Concise synthesis of both diastereomers of 3-hydroxy-l-arginine

Article abstract of DOI:10.1016/j.tet.2009.10.102

The hydroxylated amino acid 3-hydroxy-l-arginine is an intermediate in the biosynthesis of the non-proteinogenic amino acid capreomycidine and possibly also of its epimer epicapreomycidine. The novel concise synthesis of 3-hydroxy-l-arginine presented her

Full text of DOI:10.1016/j.tet.2009.10.102

Tetrahedron 66 (2010) 208–214
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Tetrahedron
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Concise synthesis of both diastereomers of 3-hydroxy- -arginine
L
*
Anke Lemke, Martin Bu¨schleb, Christian Ducho
Georg-August-University Go¨ttingen, Department of Chemistry, Institute of Organic and Biomolecular Chemistry, Tammannstr. 2, 37077 Go¨ttingen, Germany
a r t i c l e i n f o
a b s t r a c t
Article history:
Received 7 October 2009
Received in revised form 28 October 2009
Accepted 29 October 2009
Available online 1 November 2009
The hydroxylated amino acid 3-hydroxy-L-arginine is an intermediate in the biosynthesis of the non-
proteinogenic amino acid capreomycidine and possibly also of its epimer epicapreomycidine. The novel
concise synthesis of 3-hydroxy- -arginine presented here allows the efficient preparation of both 3-
epimers of this -hydroxy amino acid. It also offers the potential to obtain suitably isotope-labelled
L
b
derivatives for the elucidation of epicapreomycidine assembly in the biosynthesis of complex natural
products.
Keywords:
Ó 2009 Elsevier Ltd. All rights reserved.
Amino acids
Biosynthesis
Natural products
1. Introduction
unit with structural similarities to 1 and 2 is a constituent
of the mannopeptimycins, a novel subclass of glycopeptide
Natural products with antibacterial activity are of particular
interest due to emerging resistances of bacteria towards estab-
lished antibiotics.1,2 Non-proteinogenic amino acids are often
characteristic structural motifs of such naturally occurring anti-
bacterial agents. The non-proteinogenic amino acid (2S,3R)-cap-
reomycidine (‘capreomycidine’) 1 is a constituent of natural
products such as the tuberactinomycin peptide antibiotics,3–7
e.g., the capreomycins8–12 and viomycin,13–17 which have both
found clinical use as anti-tuberculosis drugs. The 3-epimer
(2S,3S)-capreomycidine (‘epicapreomycidine’) 2 can be found as
a component of the naturally occurring protease inhibitors chy-
mostatin18,19 and elastatinal20,21 as well as a building block of the
Streptomyces-produced muraymycins, a subclass of nucleoside
lipopeptide antibiotics (Fig. 1).22 Furthermore, an amino acid
antibiotics.23–25
The biosynthesis of 1 as part of viomycin biosynthesis in
Streptomyces vinaceus has been elucidated (Scheme 1).26–28
Capreomycidine assembly commences with stereoselective 3-
hydroxylation of
2-oxoglutarate (2-OG) dependent Fe(II) oxygenase VioC, to give
(3S)-3-hydroxy- -arginine (S)-4. This -hydroxy amino acid then
undergoes ring closure to yield 1 with formal inversion of the
configuration at C-3, mediated by the pyridoxalphosphate (PLP)
dependent enzyme VioD. This reaction most likely proceeds via
intramolecular Michael-type addition of the guanidine moiety of
L-arginine 3, catalysed by the non-haeme
L
b
a
,
b
-unsaturated intermediate 5.
Figure 1. The non-proteinogenic amino acids capreomycidine
capreomycidine 2.
1
and epi-
* Corresponding author. Tel.: þ49 (0)551 39 3284; fax: þ49 (0)551 39 9660.
E-mail address: cducho@gwdg.de (C. Ducho).
