180
T.I. Odiaka et al. / Journal of Organometallic Chemistry 761 (2014) 179e189
3. Equation for adduct formation
Reflux, 110OC
+
H+
Fe(CO)3
NuH
+
Fe(CO)3
+
...........(1)
dry toluene, N2
Nu
whereNuH=Gedunin/khivorin/7-ketokhivorin/polyavolensinol
where NuH
sinol
¼
gedunin/khivorin/7-ketokhivorin/polyavolen
3.1.2.1. C41H48O13Fe. Yellow oil, IR (film) Vmax cmꢁ1 ¼ 2962 (CeH str
of alkanes), 2050 & 1980 (O(CO) bands of coordinated diene of
organometallic moiety), 1730 (C]O str ester), 1256, 1083 & 1013
(CeO str ester), 873 (furan band), 563 (FeeC band). EMS m/z
(relative intensity %): MS (804.8), 173 (2.27) [M ꢁ (2CO) ꢁ
(C31H41O10) ꢁ (2Hþ)], 355 (1.135) [M ꢁ (2CO) ꢁ (C22H34O6) þ (Hþ)],
541 (5)[M ꢁ (2CO) ꢁ (C9H10O2Fe) ꢁ (Hþ)], 609 (100) base peak [M-
(2CO) ꢁ (C5H5OFe) ꢁ (2Hþ)], 625 (2.27) [M ꢁ (2CO) ꢁ (C4H3OFe)],
687 (1.135) [M ꢁ (2CO) ꢁ (C2H3O2) ꢁ (2Hþ)]. 1H NMR (CDCl3,
3.1. Products isolation and characterization
This was carried out using the method described by Odiaka
et al. [16].
3.1.1. Tricarbonyl [1-4-
h
-5-(gedunino)cyclohexa-1,3-diene]iron (II)
-C6H7)(CO)3][BF4] and a two-
400 MHz
d
ppm): 4.55 (1H, m, H1), 1.41 (2H, dd, H2a&2b), 4.45 (1H,
(0.05 g, 0.1634 mmol) of [Fe (1-5-
h
m, H3), 2.12 (1H, m, H5), 2.16 ( 1H, m, H6b), 4.64 (1H, m, H7), 1.38
(1H, m, H11a), 1.85 (1H, m, H11b), 1.88 (1H, m, H12a), 1.57 (1H, m,
H12b), 1.57 (1H, m, H12b), 3.45 (1H, s, H15), 1.17 (3H, s, H18), 0.74 (3H,
s, H19), 6.24 (1H, s, H21), 5.54 (1H, s, H22), 0.85 (3H, s, H28), 1.01 (3H,
s, H29), 0.94 (3H, s, H30), 2.08 (3H, s, H320 ), 1.95 (3H, s, H330), 1.49 (3H,
fold molar excess of gedunin (0.157 g, 0.3268 mmol) was refluxed in
a three-necked round-bottom flask (50 cm3) under nitrogen in
30 ml dry toluene at 110 ꢀC for 48 h. The mixture was allowed to
cool to room temperature and then concentrated using rotary
evaporator under reduced pressure to give a light yellow solid. This
solid was shaken with (20/20, v/v) diethylether/water. The aqueous
layer was set aside while the organic layer was concentrated using
rotary evaporator under reduced pressure to give yellow oil. This
was dried in a vacuum line for 3 h to give the same yellow oil
(0.04 g, 35% yield). The IR O(CO) bands were observed at 2045 and
s, H34), 7.33 (1H, d, H3’), 2.79 (1H, m, H2 ), 1.60 (1H, m, H6 a) and 2.19
0
(1H, m, H6 b).
3.1.3. Tricarbonyl[1,4-
iron (IV)
h
-5-(7-ketokhivorino)cyclohexa-1,3-diene]
-C6H7)(CO)3][BF4] was
1970 cmꢁ1
.
(0.025 g, 0.0817 mmol) of [Fe (1-5-
h
weighed into the flask followed by the addition of a two-fold excess
of 7-ketokhivorin (0.0907 g, 0.1634 mmol). This was refluxed in
25 ml dry toluene for 48 h, followed by a similar work-up as for
gedunin above which resulted into a yellow solid after drying on a
vacuum line for 4 h. The yield, obtained was (0.028 g (44%)). The IR
O(CO) band were observed at 2050 and 1980 cmꢁ1. Spectra data of
the products are presented thus.
