PAPER
Studies on the Synthesis of Richardianidin-1
3699
13C NMR (CDCl3): d = 19.52, 20.48, 22.62, 57.64, 72.49, 94.85,
Pentacarbonyl{(4-hydroxy-2,6-dimethylphenyl)[(4-methyl-
pent-4-en-2-ynyloxy)methoxy]methylene}chromium(0) (54e)
Chloromethyl 4-Methylpent-4-en-2-ynyl Ether (56e)
The chloromethyl ether 56e was prepared from 4-methylpent-4-en-
2-yn-1-ol (384 mg, 4.00 mmol) according to the typical procedure.
1H NMR (CDCl3): d = 1.87 (s, 3 H), 4.48 (s, 2 H), 5.26 (s, 1 H), 5.32
(s, 1 H), 5.57 (s, 2 H).
96.95, 114.93, 128.69, 144.30, 155.18, 216.24, 224.56, 365.33.
MS m/z (%) = 452 [M+] (0.03), 312 [M+ – 5 CO] (2), 187 (30), 180
(15), 149 (100), 121 (30), 91 (15), 90 (18), 80 (27), 79 (19), 77 (31),
53 (16), 52 (42).
Pentacarbonyl{[(1-ethylhex-2-ynyloxy)methoxy](4-hydroxy-
2,6-dimethylphenyl)methylene}chromium(0) (54d)
Chloromethyl 1-Ethylhex-2-ynyl Ether (56d)
The chloromethyl ether 56d was prepared from oct-4-yn-3-ol (315
mg, 2.50 mmol) according to the typical procedure.
{[4-(tert-Butyldimethylsiloxy)-2,6-dimethylphenyl][(4-methyl-
pent-4-en-2-ynyloxy)methoxy]methylene}pentacarbonylchro-
mium(0) (55e)
The carbene complex 55e was prepared from the salt 31 (1.34 g,
2.50 mmol) and chloromethyl ether 56e as a red oil; yield: 919 mg
(65%); Rf = 0.24 (hexane–CH2Cl2, 9:1).
1H NMR (CDCl3): d = 0.97 (t, J = 7.4 Hz, 3 H), 0.98 (t, J = 7.1 Hz,
3 H), 1.52 (m, 2 H), 1.72 (m, 2 H), 2.19 (td, J = 7.2, 1.9, 2 H Hz),
4.46 (t, J = 6.3 Hz, 1 H), 5.56 (d, J = 5.4 Hz, 1 H), 5.72 (d, J = 5.4
Hz, 1 H).
IR (neat): 2957 w, 2932 w, 2220 vw, 2064 s, 1940 s, 1601 w, 1315
w, 1155 w, 841 m, 653 m cm–1.
{[4-(tert-Butyldimethylsiloxy)-2,6-dimethylphenyl][(2-ethyl-
hex-2-ynyloxy)methoxy]methylene}pentacarbonylchromi-
um(0) (55d)
The carbene complex 55d was prepared from the salt 31 (1.05 g,
1.95 mmol) and chloromethyl ether 56d as a red oil; yield: 1.16 g
(100%); Rf = 0.13 (hexane).
1H NMR (CDCl3): d = 0.18 (s, 6 H), 0.96 (s, 9 H), 1.86 (s, 3 H), 2.10
(s, 6 H), 4.69 (s, 2 H), 5.27–5.30 (4 H), 6.48 (s, 2 H).
13C NMR (CDCl3): d = –4.44, 18.15, 19.54, 23.07, 25.59, 57.63,
81.24, 89.47, 97.03, 119.58, 123.29, 125.72, 128.19, 155.30,
216.25, 224.64, 365.59.
MS m/z (%) = 564 [M+] (0.08), 263 (17), 262 (25), 221 (23), 220
(40), 207 (46), 191 (16), 179 (94), 177 (12), 163 (16), 149 (14), 107
(62), 105 (27), 86 (64), 84 (98), 80 (100), 77 (16), 75 (100), 73 (47),
59 (55), 57 (16), 51 (100), 49 (94), 45 (27).
IR (neat): 2963 m, 2936 m, 2886 w, 2237 vw, 2084 s, 1940 vs, 1601
m, 1471 m, 1315 m, 1253 m, 1155 s, 1064 m, 912 m, 841 s, 655 s
cm–1.
1H NMR (CDCl3): d = 0.18 (s, 6 H), 0.94 (t, J = 7.4 Hz, 3 H), 0.96
(s, 9 H), 1.03 (t, J = 7.5 Hz, 3 H), 1.49 (q, J = 7.5 Hz, 2 H), 1.80 (m,
2 H), 2.10 (s, 6 H), 2.16 (td, J = 6.8, 1.9 Hz, 2 H), 4.67 (t, J = 6.4
Hz, 1 H), 5.20 (br s, 1 H), 5.43 (br s, 1 H), 6.47 (s, 2 H).
13C NMR (CDCl3): d = –4.48, 9.43, 13.36, 18.14, 19.44, 19.54,
20.58, 21.92, 25.58, 29.08, 71.06, 88.59, 97.67, 119.46, 119.62,
127.90, 128.24, 145.00, 155.21, 216.33, 224.63, 364.34.
Pentacarbonyl& lcub;(4-hydroxy-2,6-dimethylphenyl)[(4-
methylpent-4-en-2-ynyloxy)methoxy]methylene}chromium(0)
(54e)
The carbene complex 55e (722 mg, 1.28 mmol) was desilylated ac-
cording to the typical procedure to give phenol carbene complex
54e as a red oil; yield: 287 mg (50%); Rf = 0.21 (hexane–Et2O, 2:1).