Scheme 1. Biosynthesis of capreomycidine 1 in S. vinaceus.26–28
0040-4020/$ – see front matter Ó 2009 Elsevier Ltd. All rights reserved.
doi:10.1016/j.tet.2009.10.102

A. Lemke et al. / Tetrahedron 66 (2010) 208–214
209
It can be proposed that the biosynthetic assembly of epi-
capreomycidine 2 as part of the biosynthesis of complex natural
products such as muraymycin antibiotics might occur in a similar
manner. However, the stereochemical course of epicapreomycidine
were benzylated to afford (R)-8 and (S)-8 in yields of 89% and 99%,
respectively (Scheme 2). This exchange of the alcohol protecting
group was necessary as the silyl ether was concomitantly hydro-
lysed in the subsequent acidic acetonide cleavage, which
proceeded smoothly in case of the benzylated starting material to
furnish (R)-9 and (S)-9 (94% and 90% yield). These amino alcohols
were then oxidized to the corresponding amino acids using TEMPO
and bis-(acetoxy)-iodobenzene (BAIB).48 Subsequent tert-butyl
ester formation with the crude amino acids under Eschenmoser
conditions49 gave (R)-10 and (S)-10 in 61% and 57% yield,
respectively, over two steps from (R)-9 and (S)-9 (Scheme 2). Thus,
formation from L-arginine 3 is unclear. In addition, it cannot be
ruled out that epicapreomycidine 2 is formed via enzymatically
catalysed epimerisation of capreomycidine 1 at the C-3 position.
There is evidence for unusual epimerisation reactions in other
biosynthetic pathways in bacteria, most notably in the biosynthesis
of simple carbapenems,29,30 of thienamycin31 and of clavulanic
acid.30 In the case of simple carbapenem
epimerisation at the
b
-lactam antibiotics,
b
-lactam bridgehead position is mediated by
any unwanted epimerisation at the a-carbon atom, which can occur
the non-haeme 2-OG dependent Fe(II) oxygenase CarC.32–36 The
corresponding enzymes catalysing the epimerisation steps in
thienamycin and clavulanic acid biosynthesis have yet to be
identified.
when other methods such as DCC coupling are used for tert-butyl
esterification of carbamate-protected amino acids,50 was not
observed. Epimerisation at the a-carbon atom would have easily
been detectable by NMR spectroscopy at any stage of the synthetic
route due to the formation of diastereomers.
A 3-hydroxylated arginine residue also plays a key role in the
biosynthesis of clavulanic acid. Deoxyguanidino-proclavaminate,
a precursor of clavulanic acid, is stereoselectively hydroxylated
at its arginine moiety by the non-haeme 2-OG dependent Fe(II)
oxygenase clavaminate synthase (CAS).30,37–42 This implies that
For introduction of the guanidine moiety, olefins (R)-10 and (S)-
10 were cleaved by ozonolysis with reductive workup. In order to
obtain satisfactory yields of the resulting alcohols (72% of (R)-11
and 91% of (S)-11), it was essential to use a significant excess of
sodium borohydride for the reduction step. The primary products
of the ozonolysis reaction were derivatives of glutamate semi-
aldehyde, and the strong preference of the cyclic hemiaminal form,
which is typical for these compounds,50 might have slowed down
the reduction step. Alcohols (R)-11 and (S)-11 were then reacted
with tris-Cbz-guanidine 12 using Goodman’s guanidinylation
method under Mitsunobu conditions51 to afford protected guani-
dines (R)-13 and (S)-13 in 66% and 73% yield, respectively. The
3-hydroxy-L-arginine is not a direct precursor of clavulanic acid
because -lactam ring formation precedes arginine hydroxylation.
b
3-Hydroxy-arginine was also speculated to be an intermediate in
the biosynthesis of the antibiotic streptothricin F, but this
hypothesis was not confirmed.43
Studies on biosynthetic pathways employing 3-hydroxy-
nine as an intermediate require an efficient synthesis of both
diastereomers (R)-4 and (S)-4 of this -hydroxy amino acid with the
potential to prepare suitably isotope-labelled derivatives (Fig. 2). So
far, there is only one synthesis of 3-hydroxy-
-arginine available.44
L-argi-
b
protected 3-hydroxy-L-arginines (R)-13 and (S)-13 could be
deprotected by hydrogenolysis (products (R)-14 and (S)-14, quan-
L
This established synthetic route involves a 1,3-dipolar cycloaddi-
tion reaction of a vinylglycine derivative and a nitrone as its key
step. Though this approach is very elegant, it significantly limits the
potential to incorporate isotope labels in a reasonable number of
synthetic steps. Consequently, it has only found application in the
titative yields), followed by treatment with hydrochloric acid. Thus,
diastereomerically pure 3-hydroxy-L-arginines (R)-4 and (S)-4 were
obtained as dihydrochlorides in 89% and 82% yield, respectively, for
the final deprotection step and in overall yields of 21% each over 9
steps from (R)-6 and (S)-6 (Scheme 2).
