1.4, 8.7 Hz, 1H), 7.41 (s, 1H), 7.84–7.88 (m, 2H); 13C NMR
(CDCl3, 50 MHz) δ: 19.6, 21.8, 56.9, 73.0, 87.5, 119.1, 121.9,
124.0, 124.2, 125.9, 127.8, 130.5, 131.9, 133.5, 133.7, 134.0,
134.1, 135.1; HRMS (ESI) m/z [M
C19H22O2Na: 305.1517, found: 305.1518.
Acknowledgements
This work was supported by DST & CSIR, Government of
India. P.M. is grateful to CSIR, Government of India for a Senior
Research Fellowship. We are also thankful to Prof. S. Ghosh
(IACS, Kolkata) and Prof. Balaram Mukhopadhyay (IISER,
Kolkata) for help with spectral data. DST is thanked for the cre-
ation of a 400MHz NMR facility under the IRPHA program.
+
Na]+ calcd for
2-Methoxy-6,9-dimethyl-1,2-dihydrophenanthren-1-ol (22)
Grubbs II catalyst (10 mol%) was added to a degassed solution
(N2) of 21 (0.25 mmol) in benzene (2.5 mL). The reaction
mixture was stirred at rt for 5 h. Volatiles were then removed
under reduced pressure. The residue was then flash-chromato-
graphed on a silica gel column to yield 22 (51 mg, 80%) as a
white solid. Rf = 0.25 (Petroleum ether : ethyl acetate, 8.5 : 1.5);
mp: 142–144 °C; [α]2D8.6 = −281.08 (c 0.65, DCM); IR (KBr,
cm−1) 3281, 2812, 1626, 1514, 1485, 1435, 1286, 1114, 1097,
Notes and references
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G. Candiani, Fitoterapia, 2003, 74, 323, and references cited therein
(b) S. Penco, WO 0168071, 2001.
1
1049, 977, 900, 806, 725, 640; H NMR (CDCl3, 200 MHz) δ:
3 M. A. Shushni, R. Mentel, U. Lindequist and R. Jancen, Chem. Biodiver-
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2.54 (s, 3H), 2.69 (s, 3H), 3.54 (s, 3H), 4.14–4.19 (m, 1H), 5.01
(d, J = 10.8 Hz, 1H), 6.22 (dd, J = 2.0, 10.2 Hz, 1H), 7.23–7.37
(m, 2H), 7.58 (s, 1H), 7.87–7.92 (m, 2H); 13C NMR (CDCl3,
50 MHz) δ: 19.7, 21.9, 56.7, 73.1, 82.0, 122.4, 123.1, 123.9,
124.5, 126.3, 127.6, 129.7, 130.5, 133.3, 134.6, 135.6; HRMS
(ESI) m/z [M + Na]+ calcd for C17H18O2Na: 277.1204, found:
277.1206.
4 (a) S. R. Peraza-Sanchez, D. Chavez, H. B. Chai, Y. G. Shin, R. Garcia,
M. Mejia, C. R. Fairchild, K. E. Lane, A. T. Menendez, N.
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5 G. Dyker and D. Hildebrandt, J. Org. Chem., 2005, 70, 6093.
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1-Hydroxy-2-methoxy-6,9-dimethyl-2,3-dihydro-1H-
phenanthren-4-one (1)
7 I. S. Young and P. S. Baran, Nat. Chem., 2009, 1, 193.
8 H. C. Brown, P. K. Jadhav and K. S. Bhat, J. Am. Chem. Soc., 1988, 110,
1535.
22 (0.1 mmol) was added to a stirred solution of PdCl2 (10 mol
%) and CuCl (1.1 equiv.) in DMF and H2O (1.2 mL, 9 : 1) under
oxygen atmosphere. The resulting dark brown solution was
stirred vigorously for 6 h at 50 °C and then extracted with ether.
