The Journal of Organic Chemistry
Article
gel bed (10 cm) and washed with Et2O (100 mL). The filtrate was dried
(MgSO4) and evaporated in vacuo, and the residue was chromato-
graphed on silica gel (hexane/Et2O = 3:1) to give 13 as a pale-yellow
liquid (0.64 g, 67%). 1H NMR (400 MHz, CDCl3): δ 1.18 (s, 9H), 1.31
(s, 9H), 3.35−3.44 (m, 2H), 3.52−3.60 (m, 2H), 6.11 (s, 1H), 9.41 (s,
1H). 13C NMR (100 MHz, CDCl3): δ 27.9, 29.3, 36.5, 40.1, 40.5, 72.0,
82.3, 93.5, 94.7, 101.3, 118.5, 140.8, 175.6. IR (KBr) ν: 2964, 2920,
2867, 2174, 1658, 1460, 1391, 1363, 1185, 1137, 971, 742 cm−1. HRMS
(MALDI, [M + H]+): calcd for C18H25OS2, 321.1347; found, 321.1356.
1-(2-tert-Butyl-1,3-dithiolan-2-yl)-4,8,12-tri-tert-butyl-8-(1,4-
dithiaoctyl)-14-(trimethylsilyl)tetradeca-3Z,11Z-dien-1,5,9,13-
tetrayn-7-ol (23). In a manner similar to that described in the synthesis
of compound 20a, a mixture of 12 (401 mg, 1.10 mmol), nBuLi (0.75 mL,
1.6 M hexane solution, 1.20 mmol), ZnCl2 (170 mg, 1.25 mmol), and
13 (321 mg, 1.00 mmol) was transformed into 23 (23a:23b = 93:7),
which was chromatographed on silica gel (hexane/Et2O = 50:1) to give
23a as pale-yellow liquid (470 mg, 63%). 1H NMR (CDCl3, 400 MHz):
δ 0.20 (s, 9H), 0.90 (t, J = 7.4 Hz, 3H), 1.14 (s, 9H), 1.15 (s, 9H), 1.27 (s,
9H), 1.31 (s, 9H), 1.34−1.42 (m, 2H), 1.48−1.58 (m, 2H), 2.52 (t, J =
7.2 Hz, 2H), 2.68−2.82 (m, 2H), 2.96−3.10 (m, 3H, embodied a
doublet at δ 3.06 (J = 8.4 Hz, 1H)), 3.30−3.40 (m, 2H), 3.50−3.62 (m,
2H), 4.80 (d, J = 8.8 Hz, 1H), 5.78 (s, 1H), 5.79 (s, 1H). 13C NMR
(100 MHz, CDCl3): δ 0.1, 13.9, 22.1, 27.8, 27.9, 29.1, 29.2, 31.8, 31.9,
33.0, 33.2, 36.6, 36.8, 39.6, 40.1, 40.2, 40.3, 64.3, 68.3, 72.4, 83.3, 85.8,
88.2, 91.8, 96.8, 97.4, 103.3, 103.4, 110.1, 112.0, 143.7, 145.2. IR (KBr)
ν: 3480, 2956, 2916, 2849, 2140, 1732, 1456, 1358, 1249, 1199, 906, 876,
841, 730 cm−1. HRMS (MALDI, [M + Na]+): calcd for C42H66NaOS4Si,
765.3665; found, 765.3689. Characteristic 1H NMR signals for 23b (400
MHz, CDCl3): δ 4.98 (d, J = 10.4 Hz, 1H, RR′HCOH).
1-Trimethylsilyl-3,7,11-tri-tert-butyl-14-(2-tert-butyl-1,3-dithiolan-
2-yl)tetradeca-3Z,7Z,11Z- trien-1,5,9,13-tetrayne (15). In a manner
similar to that described in the synthesis of compound 12, a mixture
of 23a (744 mg, 1.0 mmol), DIAD (0.43 mL, 2.2 mmol), and PPh3
(524 mg, 2.0 mmol) was transformed into the crude product, which was
recrystallized in Et2O/MeOH to obtain 15 as a white solid (410 mg,
71%). Mp: 109−110 °C. 1H NMR (400 MHz, CDCl3): δ 0.20 (s, 9H),
1.15 (s, 9H), 1.19 (s, 9H), 1.23 (s, 9H), 1.32 (s, 9H), 3.30−3.40 (m,
2H), 3.50−3.60 (m, 2H), 5.78 (s, 1H), 5.87 (s, 1H), 5.89 (s, 1H). 13C
NMR (100 MHz, CDCl3): δ 0.1, 27.8, 29.1, 29.2, 29.5, 36.5, 36.6, 36.8,
40.1, 40.2, 72.4, 83.9, 93.8, 93.9, 96.4, 96.5, 97.7, 103.2, 103.4, 111.2,
111.8, 112.3, 144.5, 144.9, 145.3. IR (KBr) ν: 2963, 2934, 2898 2875,
2134, 1457, 1366, 1249, 1199, 1100, 878, 841 cm−1. HRMS (MALDI,
[M + H]+): calcd for C36H53S2Si, 577.3358; found, 577.3358.