Benzyl protection of the secondary hydroxy group was
essential not only for selective oxidation of the primary alcohol,
but also for the guanidinylation reaction. Test reactions for the
guanidinylation reaction with an O-unprotected analogue of
(R)-11 and (S)-11 gave only moderate conversions and resulted in
severe purification problems. Attempts to carry out the synthetic
route with a diastereomeric mixture of 7 with separation of
diastereomers at a late stage were unsuccessful.
synthesis of 5,5-dideuterated 3-hydroxy-
L
-arginine.43
In order to verify the reported stereochemical assignment and to
elucidate steps for the incorporation of isotope labels, the estab-
lished preparation of starting materials (R)-6 and (S)-647 was
Figure 2. Target structures (R)-4 and (S)-4, the two diastereomers of 3-hydroxy-L-
arginine.
investigated more closely. The conversion of D-serine 15 to the
acetonide protected methyl ester 16 is known as is transformation
of the latter to the (R)-configured Garner aldehyde 17.52,53 Aldehyde
17 can then be employed for the synthesis of starting material 6 by
addition of allylmagnesium chloride and silyl protection according
to the previously published procedure. The two diastereomers of 6
can be readily separated by column chromatography as reported.47
However, the assignment of the absolute configuration at the newly
formed stereocenter of the fast eluting major diastereomer (R)-6
was solely based on NMR data of the Mosher ester derivative of
desilylated alcohol (R)-7.47 In order to ensure that this assignment
is correct, it was envisaged to prepare cyclic analogues of both
desilylated diastereomers (R)-7 and (S)-7 suitable for nuclear
Overhauser enhancement (NOE) NMR experiments. Using a trans-
formation similar to a previously described reaction,54 diaster-
eomerically pure alcohols (R)-7 and (S)-7 were treated with triflic
anhydride (Tf2O). The formed triflates were not stable, but
underwent spontaneous intramolecular SN2-type nucleophilic
attack most likely by the carbonyl oxygen atom of the Boc group
More detailed investigations e.g., on epicapreomycidine
assembly in muraymycin biosynthesis would require additional
labelled analogues of (R)-4 and (S)-4, particularly doubly labelled
compounds and/or derivatives with a deuterium label at the C-3
position as chemical probes for a possible epimerisation pathway
(vide supra). In this work, we describe a facile synthesis of both (R)-
4 and (S)-4 in diastereomerically pure form, bearing the potential to
introduce isotope labels at several positions including C-3.
2. Results and discussion
In contrast to the known cycloaddition route, our novel
approach utilises the established diastereomerically pure silylated
homoallylic alcohols (R)-6 and (S)-6 as starting materials, which
can be readily prepared from Garner’s aldehyde45,46 as previously
reported (vide infra).47 Desilylation of both (R)-6 and (S)-6 gave
homoallylic alcohols (R)-7 and (S)-7 (96% and 75% yield), which

210
A. Lemke et al. / Tetrahedron 66 (2010) 208–214
Scheme 2. Synthesis of target compounds (R)-4 and (S)-4 from diastereomerically pure silylated homoallylic alcohols (R)-6 and (S)-6.
with inversion of the stereochemical configuration and rupture of
the tert-butyl-oxygen bond. However, it is unclear if the ring clo-
sure reaction occurred immediately after formation of the triflate or
upon aqueous workup. Thus, cyclic carbamates (S)-18 and (R)-18
were formed from (R)-7 and (S)-7, respectively, in isolated yields of
91% and 47% without optimisation of the reaction conditions
(Scheme 3).
importantly, reduction of 16 to 17 (Scheme 3) using deuterated
reducing agents such as DIBAL-D or commercially available lithium
aluminium deuteride (followed by Swern oxidation) would finally
lead to a deuterium label at the 3-position of 4. Application of so-
dium borodeuteride in the reductive workup of the ozonolysis
reaction yielding intermediate 11 (Scheme 2) enables the in-
troduction of an additional deuterium label at the 5-position of 4.
