Functionalized nanodiamonds part 3: Thiolation of tertiary/bridgehead alcohols

Article abstract of DOI:10.1021/ol053136g

Treatment of acyclic as well as polycyclic tertiary mono- and dihydroxy hydrocarbon derivatives with thiourea in the presence of hydrobromic and acetic acid represents a convenient one-step route to the respective tertiary thiols and dithiols. This procedure was used for the preparation of diamondoid thiols of diamantane, triamantane, [121]tetramantane, and others that are prospective nanoelectronic materials.

Full text of DOI:10.1021/ol053136g

ORGANIC
LETTERS
2006
Vol. 8, No. 9
1767-1770
Functionalized Nanodiamonds Part 3:
Thiolation of Tertiary/Bridgehead
Alcohols
|
Boryslav A. Tkachenko, Natalie A. Fokina, Lesya V. Chernish,‡
Jeremy E. P. Dahl,§ Shenggao Liu,§ Robert M. K. Carlson,§
,‡
Andrey A. Fokin,*,
and Peter R. Schreiner*,
Institut fu¨r Organische Chemie, Justus-Liebig UniVersity, Heinrich-Buff-Ring 58,
D-35392 Giessen, Germany, Department of Organic Chemistry, KieV Polytechnic
Institute, pr. Pobedy 37, 03056 KieV, Ukraine, and MolecularDiamond Technologies,
CheVron Technology Ventures LLC, 100 CheVron Way, Richmond, California 94802
aaf@xtf.ntu-kpi.kieV.ua; prs@org.chemie.uni-giessen.de
Received December 27, 2005
ABSTRACT
Treatment of acyclic as well as polycyclic tertiary mono- and dihydroxy hydrocarbon derivatives with thiourea in the presence of hydrobromic
and acetic acid represents a convenient one-step route to the respective tertiary thiols and dithiols. This procedure was used for the preparation
of diamondoid thiols of diamantane, triamantane, [121]tetramantane, and others that are prospective nanoelectronic materials.
Incorporation of thiol groups into organic molecules allows
their attachment to nobel metal surfaces to form self-
assembled monolayers (SAMs)1 that have applications in
molecular electronics.2,3 Nanodiamonds functionalized with
SH groups offer fascinating new possibilities for “diamond
on gold” surface design in monolayer formation. The smallest
nanodiamonds (also referred to as diamondoids, Figure 1),
whose 1-2 nm sized carbon frameworks resemble a part of
the diamond lattice, may allow more rational surface design
than traditional conformationally flexible substrates.4 Unlike
Figure 1. Structures of diamantane (1), triamantane (2), and [121]-
tetramantane (3).
| For parts 1 and 2, see refs 13 and 14.
Justus-Liebig University.
‡ Kiev Polytechnic Institute.
§ Chevron Technology Ventures.
aryl3,5 and alkyl1 thiols that are widely utilized for the
(1) Ulman, A. Chem. ReV. 1996, 96, 1533-1554.
(2) Tour, J. M. Acc. Chem. Res. 2000, 33, 791-804.
(3) de Boer, B.; Meng, H.; Perepichka, D. F.; Zheng, J.; Frank, M. M.;
Chabal, Y. J.; Bao, Z. N. Langmuir 2003, 19, 4272-4284.
(4) Dameron, A. A.; Charles, L. F.; Weiss, P. S. J. Am. Chem. Soc. 2005,
127, 8697-8704.
preparation of SAMs, rigid diamondoids are likely to display
(5) Maya, F.; Flatt, A. K.; Stewart, M. P.; Shen, D. E.; Tour, J. M. Chem.
Mater. 2004, 16, 2987-2997.
10.1021/ol053136g CCC: $33.50
© 2006 American Chemical Society
Published on Web 03/28/2006

unique SAM properties. The simplest thiolated diamondoid,
adamantane-1-thiol, forms SAMs with fewer defects and
looser bonding to the Au{111} surface than n-alkane-
thiolates.4 Furthermore, one can achieve diversity of SAMs
varying not only the three-dimensional shape of the hydro-
carbon but also the position of the -SH group in the cage.