MS m/z (%) = 594 [M+] (0.03), 454 [M+ – 5 CO] (19), 425 (18), 424
(47), 423 (37), 422 (91), 420 (25), 385 (15), 373 (15), 372 (24), 371
(22), 358 (20), 357 (33), 356 (39), 343 (16), 330 (20), 329 (53), 327
(25), 315 (23), 271 (17), 263 (63), 257 (33), 243 (17), 191 (23), 165
(16), 163 (18), 128 (19), 125 (18), 115 (19), 75 (36), 74 (24), 73
(100), 72 (64), 59 (18), 57 (36), 56 (28), 55 (24), 52 (47), 51 (25).
IR (neat): 3384 br w, 2959 w, 2928 w, 2228 vw, 2064 sm 1940 vs,
1609 m, 1456 m, 1307 m, 1236 m, 1150 m, 1064 m, 897 m, 653 s
cm–1.
1H NMR (CDCl3): d = 1.86 (s, 3 H), 2.12 (s, 6 H), 4.69 (s, 2 H), 5.05
(br s, 4 H), 6.47 (s, 2 H).
13C NMR (CDCl3) d = 19.53, 23.09, 57.66, 81.19, 89.48, 96.84,
114.97, 123.37, 125.69, 128.75, 144.27, 155.18, 216.23, 224.56,
365.52.
Pentacarbonyl{[(1-ethylhex-2-ynyloxy)methoxy](4-hydroxy-
2,6-dimethylphenyl)methylene}chromium(0) (54d)
MS m/z (%) = 394 [M+ – 2 CO] (0.2), 228 (12), 213 (15), 187 (10),
185 (16), 149 (100), 121 (16), 115 (12), 108 (11), 91 (29), 80 (16),
79 (30), 78 (14), 77 (52), 53 (15), 52 (23), 51 (15).
The carbene complex 55d (951 mg, 1.60 mmol) was desilylated ac-
cording to the typical procedure to give phenol carbene complex
54d as a red oil; yield: 309 mg (40%); Rf = 0.25 (hexane–Et2O, 4:1).
IR (neat): 3400 br w, 2970 w, 2933 w, 2881 w, 2237 vw, 2064 s,
1943 vs, 1149 m, 904 m, 654 m cm–1.
1H NMR (CDCl3): d = 0.93 (t, J = 7.4 Hz, 3 H), 1.03 (t, J = 7.4 Hz,
3 H), 1.49 (q, J = 7.1 Hz, 2 H), 1.80 (m, 2 H), 2.12 (s, 6 H), 2.17 (t,
J = 7.1 Hz, 2 H), 4.67 (br s, 1 H), 5.28 (br s, 1 H), 5.44 (br, 1 H),
6.48 (s, 2 H).
13C NMR (CDCl3): d = 9.43, 13.37, 19.44, 19.55, 20.58, 21.90,
29.07, 71.15, 88.72, 97.54, 114.88, 115.02, 128.46, 128.82, 144.40,
155.12, 216.31, 224.56, 364.30.
MS m/z (%) = 480 [M+] (0.03), 318 (32), 290 (15), 289 (77), 275
(16), 261 (22), 25), 247 (43), 245 (47), 231 (25), 220 (17), 219 (17),
218 (19), 217 (100), 203 (40), 189 (39) 187 (20), 175 (42), 161 (27),
159 (15), 149 (65), 147 (22), 145 (16), 13 (20), 128 (18), 122 (31),
121 (31), 119 (19), 115 (24), 109 (18), 108 (49), 107 939), 105 (30),
97 (24), 95 (15), 94 (18), 93 (26), 91 (58), 81 (37), 80 (76), 79 (69),
78 (19), 77 (69), 69 (23), 67 (54), 65 (25), 57 (35), 55 (46), 53 (38),
52 (98).
{[(5-Benzyloxy-4-methylpent-2-ynyloxy)methoxy](4-hydroxy-
2,6-dimethylphenyl)methylene}pentacarbonylchromium(0)
(54f)
5-Benzyloxy-4-methylpent-2-ynyl Chloromethyl Ether (56f)
The chloromethyl ether 56f was prepared from 4-(benzyloxy)meth-
yl)pent-2-yn-1-ol (334 mg, 1.64 mmol) according to the typical pro-
cedure.
1H NMR (CDCl3): d = 1.19 (d, J = 6.9 Hz, 3 H), 2.77 (m, 1 H), 3.37
(dd, 1 H), 3.49 (dd, 1 H), 4.36 (d, J = 2.2 Hz, 2 H), 4.54 (s, 2 H),
5.56 (s, 2 H), 7.32 (m, 5 H).
{[(5-Benzyloxy-4-methylpent-2-ynyloxy)methoxy][4-(tert-
butyldimethylsiloxy)-2,6-dimethylphenyl]methylene}penta-
carbonylchromium(0) (55f)
The carbene complex 55f was prepared from the salt 31 (700 mg,
1.30 mmol) and chloromethyl ether 56f as red oil; yield: 748 mg
(86%); Rf = 0.45 (hexane–EtOAc, 9:1).
1H NMR (CDCl3): d = 0.18 (s, 6 H), 0.96 (s, 9 H), 1.18 (d, J = 7.1
Hz, 3 H), 2.08 (s, 6 H), 2.77 (m, 1 H), 3.36 (dd, 1 H), 3.47 (dd, 1 H),
Synthesis 2006, No. 21, 3679–3705 © Thieme Stuttgart · New York