Furthermore, labelled derivatives of allyl bromide and allyl alcohol
are commercially available. If a Grignard reagent was prepared
from either of these compounds for the addition reaction leading to
7 (Scheme 3), introduction of deuterium or 13C labels at the 4-po-
sition of 4 would be feasible.
3. Summary
In conclusion, a concise synthesis of both diastereomers of 3-
hydroxy-
hyde 17 was developed. An established silylated homoallylic alcohol
6 derived from 17 was employed for conversion into -hydroxy
L-arginine 4 starting from the (R)-configured Garner alde-
b
amino acid 10. Further transformation of 10, including guanidiny-
lation under Mitsunobu conditions, led to stereoisomerically pure
target compounds (R)-4 and (S)-4 in overall yields of 21% each over
nine steps from (R)-6 and (S)-6 (Scheme 2). The overall yields
starting from the (R)-configured Garner aldehyde 17 were 10% of (R)-
4 and 4% of (S)-4, respectively, over 11 steps. This novel synthesis of
3-hydroxy-L-arginine 4 is suitable for the preparation of multiply
isotope-labelled derivatives. Since 4 is a known intermediate in the
biosynthesis of the non-proteinogenic amino acid capreomycidine 1,
labelled derivatives of 4 might enable the elucidation of the
biosynthetic assembly of the 3-epimer of 1, epicapreomycidine 2, in
the biosynthesis of complex natural products such as muraymycin
nucleoside antibiotics.
Scheme 3. Synthesis of carbamates 18 for NOE 1H NMR studies.
The cis and trans substitution patterns of the cyclic moieties of
(S)-18 and (R)-18 were proven by 1D NOE 1H NMR studies. There
was a strong NOE for the two protons attached to the fused five-
membered ring of the cis-isomer (S)-18, but only a very weak NOE
was found for the corresponding two protons of the trans-isomer
(R)-18 (Scheme 3).55 Hence, the proposed stereochemical configu-
ration of both cyclic carbamates (S)-18 and (R)-18 and therefore
also of the desilylated alcohols (R)-7 and (S)-7 could be unambi-
gously confirmed.
4. Experimental
4.1. General
Chemicals were purchased from Sigma–Aldrich, Alfa Aesar,
ABCR and VWR. Diastereomerically pure starting materials (R)-6
and (S)-6 were synthesised as previously reported.47 Ozone was
generated using a Fischer ozone generator model 502. Reactions
involving oxygen and/or moisture sensitive reagents were carried
out under an atmosphere of argon using anhydrous solvents. An-
hydrous solvents were obtained in the following manner: THF was
dried over sodium/benzophenone and distilled, CH2Cl2 was dried
The novel synthetic route towards stereoisomerically pure
3-hydroxy-L-arginine 4 reported here permits incorporation of
isotope labels for biosynthetic studies at multiple sites. Most

A. Lemke et al. / Tetrahedron 66 (2010) 208–214
211
over CaCl2 and distilled and pyridine was dried over CaH2 and
distilled. All other solvents were of technical quality and distilled
prior to their use, and distilled water was used throughout.
Column chromatography was carried out on silica gel 60 (0.040–
0.063 mm, 230–400 mesh ASTM, VWR) except where indicated
under flash conditions. TLC was performed on aluminium plates
precoated with silica gel 60 F254 (VWR). Visualisation of the spots
was carried out using UV light (254 nm) where appropriate and/or
KMnO4 staining under heating (staining solution: 1 g KMnO4,
6 g K2CO3 and 1.5 mL 5% NaOH(aq) (w/v), all dissolved in 100 mL
H2O). Rf values are given to the nearest 0.05.
