PAPER
Bis(propargyloxy) Disulfides
1747
Bis[(1-methylprop-2-ynyl)oxy] Disulfide (9a)
Yellow liquid; strong smell of garlic; mixture of four diastereomers;
yield: 98%.
IR (neat): 1020, 1325, 1374, 2118, 2252, 2990, 3305 cm–1.
1H NMR (300 MHz, CDCl3): d = 4.68, 4.66, 4.65, and 4.63 (qd,
J = 6.6, 2.1 Hz, 2 H each), 2.60, 2.59, 2.554, 2.550 (d, J = 2.1 Hz, 2
H each), 1.56, 1.55, 1.54, and 1.53 (d, J = 6.6 Hz, 6 H each).
Rearrangement of a-Alkyl-Substituted Bis(propargyloxy)
Disulfides; General Procedure
Unless otherwise specified, a CHCl3 soln of the appropriate bis(pro-
pargyloxy) disulfide was stirred at r.t. for 21.5 h.14 This reaction was
characterized by the soln turning dark brown in color. The solvent
was evaporated under reduced pressure and the residue was purified
by chromatography (silica gel).
13C NMR (75 MHz, CDCl3): d = 82.74 and 82.67 (≡C– each), 82.6
(≡C– for two isomers), 75.2, 75.1, 74.8 and 74.7 (≡CH each), 71.1,
71.1, 69.23 and 69.21 (–CH–O each), 22.6, 22.5, 22.4 and 22.3
(–CH3 each).
(3S,5S,6S,Z)- and (3R,5S,6S,Z)-3-Isobutyl-4-(3-methylbutyl-
idene)-6,7-dithiabicyclo[3.1.1]heptan-2-one 6-Oxide (18e and
19e)
A CHCl3 soln of the reactant was heated at reflux for 5 min and the
product was obtained as a mixture of two diastereomers 18e and 19e
(1.8:1.0) as a yellow liquid, upon chromatography (silica gel, n-hex-
ane–EtOAc, 100:1→200:5→95:5→8:1→4:1); total yield: 63%.
MS (CI, CH4): m/z (%) = 203 (23) [MH+], 154 (27) [M+ – ‘SO’],
101 (100) [M+/2].
HRMS: m/z [MH+] calcd for C8H11O2S2: 203.0200; found:
203.0197.
IR (neat): 1114 (S=O), 1714 (C=O) cm–1.
1H NMR (600 MHz, CDCl3): d = 5.97 [td, J = 7.8, 2.3 Hz, 1 H
(=CH–) for 18e] and 5.92 [td, J = 7.8, 1.0 Hz, 1 H (=CH–) for 19e],
5.49 [d, J = 5.1 Hz, 1 H (CH–C=) for 18e] and 5.42 [d, J = 5.0 Hz,
1 H (CH–C=) for 19e], 4.56 ]d, J = 5.1 Hz, 1 H (CH–C=O) for 18e]
and 4.52 [d, J = 5.0 Hz, 1 H (CH–C=O) for 19e], 4.07 [tm, J = 6.0
Hz, 1 H (CH–i-Bu) for 18e] and 3.32 [tm, J = 6.8 Hz, 1 H (CH–i-
Bu) for 19e], 2.12–1.98 (m, 4 H for both diastereomers), 1.88 (sept,
J = 7.8 Hz, 1 H for 19e) and 1.87 (sept, J = 7.8 Hz, 1 H for 18e),
1.703 (sept, J = 7.8 Hz, 1 H for 18e) and 1.698 (sept, J = 7.8 Hz, 1
H for 19e), 0.97 (d, J = 7.8 Hz, 12 H for 18e), 0.93 (d, J = 7.8 Hz, 6
H for 19e), 0.92 (d, J = 7.8 Hz, 6 H for 19e).
13C NMR (150 MHz, CDCl3): d = 201.5 (C=O for 18e) and 200.9
(C=O for 19e), 136.5 (=CH– for 19e) and 134.3 (=CH– for 18e),
128.1 (=C– for 19e) and 127.5 (=C– for 18e), 69.3 (CH–C=O for
18e) and 67.6 (CH–C=O for 19e), 67.4 (CH–C= for 18e) and 65.3
(CH–C= for 19e), 51.0 (–CH–i-Bu for 19e) and 49.5 (–CH–i-Bu for
18e), 37.1 (–CH2– for 18e) and 36.9 (–CH2– for 19e), 34.5 (–CH2–
for both diastereomers), 28.9 [–CH(CH3)2 for 18e] and 28.8
[–CH(CH3)2 for 19e], 26.4 [–CH(CH3)2 for 18e] and 25.8
[–CH(CH3)2 for 19e], 22.9 (–CH3 for 18e), 22.52 [–CH3 (×2) for
18e], 22.51 (–CH3 for 19e), 22.44 (–CH3 for 19e), 22.41 (–CH3 for
19e), 22.4 (–CH3 for 19e), 22.3 (–CH3 for 18e).
Bis(but-2-ynyloxy) Disulfide (10a)
Yellow liquid; strong smell of garlic; yield: 98%.
IR (neat): 928, 1148, 1358, 1439, 1608, 2235, 2918 cm–1.
1H NMR (300 MHz, CDCl3): d (AB system) = 4.47 and 4.40 (dq,
J = 14.7, 2.4 Hz, 2 H), 1.88 (t, J = 2.4 Hz, 6 H).