This allows the preparation of coated surfaces with novel
properties by varying intermolecular distance, surface struc-
ture, thickness, etc. Diamondoid dithiols are also promising
building blocks for molecular conductance junctions6 in
nanoelectronic devices7 and, because of the parallel hyper-
conjugated σC-C bonds, may show better conductivity than
conformationally flexible n-alkane dithiols.8
Although several lower diamondoids can be prepared
synthetically through elaborate multistep procedures,9 the
newly discovered natural source10 (crude oil) makes dia-
mantane (1), triamantane (2), and [121]tetramantane11 (3)
available in considerable quantities (Figure 1). Selective
functionalizations of diamondoids are known12 to be rather
difficult because of the large number of tertiary C-H bonds
with similar reactivity; some general approaches to solve this
problem are outlined in our previous work.13,14 Diamondoid
alcohols have been chosen as starting materials for the
preparation of thiols because they are readily available
through the oxidations of diamondoids. Alcohols 17-19 and
23-25 (Figure 2) were prepared via oxidation with HNO313,15
and 20-22, 26, and 27 through a three-step procedure that
includes irradiation with diacetyl, Baeyer-Villiger oxidation
of the respective acetyl derivatives to the acetates, and their
base-promoted hydrolysis.14
Figure 2. Selected thiols and dithiols prepared from the respective
hydroxy derivatives (yields of thiols are preparative).
Although the most obvious method for the incorporation
of an SH group is the substitution of halogen or hydroxyl
functions, these transformations turned out to be a difficult
task for diamondoids. Despite a number of thiolation reagents
widely used for primary and secondary substrates (mostly
bromides), model reactions with 1-bromoadamantane (for
example, involving hydrogen sulfide,16 organolithium re-
agents with elemental sulfur,17 potassium thioacetate18 and
ethyl xanthogenate,19 sodium dimethyldithiocarbamate,20
hydrosulfide,21 and thiosulfate22) resulted in no conversion
or proceeded in unsatisfactory yields of the respective
adamantane-1-thiol; only the reaction with thiourea23 gave
a satisfactory yield. This is likely to be a consequence of
the steric shielding of the tertiary bridgehead position that
prevents the backside attack of the reagent.
Condensation of the bromides in ethanol with thiourea
followed by hydrolysis of the thiouronium salt intermediate
under basic conditions is considered to be a good thiolation
method for various bromides and is widely utilized for the
preparation of primary and secondary thiols. For 1-bromo-
adamantane, we found that ethanol (used as the solvent)
reacts with the intermediate cation to give 1-ethoxyadaman-
tane in quantities comparable to those for the desired product.
Replacing the solvent with polar aprotic DMSO, which is
known to facilitate this reaction considerably for primary
and secondary derivatives,24 gave no conversion. We deve-
loped a procedure that utilizes the diamondoid alcohols
(6) (a) Nitzan, A.; Ratner, M. A. Science 2003, 300, 1384-1389. (b)
Xue, Y. Q.; Ratner, M. A. Int. J. Quantum Chem. 2005, 102, 911-924.
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E.; Bao, Z. Langmuir 2004, 20, 1539-1542.
(8) Sun, Q.; Selloni, A.; Scoles, G. ChemPhysChem 2005, 6, 1906-
1910.
(9) (a) Burns, W.; Mitchell, T. R. B.; McKervey, M. A.; Rooney, J. J.;
Ferguson, G.; Roberts, P. J. Chem. Soc., Chem. Commun. 1976, 893-895.
(b) McKervey, M. A. Tetrahedron 1980, 36, 971-992.
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(11) Balaban, A. T.; Schleyer, P. v. R. Tetrahedron 1978, 34, 3599-
3609.
(12) Hollowood, F.; Karim, A.; McKervey, M. A.; McSweeney, P. J.
Chem. Soc., Chem. Commun. 1978, 306-308.
(13) Fokin, A. A.; Tkachenko, B. A.; Gunchenko, P. A.; Gusev, D. V.;
Schreiner, P. R. Chem.-Eur. J. 2005, 11, 7091-7101.
(14) Schreiner, P. R.; Fokina, N. A.; Tkachenko, B. A.; Hausmann, H.;
Serafin, M.; Dahl, J. E. P.; Liu, S. G.; Carlson, R. M. K.; Fokin, A. A. J.
Org. Chem. 2006, 71, in press. DOI: 10.1021/jo0526461.
(15) Moiseev, I. K.; Belyaev, P. G.; Barabanov, N. V.; Bardyug, O. P.;
Vishnevskii, E. N.; Novatskaya, N. I.; Golod, E. L.; Gidaspov, B. V. Zh.
Org. Khim. 1975, 11, 214-215.
(18) Chapman, J. H.; Owen, L. N. J. Chem. Soc. 1950, 579-585.