2H), 4.41 (d, J¼6.0 Hz, 1H), 4.00 (dd, J¼8.5, 2.0 Hz, 1H), 3.84 (dd,
J¼8.5, 6.5 Hz,1H), 3.79–3.65 (m, 2H), 2.24–2.03 (m, 2H),1.49 (s, 3H),
13
1.45 (s, 9H), 1.45 (s, 3H); C NMR (75 MHz, DMSO-d6, 100 ꢀC)
d
151.4, 135.6, 115.4, 92.8, 78.6, 69.6, 63.0, 60.6, 38.2, 27.6, 26.1, 23.6;
MS (ESI) m/z 294.2 (MþNaþ); MS (ESI-HR) m/z calcd for
C14H25NNaO4 294.1676 (MþNaþ), found 294.1676 (MþNaþ); mp
37 ꢀC; [ 20 15.7 (c 0.95, CHCl3); IR (KBr)
a] n 3442, 2981, 2375, 1699,
D
1394, 1256, 1174, 1098, 913, 843, 768; TLC Rf value 0.25 (petroleum
ether/EtOAc 3:1).
4.2.3. N-Boc-(4R,10R)-(10-benzyloxy-30-butenyl)-2,2-dimethyl-1,3-
oxazolidine ((R)-8). To a suspension of sodium hydride (60% dis-
persion in mineral oil, 1.03 g, 25.8 mmol) in THF (40 mL), a solution
of (R)-7 (5.38 g, 19.8 mmol) in THF (60 mL) was added at 0 ꢀC, and
the mixture was stirred at 0 ꢀC for 30 min. After addition of tetra-n-
butyl-ammonium iodide (1.46 g, 3.97 mmol) and benzyl bromide
(7.1 mL, 10 g, 59 mmol), the reaction mixture was heated under
reflux for 12 h and the reaction then quenched by addition of sat-
urated aqueous NH4Cl solution (50 mL). The aqueous layer was
extracted with Et2O (3ꢂ50 mL). The combined organics were
washed with brine (2ꢂ50 mL), dried over Na2SO4 and the solvent
removed under reduced pressure. The resultant crude product was
purified by column chromatography (petroleum ether/EtOAc 20:1)
to yield (R)-8 (6.36 g, 89%) as a yellowish oil. 1H NMR (300 MHz,
300 MHz- and 600 MHz-1H as well as 75 MHz-, 76 MHz and
126 MHz-13C NMR spectra were recorded on Varian UNITY 300,
MERCURY 300, INOVA 500 and INOVA 600 spectrometers. All 13C
NMR spectra are 1H-decoupled. All spectra were recorded at room
temperature except of samples in DMSO-d6 and D2O (standard
35 ꢀC). Some spectra were recorded at 100 ꢀC in order to overcome
Boc rotamer formation. All NMR spectra were referenced internally
to solvent reference frequencies. Chemical shifts (d) are quoted in
parts per million. Coupling constants (J) are reported in Hertz to the
nearest 0.5 Hz. Assignment of signals was carried out using 1H,1H-
COSY and HSQC spectra obtained on the spectrometers mentioned
above. Low resolution ESI mass spectrometry was performed on
a Varian MAT 311 A spectrometer operating in positive ionisation
mode. High resolution (HR) ESI mass spectrometry was carried out
on a Bruker microTOF spectrometer or a Bruker 7 T FTICR APEX IV
spectrometer. Melting points (mp) were measured on a Bu¨chi in-
strument and are not corrected. Optical rotations were recorded on
a Perkin–Elmer 241 polarimeter with a Na source using a 10 cm cell.