The organic layer was washed with brine, dried over anhydrous
Na2SO4 and solvent was evaporated under reduced pressure. The
residue was then purified by flash chromatography to afford 1
(19 mg, 70%).
9 Enantiomeric excess (ee) of 8 and 21 was determined by 19F NMR analy-
sis and for 15 by high field 1H NMR analysis of the corresponding
Mosher esters see: V. J. Davisson and C. D. Poulter, J. Am. Chem. Soc.,
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10 (a) J. Tsuji, Synthesis, 1984, 369; (b) T. Mitsudome, K. Mizumoto,
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13 P. R. Skaanderup and R. Madsen, J. Org. Chem., 2003, 68, 2115.
14 For heteroatom-directed Wacker oxidation in an acyclic system, in the
context of a total synthesis, see: P. J. Choi, J. Sperry and M. A. Brimble,
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Rf
= 0.22 (Petroleum ether : ethyl acetate, 1 : 2); mp:
170–172 °C; [α]D26.2 = −19.1 (c 0.28, MeOH); lit.1 [α]2D5 = −10.8
(c 0.6, MeOH) IR (neat, cm−1) 3308, 2966, 1660, 1593, 1240,
1126, 1099, 1084, 1051, 979, 904, 815; H NMR (400 MHz,
1
15 P. Mukherjee, S. J. S. Roy and T. K. Sarkar, Org. Lett., 2010, 12, 2472.
16 For regioselective Wacker oxidation of acetonide protected internal allylic
olefins, Kang et al. presumed simultaneous chelation of palladium with
CDCl3) δ 2.56 (s, 3H), 2.65 (dd, J = 10.8, 16.2 Hz, 1H), 2.75 (s,
3H), 3.08 (s, 1H), 3.30 (dd, J = 4.4, 16.0 Hz, 1H), 3.51 (s, 3H),
3.71 (ddd, J = 4.8, 7.6, 11.6, 1H), 4.91 (d, J = 8.4 Hz, 1H), 7.41
(d, J = 8.4 Hz, 1H), 7.70 (s, 1H), 7.93 (d, J = 8.4 Hz, 1H), 9.27
(s, 1H); 1H NMR (400 MHz, acetone-d6) δ 2.52 (s, 3H),
2.67–2.79 (m, 1H), 2.73 (s, 3H), 3.21 (dd, J = 4.0, 16.0 Hz, 1H),
3.45 (s, 3H), 3.78–3.82 (m, 1H), 4.90 (t, J = 6.0 Hz, 1H), 4.98
(d, J = 5.2 Hz, 1H), 7.43 (d, J = 8.4 Hz, 1H), 7.63 (s, 1H), 7.99
(d, J = 8.4 Hz, 1H), 9.32 (s, 1H); 13C NMR (100 MHz, acetone-
d6) δ 20.3, 22.2, 43.4, 57.2, 72.1, 81.4, 124.9, 125.0, 126.8,
127.2, 128.9, 131.6, 131.9, 138.8, 142.4, 146.2, 197.8; HRMS
(ESI) m/z [M + Na]+ calcd for C17H18O3Na: 293.1154, found:
293.1154.
two neighbouring oxygen atoms17
.
17 S. K. Kang, K. Y. Jung, J. U. Chung, E. Y. Namkoong and T. H. Kim, J.
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20 An anti-selective Duthaler–Hafner oxyallylation reaction21 involving an
alkoxyallyltitanium species might deliver 15 from 7 in one step with
higher enantioselectivity compared to our three-step sequence from alde-
hyde 7; this work is under way in this laboratory.
21 A. Hafner, R. O. Duthaler, R. Marti, G. Rihs, P. Rothe-Streit and
F. Schwarzenbach, J. Am. Chem. Soc., 1992, 114, 2321.
22 D. D. Phillips, J. Am. Chem. Soc., 1955, 77, 3658.
23 T. Gaich and P. S. Baran, J. Org. Chem., 2010, 75, 4657.
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