(19) Djerassi, C.; Gorman, M.; Markley, F. X.; Oldenburg, E. B. J. Am.
Chem. Soc. 1955, 77, 568-571.
(20) Kulka, M. Can. J. Chem. 1956, 34, 1093-1100.
(21) Ellis, L. M.; Reid, E. E. J. Am. Chem. Soc. 1932, 54, 1674-1687.
(22) El-Hewehi, Z.; Taeger, E. J. Prakt. Chem. 1958, 7, 191-195.
(23) (a) Khullar, K. K.; Bauer, L. J. Org. Chem. 1971, 36, 3038-3040.
(b) Kokosa, J. M.; Bauer, L.; Egan, R. S. J. Org. Chem. 1975, 40, 3196-
3199. (c) Cahill, P. A. Tetrahedron Lett. 1990, 31, 5417-5420.
(24) Pan, H. L.; Fletcher, T. L. Chem. Ind. 1968, 546.
(16) Balfe, M. P.; Kenyon, J.; Searle, C. E. J. Chem. Soc. 1950, 3309-
3312.
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6, 979-980.
1768
Org. Lett., Vol. 8, No. 9, 2006

Scheme 1. Generalized Mechanistic Proposal for the Preparation of Thiols from Tertiary Alcohols
instead of the bromides (comparative reactions of bromides
Similar to the fused polyadamantane diamondoids, oligo-
1,3-adamantanes also can be recognized as repeating units
of the diamond lattice28 with 1,1’-diadamantyl (28) being
produced thiols in poor yields). Previous attempts to obtain
adamantane-1-thiol from 1-hydroxyadamantane25 with
Lawesson’s reagent {2,4-bis(4-methoxyphenyl)-1,3,2,4-
dithiadiphosphetane-2,4-disulfide} gave only 30% of the
desired product. The reaction with thiourea in a CH3COOH/
HBraq mixture resulted in the direct conversion of various
tertiary alcohols to the respective thiols (as generalized in
Scheme 1). Workup requires some attention as disulfides
(formed by air oxidation of the aqueous thiolates; Scheme
1), as well as thiocyanates (products of the thermal decom-
position of the intermediate thiouronium salts), form. This
makes the isolation of pure thiols somewhat tedious; this is
especially critical for increasingly larger diamondoid thiols.
The use of such polar solvents implies that tertiary
bridgehead carbocations form as intermediates in the course
of the reaction. In our previous work,13 we found that the
diamondoid apical cations are less stable than the medial
ones. For instance, the diamantyl-1-cation is 3.1 kcal mol-1
more stable than the diamantyl-4-cation, and one would
expect the formation of mixtures of isomeric thiols, as
previously found for the equilibration of 1- and 4-diaman-
tanols in acidic media.26 However, we did not find any
isomerization products en route from the alcohols to the
respective thiols (Scheme 1; see Supporting Information for
details). For instance, the reaction of 4-hydroxy diamantane
(20) produces 4-derivatives exclusively. Hence, nucleophilic
trapping of the diamandoidyl cation by thiourea is faster than
bimolecular exchange reactions that would give the thermo-
dynamically most stable cation.
To probe the applicability of our method to simpler cage
and acyclic alcohols, the reaction was also performed with
3-ethylpentane-3-ol (16), bicyclo[3.3.1]nonane-1-ol (18), and
protoadamantane-6-ol (19), which all gave good yields of
the respective thiols (4-7).27 The very low yield of the thiol
from bicyclo[2.2.2]octane-1-ol (17) can readily be explained
by the instability of the respective carbocation intermediate.
Thiolation of diamondoid alcohols requires longer reaction
times (3 h) than for 16, 18, and 19; the apical derivatives
(20-22) are generally more reactive than the medial (23-
25) ones (reactions complete in approximately 10 h).
Incorporation of two SH groups (thiols 14 and 15) requires
longer reaction times.
(27) Characterization of thiols. 3-Ethylpentane-3-thiol (4), yield 88%,
colorless liquid. 1H NMR: 1.58 (q, 6H, J ) 7.4 Hz), 1.30 (s, 1H), 0.91 (t,
9H, J ) 7.4 Hz). 13C NMR: 52.7 (C), 32.8 (CH2), 8.5 (CH3). MS (m/z):
132 (16%), 103 (16%), 99 (18%), 69 (28%), 61 (30%), 57 (100%), 55
(10%). HR-MS (m/z): found, 132.0981; calcd for C7H16S, 132.0973.