13C NMR (75 MHz, CDCl3): d = 84.9 (≡C–), 74.2 (≡C–), 62.2
(–CH2–), 3.8 (–CH3).
MS (CI, CH4): m/z (%) = 203 (48) [MH+], 189 (100) [C9H7O2S2],
171 (33) [MH+ – ‘S’], 153 (85).
HRMS: m/z [MH+] calcd for C8H11O2S2: 203.0200; found:
203.0203.
Bis[(1-methyl-3-phenylprop-2-ynyl)oxy] Disulfide (11b)
Yellow liquid; mixture of four diastereomers; yield: 81%.
IR (neat): 1018, 1079, 1330, 1490, 2250, 2986 cm–1.
1H NMR (300 MHz, CDCl3): d = 7.47–7.40 (m, 4 H for four iso-
mers), 7.31–7.27 (m, 6 H for four isomers), 4.93, 4.90, 4.870, and
4.866 (q, J = 6.7 Hz, 2 H each), 1.62 and 1.61 (d, J = 6.7 Hz, 6 H
each), 1.60 (d, J = 6.7 Hz, 6 H for two isomers).
13C NMR (75 MHz, CDCl3): d = 134.9, 131.8, 128.7, 128.6, 128.4,
128.3, and 122.4 (Ar for four isomers), 88.14 and 88.09 (≡C- each),
88.0 (≡C- for two isomers); 86.9 (≡C- for two isomers), 86.7 and
86.6 (≡C- each); 72.0 (-CH- for two isomers), 70.12 and 70.08
(-CH- each), 22.7, 22.62, 22.55, and 22.5 (-CH3 each).
MS (CI, CH4): m/z (%) = 355 (11) [MH+], 323 (19) [MH+ – ‘S’],
307 (13) [MH+ – ‘SO’], 291 (17) [MH+ – ‘SO2’], 275 (14) [MH+ –
‘S2O’], 177 (11) [M+/2], 129 (100).
HRMS: m/z [MH+] calcd for C20H19O2S2: 355.0826; found:
355.0841.
MS (CI, CH4): m/z (%) = 287 (15) [MH+], 253 (17) [(M – H)+ – ‘S’],
237 (21) [(M – H)+ – ‘SO’].
HRMS: m/z [MH+] calcd for C14H23O2S2: 287.1139; found:
287.1135.
Rearrangement of g,g¢-Alkyl-Substituted Bis(propargyloxy)
Disulfides; General Procedure
A CHCl3 soln of the appropriate bis(propargyloxy) disulfide was
heated under reflux for the time indicated in Table 3. This reaction
was characterized by the soln turning a darker color. After the mix-
ture had cooled to r.t., the solvent was evaporated under reduced
pressure and the residue was purified by chromatography (silica gel,
n-hexane–CHCl3, 1:1→1:2→1:3→0:1).
Bis[(1-tert-butylprop-2-ynyl)oxy] Disulfide (12a)
Yellow liquid; mixture of four diastereomers; yield: 83%.
IR (neat): 1129, 1216, 1366, 1477, 1950, 2121, 2966, 3304 cm–1.
(5S,6S)-1,5-Dimethyl-4-methylene-6,7-dithiabicyclo[3.1.1]hep-
tan-2-one 6-Oxide (22a)
1H NMR (300 MHz, CDCl3): d = 4.188, 4.140, 4.138, and 4.132 (d,
J = 2.1 Hz, 2 H each), 2.58, 2.55, 2.51, and 2.50 (d, J = 2.1 Hz, 2 H
each), 1.033 and 1.015 (s, 18 H each), 1.019 (s, 18 H for two iso-
mers).
13C NMR (75 MHz, CDCl3): d = 85.3, 85.0, 81.8, and 81.7 (-CH-
O each), 81.0 and 80.9 (≡C– each), 80.6 (≡C– for two isomers);
76.6, 76.3, 75.7, and 75.6 (≡CH each), 36.3, 36.2, 36.0, and 35.9
[-C(CH3)3 each], 25.8, 25.74, 25.67 and 25.6 [-C(CH3)3 each].
IR (neat): 1098 (S=O), 1715 (C=O) cm–1.
1H NMR (600 MHz, CDCl3): d = 5.40 [t, J = 1.5 Hz, 1 H of =CH2
(cis to -CH2-)], 5.32 [t, J = 2.0 Hz, 1 H of =CH2 (trans to -CH2-)],
AB system: 3.88 (dt, Jgem = 20.5, J = 2.0 Hz, 1 H) and 3.50 (dt,
Jgem = 20.5, J = 1.5 Hz, 1 H), 1.98 [s, 3 H (CH3-CH-C=)], 1.78 [s,
3 H (CH3-CH-C=O)].
13C NMR (75 MHz, CDCl3): d = 198.8 (C=O), 138.6 (=C-), 116.9
(=CH2), 74.50 (-C-C=O), 73.6 (-C-C=), 42.7 (-CH2-), 21.2
(-CH3), 16.8 (-CH3).
MS (CI, CH4): m/z (%) = 286 (42) [M+], 254 (33) [M+ –‘S'], 159
(100).
HRMS: m/z [M+] calcd for C14H22O2S2: 286.1061; found: 286.1059.
Synthesis 2011, No. 11, 1741–1750 © Thieme Stuttgart · New York