6282
R.A. Aitken et al. / Tetrahedron 73 (2017) 6275e6285
C-1), 133.9 (d, J ¼ 5; Ph C-2); 133.6 (d, J ¼ 10 Hz; PPh C-2), 133.2
(Ar C-5), 131.8 (d, J ¼ 12 Hz; Ph C-1), 131.4 (d, J ¼ 3 Hz; PPh C-4),
129.9 (Ph C-4),128.4 (d, J ¼ 12 Hz; PPh C-3),126.7 (d, J ¼ 2 Hz; Ph
C-3), 126.6 (d, J ¼ 91 Hz; PPh C-1), 124.3 (d, J ¼ 2 Hz; Ar C-6),
119.8 (Ar C-4), 111.1 (Ar C-3), 74.0 (d, J ¼ 107 Hz; P]C), 55.4 ppm
Data were recorded at 293(2) K on a Bruker SMART diffractometer
using Mo-K radiation and the structures were solved by direct
a
methods and refined using full-matrix least squares analysis. The
following crystal data were obtained: C23H21O3P, M ¼ 376.37, col-
ourless prism, monoclinic space group P21/n; a ¼ 12.00380(10),
(OMe); 31P NMR:
d
¼ þ15.2 ppm; elemental analysis calcd (%)
b
¼
9.02880(10),
c
¼
19.0573(3) Å,
b
¼
106.6540(10)ꢀ,
V ¼ 1978.79(4) Å3, Z ¼ 4, Dc ¼ 1.263 g cmꢁ3, R ¼ 0.0356,
for C33H26ClO2P: C 76.07, H 5.03; found: C 76.02, H 4.96.
1 (R1 ¼ 2-MeOC6H4, R2 ¼ 2-MeSC6H4)66
d
¼ 185.6 (d, J ¼ 6.1 Hz;
RW ¼ 0.0940 for 2423 data with with I > 2
s(I) and 245 parameters.
CO), 157.9 (d, J ¼ 3 Hz; CeOMe),142.9 (d, J ¼ 12 Hz; Ar C-1),136.5
(d, J ¼ 6 Hz), 136.4 (CeSMe), 133.6 (d, J ¼ 10 Hz; Ph C-2), 131.1 (d,
J ¼ 3 Hz; Ph C-4), 128.0 (d, J ¼ 12 Hz; Ph C-3), 127.8 (Ar CH), 127.3
(Ar CH), 127.2 (d, J ¼ 2 Hz; Ar CH), 126.9 (d, J ¼ 91 Hz; Ph C-1),
126.9 (d, J ¼ 10 Hz; Ar C-1), 126.1 (Ar CH), 123.7 (Ar CH), 119.9 (d,
J ¼ 1 Hz; Ar CH),109.2 (d, J ¼ 2 Hz; Ar CH), 67.8 (d, J ¼ 109 Hz; P]
C), 54.0 (OMe), 17.0 ppm (SMe).
4.2.6. 1-(2-methoxyphenyl)-3-phenyl-3-
triphenylphosphoranylidenepropane-1,2-dione (31)
This was prepared using the published method58 as yellow
crystals directly suitable for X-ray diffraction. Data were recorded at
93(2) K on a Rigaku Mercury 70 diffractometer using Mo-Ka radi-
ation and the structures were solved by direct methods and refined
using full-matrix least squares analysis The following crystal data
were obtained: C34H27O3P, M ¼ 514.53, triclinic space group Pe1;
4.4. Preparation of cyclic ylides
a ¼ 9.828(2), b ¼ 10.622(3), c ¼ 13.692(2) Å,
a
¼ 74.94(2),
2,
b
¼
73.96(2),
g
¼
78.45(2)ꢀ,
V
¼
1313.7(5) Å3,
Z
¼
Dc ¼ 1.301 g cmꢁ3, R ¼ 0.0579, Rw ¼ 0.1550 for 2874 data with
Preparation of ylides 35e37 was carried out in four steps
following the reported procedure.82 The appropriate
u-bromo-
I > 2s(I) and 343 parameters.