Bicyclo[2.2.2]octane-1-thiol (5) was not isolated. After workup, yellow
oil was isolated that cointained ∼4% of the product. MS (m/z): 142 (87%),
115 (43%), 109 (100%), 86 (90%), 79 (42%), 67 (78%), 55 (18%). Bicyclo-
[3.3.1]nonane-1-thiol (6), yield 58%, white solid, mp ) 32-35 °C. 1H
NMR: 2.15-1.45 (m, 16H). 13C NMR: 45.8 (CH2), 44.8 (C), 41.6 (CH2),
30.8 (CH), 29.8 (CH2), 23.7 (CH2). MS (m/z): 156 (20%), 123 (100%),
113 (10%), 81 (88%), 67 (45%), 55 (17%). HR-MS (m/z): found, 156.0968;
calcd for C9H16S, 156.0973. Protoadamantane-6-thiol (7), yield 57%, white
1
solid, mp ) 36-40 °C. H NMR: 2.35-1.25 (m, 16H). 13C NMR: 50.7
(CH2), 44.2 (C), 44.0 (CH2), 41.0 (CH2), 37.4 (CH2), 36.3 (CH2), 36.2 (CH),
36.0 (CH), 32.7 (CH), 24.7 (CH2). MS (m/z): 168 (12%), 135 (100%),
107 (9%), 93 (23%), 79 (31%), 67 (18%), 55 (7%). HR-MS (m/z): found,
168.0970; calcd for C10H16S, 168.0973. Diamantane-4-thiol (8), yield 76%,
white solid, mp ) 63-64 °C. 1H NMR: 1.89 (m, 6H), 1.84 (bs, 3H), 1.78
(bs, 1H), 1.75-1.68 (m, 9H), 1.62 (s, 1H). 13C NMR: 48.2 (CH2), 41.6
(C), 39.3 (CH), 37.3 (CH2), 35.9 (CH), 25.4 (CH). MS (m/z): 220 (7%),
187 (100%), 159 (1%), 145 (4%), 131 (6%), 117 (2%), 105 (6%), 91 (8%),
79 (7%), 77 (4%). HR-MS (m/z): found, 220.1264; calcd for C14H20S,
220.1286. Triamantane-9-thiol (9), yield 81%, white solid, mp ) 77-79
°C. 1H NMR: 1.97-1.81 (m, 5H), 1.78 (bs, 2H), 1.75-1.58 (m, 11H),
1.47 (s, 2H), 1.42 (bs, 2H), 1.29 (m, 2H). 13C NMR: 55.0 (CH2), 47.9
(CH2), 45.2 (CH), 44.7 (CH2), 42.7 (C), 39.9 (CH), 37.8 (CH2), 37.6 (CH2),
37.4 (CH), 35.4 (C), 34.8 (CH), 33.6 (CH), 27.3 (CH). MS (m/z): 272
(3%), 256 (5%), 239 (100%), 197 (1%), 183 (2%), 157 (4%), 143 (10%),
129 (10%), 128 (6%), 119 (8%), 105 (11%), 91 (24%), 79 (11%), 77 (10%),
67 (7%). HR-MS (m/z): found, 272.1594; calcd for C18H24S, 272.1599.