Infrared (IR) spectroscopy was performed on a Perkin–Elmer
Spectrum BX spectrometer with liquids and oils being measured as
DMSO-d6, 100 ꢀC)
d 7.40–7.21 (m, 5H), 5.97–5.81 (m, 1H), 5.14–4.99
(m, 2H), 4.67–4.51 (m, 2H), 4.15 (ddd, J¼6.5, 4.5, 2.5 Hz, 1H), 4.00
(dd, J¼9.5, 2.5 Hz, 1H), 3.93 (dd, J¼9.5, 6.5 Hz, 1H), 3.86 (ddd, J¼8.5,
4.5, 4.0 Hz, 1H), 2.40–2.29 (m, 1H), 2.28–2.15 (m, 1H), 1.54 (s, 3H),
13
1.43 (s, 3H), 1.43 (s, 9H); C NMR (75 MHz, DMSO-d6, 100 ꢀC)
d
151.3, 138.3, 135.4, 127.5, 126.8, 126.7, 115.6, 93.2, 78.9, 77.7, 71.1,
62.8, 57.2, 33.1, 27.5, 25.8, 22.7; MS (ESI) m/z 384.2 (MþNaþ); MS
films on NaCl plates and solids as KBr pills. Wavenumbers (
n
) are
(ESI-HR) calcd for C21H31NNaO4 384.2145 (MþNaþ), found
20
quoted in cmꢁ1. UV spectroscopy was carried out on a Perkin–Elmer
Lambda-2 spectrometer. Wavelengths of maximum absorption
384.2145 (MþNaþ); [
a
]
þ17.7 (c 1.1, CHCl3); IR (film)
n 3395, 2980,
D
2345, 1703, 1455, 1387, 1256, 1171, 1090, 854, 737, 698; UV (MeCN)
(lmax) are reported in nm with the corresponding logarithmic
lmax (log 3) 258 (1.42), 204 (3.04); TLC Rf value 0.45 (petroleum
molar extinction coefficient (log
3) given in brackets.
ether/EtOAc 5:1).
4.2. Syntheses
4.2.4. N-Boc-(4R,10S)-(10-benzyloxy-30-butenyl)-2,2-dimethyl-1,3-
oxazolidine ((S)-8). Isomer (S)-8 was prepared in the same way as
compound (R)-8 with (S)-7 (3.50 g, 12.9 mmol), sodium hydride
(60% dispersion in mineral oil, 671 mg, 16.8 mmol), tetra-n-butyl-
ammonium iodide (953 mg, 2.58 mmol), benzyl bromide (4.6 mL,
6.6 g, 39 mmol) and THF (30 mL and 50 mL, respectively). The
product (S)-8 (4.61 g, 99%) was obtained as a yellowish oil. 1H NMR
4.2.1. N-Boc-(4R,10R)-(10-hydroxy-30-butenyl)-2,2-dimethyl-1,3-ox-
azolidine ((R)-7). To a solution of (R)-6 (7.98 g, 20.7 mmol) in THF
(50 mL), a solution of tetra-n-butyl-ammonium fluoride (16.3 g,
51.7 mmol) in THF (60 mL) was added at room temperature. After
stirring at room temperature for 2 h, the reaction mixture was
partitioned between water (200 mL) and Et2O (350 mL). The or-
ganic layer was washed with saturated aqueous NaHCO3 solution
(3ꢂ200 mL) and brine (1ꢂ200 mL), dried over Na2SO4 and the
solvent removed under reduced pressure. The resultant crude
product was purified by column chromatography (petroleum ether/
EtOAc 3:1) to yield (R)-7 (5.40 g, 96%) as a colourless oil. 1H NMR
(300 MHz, DMSO-d6, 100 ꢀC)
d 7.40–7.21 (m, 5H), 5.92–5.76 (m, 1H),
5.16–5.00 (m, 2H), 4.60 (d, J¼11.5 Hz, 1H), 4.53 (d, J¼11.5 Hz, 1H),
4.05–3.87 (m, 4H), 2.40–2.15 (m, 2H), 1.47 (s, 3H), 1.45 (s, 12H); 13C
NMR (75 MHz, DMSO-d6, 100 ꢀC)
d 151.3, 138.2, 134.5, 127.5, 126.9,
126.7, 116.2, 93.0, 78.8, 76.9, 71.4, 62.5, 59.1, 35.7, 27.6, 25.6, 23.9;
MS (ESI) m/z 384.2 (MþNaþ); MS (ESI-HR) m/z calcd for
20
(300 MHz, DMSO-d6,100 ꢀC)
d
5.98–5.81 (m,1H), 5.12–4.97 (m, 2H),
C21H31NNaO4 384.2145 (MþNaþ), found 384.2151 (MþNaþ); [
a]
D
4.41 (d, J¼3.5 Hz, 1H), 4.05–3.83 (m, 4H), 2.30–2.15 (m, 1H),
þ43.4 (c 1.0, CHCl3); IR (film)
n 3483, 2979, 2361, 1698, 1454, 1366,
1257, 1096, 858, 763, 698; UV (MeCN) lmax (log 3) 258 (1.29), 204
2.14–1.97 (m, 1H), 1.53 (s, 3H), 1.44 (s, 9H), 1.42 (s, 3H); 13C NMR
(75 MHz, DMSO-d6,100 ꢀC)
d
151.7,136.0,115.2, 93.1, 78.8, 69.1, 62.8,
(2.99); TLC Rf value 0.45 (petroleum ether/EtOAc 5:1).