carboxylic acid (0.1 mol) was converted to the ethyl ester by
boiling in ethanol (100 cm3) in the presence of H2SO4 (0.1 cm3) for
3 h. The solution was evaporated and the residue dissolved
directly in A.R. acetone (50 cm3). To this was added a solution of
sodium iodide (18.0 g, 0.12 mol) in A.R. acetone (50 cm3). After
stirring at RT for 12 h the mixture was evaporated and the residue
partitioned between toluene (100 cm3) and water. The toluene
layer containing the iodoester was dried and triphenylphosphine
(26.2 g, 0.1 mol) added. This solution was heated under reflux for
12 h and, after cooling, the supernatant liquid was decanted off
from the lower oily layer of the phosphonium salt which was
washed twice with toluene by decantation. The salt was then
dissolved in t-butanol (150 cm3), potassium t-butoxide (11.0 g,
97 mmol) was added and the solution heated under reflux for
12 h. The resulting mixture was evaporated and the residue par-
titioned between CH2Cl2 and water. Drying and evaporation of the
organic phase gave the desired ylide, which was recrystallised
from ethyl acetate.
4.2.7. Methyl 2,4-dioxo-3-triphenylphosphoranylidenepentanoate
(32)
This was prepared as previously described.21 A purple prism
suitable for X-ray diffraction was obtained by recrystallisation from
ethyl acetate. Data were recorded at 293(2) K on a Bruker SMART
diffractometer using Mo-Ka radiation and the structure was solved
by direct methods and refined using full-matrix least squares
analysis. The following crystal data were obtained: C24H21O4P,
M ¼ 404.38, monoclinic space group P21/c; a ¼ 12.7684(5),
b ¼ 9.1236(3), c ¼ 17.6495(6) Å,
b
¼ 92.291(1)ꢀ, V ¼ 2054.41(13) Å3,
Z ¼ 4, Dc ¼ 1.307 g cmꢁ3, R ¼ 0.032, Rw ¼ 0.079 for 2454 data with
I > 2s(I) and 263 parameters.
4.3. Representative 13C NMR data for ylides in Table 2
1 (R1 ¼ Me, R2 ¼ H)51
d
¼ 178.5 (d, J ¼ 26 Hz; CO), 133.1 (d,
J ¼ 10 Hz; Ph C-2), 132.3 (d, J ¼ 2 Hz; Ph C-4), 128.5 (d, J ¼ 12 Hz;
Ph C-3), 123.8 (d, J ¼ 88 Hz; Ph C-1), 62.2 (d, J ¼ 110 Hz; P]C),
10.2 ppm (d, J ¼ 11 Hz; CH3).
4.4.1. 2-Triphenylphosphoranylidenecyclopentanone (35)
Colourless crystals (25%), m.p. 221e223 ꢀC (lit.89 229e233 ꢀC);
1 (R1 ¼ H, R2 ¼ But)71
¼ 199.9 (s, CO), 132.7 (d, J ¼ 10 Hz; Ph C-2),
d
131.4 (d, J ¼ 2 Hz; Ph C-4), 128.4 (d, J ¼ 12 Hz; Ph C-3), 127.6 (d,
J ¼ 91 Hz; Ph C-1), 47.0 (d, J ¼ 110 Hz; P]C), 40.3 (d, J ¼ 12 Hz;
C), 28.6 ppm (3 CH3).
1H NMR:
d
¼ 7.8e7.3 (m, 15H), 2.6e1.9 ppm (m, 6H); 13C NMR:
d
¼ 196.1 (d, J ¼ 11.3 Hz; CO), 133.6 (d, J ¼ 10; Ph C-2), 132.2 (d,
J ¼ 3 Hz; Ph C-4), 128.9 (d, J ¼ 12 Hz; Ph C-3), 126.0 (d, J ¼ 90 Hz; Ph
C-1), 56.3 (d, J ¼ 107 Hz; P]C), 40.1 (d, J ¼ 16 Hz; C-5), 31.5 (d,
J ¼ 14 Hz; C-4), 23.7 ppm (d, J ¼ 14 Hz; C-3); 31P NMR:
1 (R1 ¼ Pr, R2 ¼ But)71
¼ 193.4 (s, CO), 132.9 (d, J ¼ 9 Hz; Ph C-2),
d
130.4 (d, J ¼ 2 Hz; Ph C-4), 128.0 (d, J ¼ 12 Hz; Ph C-3), 129.8 (d,
J ¼ 96 Hz; Ph C-1), 68.2 (d, J ¼ 105 Hz; P]C), 39.8 (d, J ¼ 11 Hz;
C), 29.1 (d, J ¼ 12 Hz, CH2), 28.6 (3 CH3), 28.2 (CH2), 13.6 ppm
(CH3).
d
¼ þ12.6 ppm.