[121]Tetramantane-6-thiol (10), yield 82%, white solid, mp ) 109-112
1
°C. H NMR: 1.88 (bs, 4H), 1.78 (bs, 2H), 1.72-1.63 (m, 8H), 1.57 (s,
2H), 1.52 (s, 2H), 1.43 (bs, 2H), 1.35 (bs, 2H), 1.30 (d, J ) 2.9 Hz, 2H),
1.26 (m, 4H). 13C NMR: 54.1 (CH2), 47.8 (CH2), 46.7 (CH), 45.7 (CH),
45.2 (CH2), 44.9 (CH2), 44.1 (CH2), 42.9 (C), 39.9 (CH), 38.0 (CH), 37.8
(CH2), 36.6 (CH), 35.3 (CH), 33.4 (C), 31.1 (C), 27.8 (CH). MS (m/z):
324 (3%), 308 (10%), 291 (100%), 169 (3%), 155 (11%), 145 (20%), 141
(8%), 129 (7%), 105 (6%), 91 (10%). HR-MS (m/z): found, 324.1897;
calcd for C22H28S, 324.1912. Diamantane-1-thiol (11), yield 82%, white
1
solid, mp ) 227-229 °C. H NMR: 2.31 (d, J ) 12.8 Hz, 2H), 1.97 (m,
2H), 1.90 (bs, 3H), 1.83-1.64 (m, 10H), 1.58 (s, 1H), 1.52 (d, J ) 12.8
Hz, 2H). 13C NMR: 51.2 (C), 50.7 (CH2), 44.4 (CH), 39.3 (CH), 38.4 (CH2),
37.7 (CH2), 36.5 (CH), 34.0 (CH2), 29.4 (CH), 25.5 (CH). MS (m/z): 220
(5%), 187 (100%), 159 (2%), 145 (3%), 131 (6%), 117 (4%), 105 (9%), 91
(14%), 79 (7%), 77 (6%). HR-MS (m/z): found, 220.1272; calcd for
C14H20S, 220.1286. Triamantane-3-thiol (12), yield 72%, white solid, mp
1
) 145-146 °C. H NMR: 2.32-2.23 (m, 2H), 2.06-1.97 (m, 2H), 1.95
(m, 1H), 1.88-1.59 (m, 11H), 1.55 (s, 1H), 1.53-1.39 (m, 3H), 1.37-
1.22 (m, 4H). 13C NMR: 53.4 (CH), 51.9 (C), 50.7 (CH2), 45.8 (CH), 45.0
(CH2), 44.9 (CH2), 42.3 (CH), 39.6 (CH), 37.8 (CH2), 37.7 (CH), 37.6 (CH2),
37.6 (CH2), 35.7 (C), 35.0 (CH), 34.6 (CH2), 33.6 (CH), 30.3 (CH), 27.7
(CH). MS (m/z): 272 (2%), 239 (100%), 167 (9%), 143 (17%), 129 (20%),
128 (9%), 105 (10%), 91 (23%), 67 (6%). HR-MS (m/z): found, 272.1600;
calcd for C18H24S, 272.1599. [121]Tetramantane-2-thiol (13), yield 85%,
white solid, mp ) 102-105 °C. 1H NMR: 2.53-2.45 (m, 2H), 1.98-1.82
(m, 5H), 1.80-1.60 (m, 10H), 1.58 (m, 1H), 1.56-1.52 (m, 2H), 1.47 (bs,
1H), 1.41 (bs, 1H), 1.39-1.23 (m, 4H), 1.10-1.03 (m, 1H), 1.00-0.94
(m, 1H). 13C NMR: 60.6 (C), 55.3 (CH), 49.4 (CH), 47.5 (CH), 46.7 (CH),
45.5 (CH2), 44.3 (CH2), 41.3 (CH2), 39.7 (CH2), 39.3 (CH), 38.7 (CH2),
(25) Nishio, T. J. Chem. Soc., Perkin Trans. 1 1993, 1113-1117.
(26) Courtney, T.; Johnston, D. E.; Rooney, J. J.; McKervey, M. A. J.
Chem. Soc., Perkin Trans. 1 1972, 2691-2696.
Org. Lett., Vol. 8, No. 9, 2006
1769

We have developed a straightforward one-pot method for
the synthesis of tertiary thiols from their corresponding
alcohols. The thiolation procedure can be applied to a large
range of tertiary alcohols that are able to form tertiary cations.
The position and number of hydroxy groups in the diamon-
doid cages have a considerable influence on the reaction time.
To the best of our knowledge, the method described here is
the only path to nanodiamond thiols as well as to many
related tertiary cage hydrocarbon thiols.
Figure 3. 1,1′-Diadamantyl 28, its alcohols (29, 30), and corre-
sponding thiols (31, 32) (yields of thiols are preparative).
General Procedure for the Preparation of Thiols. To a
stirred solution of thiourea (11.40 g, 150 mmol) in glacial
acetic acid (50 mL) and 48% aqueous HBr (25 mL) was
added the respective hydroxy diamondoid (1 mmol). The
mixture was homogenized within about 30 min and was
refluxed under argon for 3 h (in the case of alcohols 16, 18,
19, 29), 6 h (alcohols 20-22, 30), 10 h (alcohols 23-25),
and 48 h (alcohols 17, 26, 27). The hot reaction mixture
was poured in small portions into a cold (ice bath) 15%
aqueous NaOH solution (600 mL) and was stirred overnight
at room temperature. The resulting sodium thiolate suspen-
sion/solution was cooled (ice bath) and was acidified with
50% aqueous H2SO4 to pH ) 2-3 while maintaining the
temperature below 10 °C. The crude product was extracted
with chloroform (5 × 15 mL), and the combined extracts
were washed with aqueous NaHCO3 solution (10 mL) and
brine and dried over Na2SO4. Solvent removal gave the crude
thiol which was purified via column chromatography on
silica gel (CCl4).
the smallest representative hydrocarbon (Figure 3). Our
thiolation protocol works well for both the mono- (29)29 and
the dihydroxy (30)30 derivatives, and the corresponding
monothiol (31) and dithiol (32) products were obtained in
good yields.