60.2, 35.1, 27.6, 25.8, 22.9; MS (ESI) m/z 294.2 (MþNaþ); MS
(ESI-HR) m/z calcd for C14H25NNaO4 294.1676 (MþNaþ), found
4.2.5. N-Boc-3-O-benzyl-(2R,3R)-2-amino-hex-5-en-1,3-diol
((R)-
20
294.1678 (MþNaþ); [
a
]
þ25.7 (c 1.1, CHCl3); IR (film)
n
3403, 2983,
9). A solution of (R)-8 (6.25 g,17.3 mmol) in acetic acid (130 mL) and
H2O (26 mL) was stirred at room temperature for 48 h. The solvent
was removed under reduced pressure. The resultant crude product
was purified by column chromatography (petroleum ether/EtOAc
2:1) to yield (R)-9 (5.24 g, 94%) as a colourless oil. 1H NMR (300 MHz,
D
2359, 1699, 1390, 1367, 1253, 1168, 1059, 850, 765; TLC Rf value 0.25
(petroleum ether/EtOAc 3:1).
4.2.2. N-Boc-(4R,10S)-(10-hydroxy-30-butenyl)-2,2-dimethyl-1,3-ox-
azolidine ((S)-7). Isomer (S)-7 was prepared in the same way as
compound (R)-7 with (S)-6 (6.86 g, 17.8 mmol), tetra-n-butyl-am-
monium fluoride (10.0 g, 31.7 mmol) and THF (50 mL each). The
product (S)-7 (3.62 g, 75%) was obtained as a white solid. 1H NMR
C6D6) d 7.21–7.03 (m, 5H), 5.87–5.70 (m, 1H), 5.16–4.95 (m, 3H), 4.35
(d, J¼11.5 Hz, 1H), 4.17 (d, J¼11.5 Hz, 1H), 3.99–3.86 (m, 1H),
3.66–3.47 (m, 3H), 2.39–2.19 (m, 2H), 1.40 (s, 9H); 13C NMR (75 MHz,
C6D6)
d 156.5, 138.7, 134.6, 128.6, 128.1, 127.9, 117.8, 79.1, 77.8, 72.4,
(300 MHz, DMSO-d6, 100 ꢀC)
d
5.94–5.78 (m, 1H), 5.09–4.96 (m,
63.4, 54.4, 35.9, 28.4; MS (ESI) m/z 344.2 (MþNaþ); MS (ESI-HR) m/z

212
A. Lemke et al. / Tetrahedron 66 (2010) 208–214
calcd for C18H27NNaO4 344.1832 (MþNaþ), found 344.1839
128.4, 128.1, 127.9, 117.6, 81.7, 80.4, 79.3, 72.0, 56.5, 36.0, 28.3, 27.9;
20
(MþNaþ); [
a]
ꢁ4.5 (c 1.1, CHCl3); IR (film)
n
3417, 2978, 2359, 1697,
MS (ESI) m/z 414.0 (MþNaþ); MS (ESI-HR) m/z calcd for
D
20
1499, 1367, 1057, 917, 748, 699; UV (MeCN) lmax (log
3) 258 (1.48),
C22H33NNaO5 414.2251 (MþNaþ), found 414.2255 (MþNaþ); [
a]
D
204 (2.93); TLC Rf value 0.25 (petroleum ether/EtOAc 2:1).