4.4.2. 2-Triphenylphosphoranylidenecyclohexanone (36)
1 (R1 ¼ Pr, R2 ¼ c-Hex)71
d
¼ 193.5 (s, CO), 133.2 (d, J ¼ 9 Hz; Ph C-
Colourless crystals (38%), m.p. 248e250 ꢀC (lit.,82 245e247 ꢀC);
2), 130.9 (d, J ¼ 1 Hz; Ph C-4), 128.1 (d, J ¼ 12 Hz; Ph C-3), 128.3
(d, J ¼ 90 Hz; Ph C-1), 63.9 (d, J ¼ 103 Hz; P]C), 43.3 (d,
J ¼ 10 Hz; CH), 29.9 (2 CH2), 29.0 (d, J ¼ 14 Hz; CH2), 28.1 (CH2),
26.4 (2 CH2), 26.1 (CH2), 13.6 ppm (CH3).
1H NMR:
13C NMR:
d
¼ 7.8e7.3 (m, 15H), 2.25 (m, 2H), 2.0e1.6 ppm (m, 6H);
d
¼ 187.7 (d, J ¼ 3.7 Hz; CO), 133.2 (d, J ¼ 10; Ph C-2), 131.1
(d, J ¼ 2 Hz; Ph C-4), 128.1 (d, J ¼ 12 Hz; Ph C-3), 126.7 (d, J ¼ 89 Hz;
Ph C-1), 58.9 (d, J ¼ 101 Hz; P]C), 36.2 (d, J ¼ 10 Hz; C-6), 26.4 (d,
J ¼ 11 Hz; C-3/4), 25.1 (d, J ¼ 11 Hz; C-3/4), 23.9 ppm (C-5); 31P
1 (R1 ¼ Pri, R2 ¼ 2-MeOC6H4)74
¼ 184.5 (d, J ¼ 5.3 Hz; CO), 156.0
d
(Ar C-2), 134.1 (d, J ¼ 13 Hz; Ar C-1), 133.6 (d, J ¼ 10 Hz; Ph C-2),
131.0 (d, J ¼ 3 Hz; Ph C-4), 128.3 (d, J ¼ 12 Hz; Ph C-3), 128.3 (Ar
CH), 128.2 (d, J ¼ 90 Hz; Ph C-1), 127.9 (Ar CH), 120.0 (Ar CH),
110.7 (Ar CH), 75.5 (d, J ¼ 98 Hz; P]C), 55.6 (OMe), 27.5 (d,
J ¼ 13 Hz; CHMe2), 24.7 ppm (br; CHMe2).
NMR:
d
¼ þ17.4 ppm.
4.4.3. 2-Triphenylphosphoranylidenecycloheptanone (37)
Colourless crystals (20%), m.p. 205e206 ꢀC (lit.,82 205e208 ꢀC);
1H NMR:
8H); 13C NMR:
d
¼ 7.8e7.3 (m, 15H), 2.7e2.4 (m, 2H), 2.0e1.3 ppm (m,
1 (R1 ¼ Ph, R2 ¼ 2-MeO-5-ClC6H3) mp 212e214 ꢀC; 1H NMR:
d
¼ 195.3 (d, J ¼ 4.2 Hz; CO), 133.4 (d, J ¼ 10; Ph C-2),
d
¼ 7.80e7.30 (m, 15H; PPh), 7.18 (d, J ¼ 8 Hz,1H; Ar), 6.78 (s, 5H;
131.3 (d, J ¼ 2 Hz; Ph C-4), 128.5 (d, J ¼ 12 Hz; Ph C-3), 127.7 (d,
J ¼ 90 Hz; Ph C-1), 63.6 (d, J ¼ 105 Hz; P]C), 42.9 (d, J ¼ 12 Hz; C-7),
32.6 (C-5/6), 32.4 (d, J ¼ 4 Hz; C4), 26.9 (d, J ¼ 13 Hz; C-3), 25.5 ppm
CPh), 6.70e6.55 (m, 2H,; Ar), 3.62 ppm (s, 3H; OMe); 13C NMR:
¼ 184.0 (d, J ¼ 6.7 Hz; CO),156.5 (Ar C-2), 137.4 (d, J ¼ 12 Hz; Ar
d