38.5 (CH), 38.0 (CH), 37.8 (CH2), 37.5 (CH2), 36.9 (CH), 35.2 (C), 34.6
(C), 34.2 (CH2), 33.5 (CH), 27.8 (CH), 27.4 (CH). MS (m/z): 324 (1%),
291 (100%), 162 (5%), 155 (14%), 145 (8%), 141 (16%), 105 (5%), 91
(8%). HR-MS (m/z): found, 324.1905; calcd for C22H28S, 324.1912.
Diamantane-4,9-dithiol (14), yield 69%, white solid, mp ) 211.5-214.5
°C. 1H NMR: 1.91 (bs, 12H), 1.82 (bs, 6H), 1.65 (s, 2H). 13C NMR: 47.1
(CH2), 41.0 (C), 37.5 (CH). MS (m/z): 252 (21%), 219 (100%), 203 (3%),
185 (11%), 157 (2%), 143 (7%), 129 (7%), 105 (6%), 91 (10%). HR-MS
(m/z): found, 252.1014; calcd for C14H20S2, 252.1006. [121]Tetramantane-
6,13-dithiol (15), yield 29%, white solid, mp ) 193-195 °C. 1H NMR:
1.94-1.84 (m, 8H), 1.79 (bs, 4H), 1.69 (m, 2H), 1.65 (s, 2H), 1.52 (bs,
4H), 1.40 (bs, 4H), 1.30 (s, 2H), 1.29 (s, 2H). 13C NMR: 53.9 (CH2), 47.7
(CH2), 45.1 (CH), 44.3 (CH2), 42.6 (C), 39.8 (CH), 34.9 (CH), 33.1 (C).
MS (m/z): 356 (4%), 323 (100%), 155 (3%), 145 (14%), 91 (8%). HR-MS
(m/z): found, 356.1632; calcd for C22H28S2, 356.1632. 1,1’-Diadamantane-
3-thiol (31), yield 78%, white solid, mp ) 144-145.5 °C. 1H NMR: 2.15-
2.03 (m, 2H), 2.02-1.88 (m, 4H), 1.87-1.77 (m, 3H), 1.74 (bs, 3H), 1.68
(s, 1H), 1.67-1.59 (m, 5H), 1.59-1.53 (m, 8H), 1.53-1.47 (m, 4H). 13C
NMR: 47.3 (CH2), 45.8 (CH2), 44.6 (C), 39.4 (C), 37.4 (CH2), 36.4 (C),
35.6 (CH2), 35.3 (CH2), 33.6 (CH2), 30.5 (CH), 28.9 (CH). MS (m/z): 302
(2%), 269 (68%), 135 (100%), 93 (15%), 79 (15%), 67 (6%), 55 (4%).
HR-MS (m/z): found, 302.2086; calcd for C20H30S, 302.2068. 1,1’-
Diadamantane-3, 3’-dithiol (32), yield 85%, white solid, mp ) 181-182
Acknowledgment. This work was supported by the
Justus-Liebig University. We thankfully acknowledge finan-
cial support from MolecularDiamond Technologies.
1
°C. H NMR: 2.17-2.04 (m, 4H), 1.91 (bs, 1H), 1.85 (bs, 3H), 1.80 (bs,
Supporting Information Available: 13C NMR spectra
for compounds 4, 6-15, 31, and 32. This material is available
free of charge via the Internet at http://pubs.acs.org.
3H), 1.73 (bs, 5H), 1.70 (s, 2H), 1.66-1.44 (m, 12H). 13C NMR: 47.1
(CH2), 45.8 (CH2), 44.3 (C), 39.3 (C), 35.5 (CH2), 33.7 (CH2), 30.6 (CH).
MS (m/z): 334 (4%), 301 (100%), 267 (3%), 167 (62%), 133 (15%), 111
(11%), 93 (19%), 79 (7%). HR-MS (m/z): found, 334.1764; calcd for
C20H30S2, 334.1789.
OL053136G
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1770
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