3.1.1.1. C37H40O10Fe. Yellow oil, IR (film) Vmax cmꢁ1 ¼ 2962 (CeH str
of alkanes), 2045 & 1970 (O(CO) bands of coordinated diene of
organometallic moiety), 1738 (C]O str of esters), 1667 (ab-unsat-
urated ketone), 1495 (CeC band of C6H7), 1368 & 1163 (CeO str of
esters), 874 (furan band) and 563 (FeeC band). EMS m/z (relative
intensity%): MS (700.7), 109 (8.125) [M ꢁ (2CO) ꢁ (C32H39O7)], 150
(1.825) [M ꢁ (2CO) ꢁ (C25H26O7Fe)], 201 (1.825) [M ꢁ (2CO)-
(C25H31O7)], 257 (6.25) [M ꢁ (2CO) ꢁ (C23H29O5) ꢁ (2Hþ)], 401
(6.25) [M ꢁ (2CO) ꢁ (C12H10O2Fe) ꢁ (Hþ)], 500 (16.25) [M ꢁ (2CO) ꢁ
3.1.3.1. C39H44O12Fe. Yellow solid, IR (film) Vmax cmꢁ1 ¼ 2962 (CeH
str of alkanes), 2050 & 1980 (O(CO) band of coordinated diene of
organometallic moiety), 1728 (C]O str of ester), 1256, 1084 & 1012
(CeO str of ester), 873 (furan band), 565 (FeeC band). EMS m/z
(relative intensity%): MS (760.73), 191 (1.704) [M ꢁ (2CO) ꢁ
(C29H37O8)], 219 (2.840) [M ꢁ (2CO) ꢁ (C27H35 ꢁ O8) þ (2Hþ)], 541
(3.977) [M ꢁ (2CO) ꢁ (C7H7OFe)], 560 (1.704) [M ꢁ (2CO) ꢁ
(C3H3O3Fe)], 593 (3.977) [M ꢁ (2CO) ꢁ (C3H2OFe) ꢁ (Hþ)], 609
(100) base peak [M ꢁ (2CO) ꢁ (C2HOFe) þ (2Hþ)]. 1H NMR (CDCl3,
(C3H3O3Fe)
ꢁ
(Hþ)], 505 (100) base peak [M
ꢁ
(2CO)
ꢁ
(C5H5OFe) ꢁ (2Hþ)], 547 (8.125) [M ꢁ (2CO) ꢁ (C2HOFe)], 546 (35)
[M ꢁ (2CO) ꢁ (OHFe) ꢁ (Hþ)], 604 (3.125) [M ꢁ (2CO) ꢁ
(C2HO)þ(Hþ)]. 1H NMR (CDCl3, 400 MHz
d ppm) see Table 1
3.1.2. Tricarbonyl[1,4-
h
-5-(khivorino)cyclohexa-1,3-diene]iron (III)
-C6H7)(CO)3][BF4] was
(0.025 g, 0.0817 mmol) of [Fe (1-5-
h
weighed into the flask and a two-fold molar excess of khivorin
(0.096 g, 0.1634 mmol) was added and refluxed in a three-necked
round-bottom flask (50 cm3) under nitrogen in 30 ml dry toluene
at 110 ꢀC for 48 h followed by similar work-up as for gedunin above.
This gave yellow oil (0.024 g, 36% yield) which was dried on a
vacuum line for 3 h. The IR O(CO) bands were observed at 2050 and
1980 cmꢁ1. The spectroscopic assignments for the products are
reported below.
400 MHz, d
ppm): 4.65 (1H, t, H1), 1.64 (1H, d, H2a), 1.95 (1H, d, H2b),
4.55 (1H, t, H3), 2.12 (1H, t, H5), 1.92 (1H, t, H6a), 1.55 (1H, s, H6b),
4.45 (1H, t, H9), 1.50 (1H, s, H11a), 1.88 (1H, t, H11b), 2.16 (1H, d, H12a),
1.57 (1H, t, H12b), 3.45 (1H, s, H15), 5.53 (1H, s, H17), 0.94 (3H, s, H18),
0.74 (3H, s, H19), 7.17 (1H, s, H21), 7.12 (1H, s, H22), 2.08 (3H, s, H250),
2.29 (3H, s, H260 ), 1.01 (3H, s, H28), 0.85 (3H,s, H29), 7.33 (1H, m, H1 ),
0
0
7.34 (1H, t, H2 ), 6.24 (1H, dd, H3 ), 2.79 (1H, dd, H5 ), 1.60 (1H, d,
0
0
H6 a) and 2.19 (1H, d, H6 b).