References
1 Franck-Neumann M.
Geoffroy P.
Winling A.
Synlett
1995,
341
2 The phenols are more difficult to observe
(TLC) and to isolate than the very polar and essentially non-volatile cyclohexadienone
complexes. However, they could be isolated as Boc-protected phenols,
when Boc2 O/DMAP was added immediately after
thermolysis, these reagents achieving not only protection,
[13
3 The complex 7 was
obtained by complexation [71%, Fe2 (CO)9 ,
benzene, 60 °C] of the crotonization
product of cyclohexene-1-carboxaldehyde-1 with acetone (63%, NaOH/H2 O).
4 Cais M.
Maoz N.
J. Organomet. Chem.
1966,
5:
370
5 Salzer A.
Schmalle H.
Stauber R.
Streiff S.
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1991,
408:
403
6 The details of the X-ray structure
(Figure
[1
Figure 1 Ortep view of 13a (mp 100 °C).
Typical Experimental
Procedure:
7a
Tosylhydrazone 12 : A solution of the complexed β-ionone 11 [2.00 g, 6.0 mmol, from β-ionone
(1.90 g) and diironnonacarbonyl (3.50 g)], tosylhydrazine
(1.20 g, 6.4 mmol) and p -toluenesulfonic acid
(0.15 g, 0.8 mmol) in dimethoxyethane (50 mL) was stirred at room
temperature for 24 h. Diethyl ether (75 mL) was added and the solution
was washed with saturated aqueous solutions of NaHCO3 and
NaCl, and dried with MgSO4 . The solvents were removed
by evaporation (30 °C, 15 Torr) and the residue
was purified by chromatography on a silica gel column (90 g, Merck
Si60, eluent hexane with 30% CH2 Cl2 ).
2.20 g tosylhydrazone 12 (C23 H28 N2 O5 S
Fe, 4.4 mmol, 73%, yellow crystals, mp 170 °C)
were obtained.
7b
Cyclocarbonylation :
NaH (40 mg, 1.7 mmol) was added to a stirred solution of the tosylhydrazone 12 (600 mg, 1.2 mmol) in mesitylene (50
mL). Cu(acac)2 (31 mg, 0.12 mmol) was added and the air
atmosphere over the mixture was replaced by carbon monoxide (several
degassings under reduced pressure). The temperature was gradually
raised from room temperature to 110 °C in 30 min
and kept at 110 °C for further 20 min. About 80% of
the solvent was evaporated (30 °C, 0.1 Torr),
and the resulting solution was chromatographed on SiO2 (60
g, eluent hexane with 0% to 40% diethyl ether).
128 mg cyclohexadienone complex 13a (0.37
mmol, 31%) were obtained.Cyclohexadienone
complex 13a : yellow crystals, mp 100 °C;
Anal. calcd for C17 H20 O4 Fe: C,
59.29; H, 5.86. Found: C, 59.28; H, 6.08; IR (CCl4 ) νmax 2050,
1990, 1979, 1651 cm-1 ; 1 H
NMR (200 MHz, C6 D6 ) δ 0.64 (s, 3
H), 0.84 (s, 3 H), 0.91 (s, 3 H), 1.11-1.45 (mm, 4 H),
1.52 (s, 3 H), 1.99 (m, 2 H), 4.64 (d, J = 5.0
Hz, 1 H), 4.88 (d, J = 5.0 Hz, 1 H); 13 C
NMR (50 MHz, CDCl3 ) δ 17.48, 17.80, 31.48, 35.29,
36.58, 39.56, 43.14, 71.03, 81.75, 83.83, 101.57, 191.68.
8a Mossetig E.
Stuart AH.
J. Am. Chem. Soc.
1939,
61:
1
8b Chan T.-H.
Brownbridge P.
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1980,
102:
3534
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Synthesis
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Geoffroy P.
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1994,
35:
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11 Franck-Neumann M.
Martina D.
Brion F.
Angew.
Chem., Int. Ed. Engl.
1978,
17:
690 ; Angew. Chem . 1978 , 90 , 737
12 The cyclohexadienone 23 has
been prepared for the synthesis of herbertene,
[14 4 -octalin and
with an overall yield of 5.3%. Another synthesis in 5 steps
from β-ionone was reported, however without any indication
of yields.
[15
13 Hansen MM.
Riggs JR.
Tetrahedron Lett.
1998,
39:
2705
14a Banerjee AK.
Pena-Matheud CA.
de Carrasco MC.
J.
Chem. Soc., Perkin Trans. 1
1988,
2485
14b Dauben WG.
Ashcraft AC.
J.
Am. Chem. Soc.
1963,
85:
3673
15 Khodabocus A.
Shing TKM.
Sutherland JK.
Williams JG.
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