4,8,12-Tri-tert-butyl-15-(2-tert-butyl-1,3-dithiolan-2-yl)-
pentadeca-4Z,8Z,12Z-trien-2,6,10,14- tetrayn-1-al (24). By the
same procedure as described in the synthesis of compound 13, a mixture
of 15 (400 mg, 0.69 mmol) and K2CO3 (400 mg, 2.90 mmol) was
transformed into the terminal alkyne as a white solid (315 mg, 90%). A
mixture of the terminal alkyne (300 mg, 0.52 mmol), MeMgI (1.0 mL,
1.0 M Et2O solution, 1.0 mmol), and paraformaldehyde (72 mg,
2.4 mmol) was then transformed into the corresponding alcohol as a
white solid (198 mg, 71%). A mixture of the alcohol (175 mg,
0.33 mmol) and MnO2 (600 mg, 6.9 mmol) was transformed into 24 as
a pale-yellow oil (120 mg, 69%). 1H NMR (400 MHz, CDCl3): δ 1.18 (s,
9H), 1.19 (s, 9H), 1.23 (s, 9H), 1.31 (s, 9H), 3.32−3.41 (m, 2H), 3.50−
3.58 (m, 2H), 5.80 (s, 1H), 5.94 (s, 1H), 6.19 (s, 1H), 9.39 (s, 1H).
13C NMR (100 MHz, CDCl3): δ 27.7, 29.1, 29.2, 29.3, 36.5, 36.6,
36.7, 40.1, 40.2, 72.4, 83.7, 93.3, 94.6, 95.1, 95.2, 95.9, 97.0, 98.0, 111.8,
113.2, 118.6, 141.5, 144.4, 144.5, 176.1. IR (KBr) ν: 2965, 2929, 2868,
2176, 1660, 1477, 1460, 1391, 1362, 1252, 1195, 1136, 968, 837, 745,
650 cm−1. HRMS (ESI, [M + Na]+): calcd for C34H44ONaS2, 555.2731;
found, 555.2750.
1-Trimethylsilyl-3,7,11,15-tetra-tert-butyl-18-(2-tert-butyl-
1,3-dithiolan-2-yl)octadeca-3Z,7Z,11Z,15Z-tetraen-1,5,9,13,17-
pentayne (16). In a manner similar to that described in the synthesis of
20, a mixture of 15 (120 mg, 0.21 mmol), nBuLi (0.15 mL, 1.6 M hexane
solution, 0.24 mmol), ZnCl2 (34 mg, 0.25 mmol), and 11 (54 mg,
0.25 mmol) was transformed into the homopropargylic alcohol as an
orange-yellow oil (122 mg, 68%). In a manner similar to that described
in the synthesis of 12, a mixture of the homopropargylic alcohol, DIAD
(0.22 mL, 1.1 mmol), and PPh3 (262 mg, 1.0 mmol) was transformed
into the crude product, and subsequent chromatographic separation on
silica gel (hexane/Et2O = 50:1) and recrystallization in Et2O/MeOH
afforded 16 as pale-yellow solid (52 mg, 36% for two steps). Mp: 135−
136 °C. 1H NMR (400 MHz, CDCl3): δ 0.20 (s, 9H), 1.16 (s, 9H), 1.20
(s, 9H), 1.22 (s, 9H), 1.23 (s, 9H), 1.32 (s, 9H), 3.32−3.42 (m, 2H),
3.50−3.60 (m, 2H), 5.77 (s, 1H), 5.86 (s, 1H), 5.88 (s, 1H), 5.89 (s,
1H). 13C NMR (100 MHz, CDCl3): δ −0.1, 27.7, 29.0, 29.1, 29.2, 29.4,
36.5, 36.6, 36.7, 40.0, 40.1, 72.5, 84.0, 93.9, 96.5, 96.7, 97.3, 97.7, 103.3,
103.5, 111.3, 111.5, 111.9, 112.3, 144.7, 145.1, 145.5, 145.7. IR (KBr) ν:
2962, 2930, 2873, 2136, 1480, 1457, 1395, 1361, 1250, 1198, 1152,
1101, 1032, 878, 841 cm−1. HRMS (MALDI, [M + H]+): calcd for
C44H63S2Si, 683.4141; found, 683.4161.
