H), 6.19 (dt, J ¼ 7.4, 2.9 Hz, 2H), 4.95 (dd, J ¼ 3.0, 0.7 Hz,
1H), 4.00 (q, J ¼ 5.6 Hz, 1H), 3.78 (t, J ¼ 5.0 Hz, 1H), 2.81 (dd, J ¼ 4.9,
3.1 Hz, 1H), 2.21 (s, 6H), 1.05 (s, 9H), 0.98 (d, J ¼ 6.6 Hz, 3H); 13C NMR
(CDCl3): d 185.4, 150.4, 148.1, 136.1, 136.0, 134.3, 133.7, 129.8, 129.7, 128.5,
128.4, 127.5, 127.4, 94.1, 75.4, 71.4, 57.1, 43.1, 27.0, 19.5, 17.5; FTIR (neat):
3319, 1666 cm21; HRMS (FAB, NaI): calc. 526.2389, found: 526.2393 (M þ Na).
Aminoglycal-substituted Quinol 8b. To
a solution of 121 mg
(0.31 mmol) of aminoglycal 3 in 3 mL of THF at 2788C was added 0.8 mL
(0.94 mmol) of t-BuLi (1.2 M in pentane). The resulting solution was stirred
at 2788C for 5 min and at 08C for 1 hr, then cooled to 2788C and added
dropwise by cannula to a solution of 61 mg (0.39 mmol) of naphthoquinone in
3 mL of THF at 2788C. The blue reaction mixture was stirred at 2788C for
4 hr and 30 min, then diluted with 20 mL of ether and poured into 20 mL of
H2O. The resulting mixture was extracted with ether (4 ꢀ 20 mL), and the
combined ether solution was dried over MgSO4 and concentrated. Preparative
TLC (hexanes/EtOAc, 1 : 4) gave 140 mg (81%) of a brown oil: 1H NMR (CDCl3):
d 8.11 (dd, J ¼ 1.3, 7.7 Hz, 1H), 7.75 (dd, J ¼ 1.0, 7.9 Hz, 1H), 7.65 (dd, J ¼ 1.6,
8.9 Hz, 2H), 7.42 (m, 8H), 7.14 (d, J ¼ 7.1 Hz, 2H), 6.84 (d, J ¼ 10.2, 1H), 6.37
(d, J ¼ 10.1, 1H), 5.22 (t, J ¼ 1.1 Hz, 1H), 3.80 (dd, J ¼ 4.3, 6.7 Hz, 1H), 3.62
(t, J ¼ 3.6 Hz, 1H), 2.78 (dd, J ¼ 2.3, 4.4 Hz, 1H), 2.12 (s, 6H), 0.96 (s, 9H),
0.83 (d, J ¼ 6.7 Hz, 3H); 13C NMR (CDCl3): d 184.9, 152.3, 149.7, 144.4,
136.2, 135.8, 134.2, 133.3, 133.1, 130.7, 129.7, 129.5, 128.6, 128.3, 127.5,
127.3, 127.2, 126.1, 93.4, 75.1, 70.6, 57.0, 42.8, 27.0, 19.3, 16.9; FTIR (neat):
3380, 1666, 1600 cm21; HRMS (FAB, NaI): calcd. 576.2546, found: 576.2543
(M þ Na).
Ferrier-rearrangement Product 10. To
a
solution of 17 mg
(0.034 mmol) of glycal-substituted quinol 8a in 1 mL of THF/H2O (9/1) was
added 7.7 mg (0.29 mmol) of amalgamated aluminum foil (formed by immersion
in 2% aqueous HgCl2, washing with EtOH, then Et2O).[11] The solution was
stirred at rt for 2 hr, filtered through a pad of Celite, and concentrated. Pre-
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parative TLC (MeOH/CHCl3, 1 : 9) gave 10 mg (67%) of a yellow oil: H NMR
(CDCl3): d 7.53 (m, 4H), 7.25 (m, 8H), 6.77 (dd, J ¼ 2.0, 6.8 Hz, 2H), 6.63
(d, J ¼ 11.8 Hz, 1H), 6.16 (dd, J ¼ 8.6, 10.8 Hz, 1H), 4.96 (dd, J ¼ 3.5, 8.5 Hz,
1H), 3.90 (m, 1H), 3.39 (m, 1H), 1.23 (d, J ¼ 6.3 Hz, 3H), 1.04 (s, 9H); 13C
NMR (CDCl3): d 147.0, 135.8, 135.7, 131.3, 129.7, 129.6, 127.6, 127.5, 125.5,
115.2, 74.6, 71.1, 27.0, 19.3, 19.1; FTIR (neat): 3252, 1591 cm21; HRMS (FAB,
NaI): calcd. 483.1967, found: 483.1957 (M þ Na).