1-Trimethylsilyl-3,7,11,15,19-penta-tert-butyl-22-(2-tert-
butyl-1,3-dithiolan-2-yl)docosa-3Z,7Z,11Z,15Z,19Z-pentaen-
1,5,9,13,17,21-hexayne (17). In a manner similar to that described
n
in the synthesis of 20, a mixture of 15 (120 mg, 0.21 mmol), BuLi
(0.15 mL, 1.6 M hexane solution, 0.24 mmol), ZnCl2 (34 mg, 0.25 mmol),
and 13 (80 mg, 0.25 mmol) was transformed into the homopropargylic
alcohol as an orange-yellow oil (127 mg, 63%). In a manner similar
to that described in the synthesis of compound 12, a mixture of the
homopropargylic alcohol, DIAD (0.22 mL, 1.1 mmol), and PPh3
(262 mg, 1.0 mmol) was transformed into the crude product, and
subsequent chromatographic separation on silica gel (hexane/Et2O =
50:1) and recrystallization in Et2O/MeOH afforded 17 as a yellow solid
(55 mg, 33% for two steps). Mp: 180 °C (dec.). 1H NMR (400 MHz,
CDCl3): δ 0.20 (s, 9H), 1.16 (s, 9H), 1.20 (s, 9H), 1.22 (s, 9H), 1.23
(br s, 18H), 1.25 (s, 9H), 1.32 (s, 9H), 3.32−3.42 (m, 2H), 3.50−3.60
(m, 2H), 5.77 (s, 1H), 5.85 (s, 1H), 5.86 (s, 1H), 5.87 (s, 1H), 5.89 (s,
1H). 13C NMR (100 MHz, CDCl3): δ 0.1, 27.8, 29.0, 29.1, 29.2, 29.3,
29.5, 36.6, 36.7, 36.8, 40.1, 40.2, 72.5, 83.9, 93.9, 96.5, 96.6, 97.2, 97.3,
97.6, 103.2, 103.5, 111.1 111.4 111.5 111.7, 112.2, 144.8, 145.1, 145.6,
145.8. IR (KBr) ν: 2963, 2972, 2904, 2865, 2140, 1483, 1456, 1395,
1364, 1256, 1202, 1152, 1105, 881, 840 cm−1. HRMS (MALDI,
[M + H]+): calcd for C52H73S2Si, 789.4923; found, 789.4952.
1-Trimethylsilyl-3,7,11,15,19,23,27-hepta-tert-butyl-30-(2-tert-
butyl-1,3-dithiolan-2-yl)triaconta-3Z,7Z,11Z,15Z,19Z,23Z,27Z-
heptaen-1,5,9,13,17,21,25,29-octayne (18). In a manner similar
to that described in the synthesis of 20, a mixture of 15 (120 mg,
0.21 mmol), nBuLi (0.15 mL, 1.6 M hexane solution, 0.24 mmol), ZnCl2
(34 mg, 0.25 mmol), and 24 (133 mg, 0.25 mmol) was transformed into
the homopropargylic alcohol as an orange-yellow solid (149 mg, 61%).
In a manner similar to that described in the synthesis of compound 12, a
mixture of the homopropargylic alcohol, DIAD (0.22 mL, 1.1 mmol),
and PPh3 (262 mg, 1.0 mmol) was transformed into the crude product,
and subsequent chromatographic separation on silica gel (hexane/
Et2O = 50:1) and recrystallization in Et2O/MeOH afforded 18 as a
yellow solid (64 mg, 30% for two steps). Mp: 180 °C (dec.). 1H NMR
(400 MHz, CDCl3): δ 0.21 (s, 9H), 1.16 (s, 9H), 1.20 (s, 9H), 1.22 (s,
9H), 1.23 (s, 9H), 1.24 (br s, 27H), 1.33 (s, 9H), 3.32−3.42 (m, 2H),
3.52−3.60 (m, 2H), 5.77 (s, 1H), 5.85 (s, 1H), 5.86 (br s, 3H), 5.87 (s,
1H), 5.89 (s, 1H). 13C NMR (100 MHz, CDCl3): δ −0.1, 27.7, 29.1,
29.2, 29.4, 36.5, 36.6, 36.7, 40.0, 40.1, 72.5, 84.0, 93.9, 94.0, 94.1, 96.5,
96.7, 97.4, 97.5, 97.7, 103.3, 103.5, 111.2, 111.4, 111.5, 111.8, 112.3,
144.8, 145.1, 145.6, 145.8, 145.9, 150.0. IR (KBr) ν: 2966, 2954, 2931,
2904, 2873, 2140, 1478, 1460, 1399, 1360, 1253, 1152, 1098, 1024, 878,
841 cm−1. HRMS (MALDI, [M + H]+): calcd for C68H93S2Si, 1001.6488;
found, 1001.6527.
1-Trimethylsilyl-3,7,11,15,19,23,27,31,35-nona-tert-butyl-
38-(2-tert-butyl-1,3-dithiolan-2-yl)octatriaconta-
3 Z , 7 Z , 1 1 Z , 1 5 Z , 1 9 Z , 2 3 Z , 2 7 Z , 3 1 Z , 3 5 Z - n o n a e n -
1,5,9,13,17,21,25,29,33,37-decayne (19). In a manner similar
to that described in the synthesis of compound 20, a mixture of 17
(100 mg, 0.13 mmol), nBuLi (0.10 mL, 1.6 M hexane solution,
0.16 mmol), ZnCl2 (30 mg, 0.22 mmol), and 24 (100 mg, 0.19 mmol)
was transformed into the homopropargylic alcohol as an orange-yellow
solid (105 mg, 59%). In a manner similar to that described in the
synthesis of compound 12, a mixture of the homopropargylic alcohol,
DIAD (0.22 mL, 1.1 mmol), and PPh3 (262 mg, 1.0 mmol) was trans-
formed into the crude product, and subsequent chromatographic
H
J. Org. Chem. XXXX, XXX, XXX−XXX