þ10.1 (c 0.96, CHCl3); IR (film)
n 3379, 2972, 2345, 1717, 1498, 1367,
1155, 1100, 913, 732, 698; UV (MeCN) lmax (log 3) 258 (1.31), 204
4.2.6. N-Boc-3-O-benzyl-(2R,3S)-2-amino-hex-5-en-1,3-diol
((S)-
(2.94); TLC Rf value 0.20 (petroleum ether/EtOAc 12:1).
9). Isomer (S)-9 was prepared in the same way as compound (R)-9
with (S)-8 (4.57 g, 12.6 mmol), acetic acid (100 mL) and H2O
(20 mL). The product (S)-9 (3.66 g, 90%) was obtained as a colour-
4.2.9. N-Boc-3-O-benzyl-(2S,3R)-2-amino-3,5-dihydroxy-valeric
acid tert-butyl ester ((R)-11). A solution of (R)-10 (3.71 g,
9.48 mmol) in MeOH (175 mL), CH2Cl2 (20 mL) and pyridine
(3.1 mL) was cooled to ꢁ78 ꢀC, and ozone was bubbled through this
solution at ꢁ78 ꢀC for 1 h. After the addition of dimethyl sulfide
(8.0 mL, 6.7 g, 0.11 mol), the reaction was allowed to warm to room
temperature overnight. The solvent was removed under reduced
pressure, and the resultant crude aldehyde was immediately dis-
solved in MeOH (50 mL). Sodium borohydride (5.76 g, 152 mmol)
was added portionwise to this solution at 0 ꢀC, and the reaction
mixture was stirred at room temperature for 5 h and the reaction
monitored by TLC (petroleum ether/EtOAc 2:1). Following com-
plete conversion, the reaction was quenched by addition of
saturated aqueous NH4Cl solution, and the aqueous layer was
extracted with EtOAc (3ꢂ150 mL). The combined organics were
washed with H2O (2ꢂ100 mL), dried over Na2SO4 and the solvent
removed under reduced pressure. The resultant crude product was
purified by column chromatography (petroleum ether/EtOAc 2:1)
to yield (R)-11 (2.69 g, 72%) as a yellowish oil. 1H NMR (300 MHz,
less oil. 1H NMR (300 MHz, C6D6)
d 7.27–7.02 (m, 5H), 5.84–5.66 (m,
1H), 5.19 (d, J¼8.0 Hz, 1H), 5.08–4.94 (m, 2H), 4.32 (d, J¼11.5 Hz,
1H), 4.16 (d, J¼11.5 Hz, 1H), 3.88–3.73 (m, 2H), 3.66–3.47 (m, 2H),
2.36–2.04 (m, 2H), 1.42 (s, 9H); 13C NMR (75 MHz, C6D6)
d 156.1,
138.7, 134.6, 128.6, 128.0, 127.9, 117.6, 80.4, 79.1, 72.4, 62.1, 54.0,
35.9, 28.4; MS (ESI) m/z 344.2 (MþNaþ); MS (ESI-HR) m/z calcd for
20
C18H27NNaO4 344.1832 (MþNaþ), found 344.1832 (MþNaþ); [
a]
D
þ35.7 (c 1.1, CHCl3); IR (film)
n 3439, 2972, 2439, 1693, 1497, 1367,
1170, 1058, 913, 738, 698; UV (MeCN) lmax (log 3) 258 (1.24), 204
(2.94); TLC Rf value 0.25 (petroleum ether/EtOAc 2:1).
4.2.7. N-Boc-O-benzyl-(2S,3R)-2-amino-3-hydroxy-5-hexenoic acid
tert-butyl ester ((R)-10). A mixture of (R)-9 (5.17 g, 16.1 mmol), bis-
(acetoxy)-iodobenzene (BAIB, 11.4 g, 35.4 mmol) and TEMPO
(755 mg, 4.83 mmol) in MeCN (50 mL) and H2O (50 mL) was stirred
at room temperature for 3 h, and then Et2O (200 mL) was added.
The reaction mixture was extracted with saturated aqueous
NaHCO3 solution and the aqueous layer acidified with 2 N HCl
(200 mL) and extracted with EtOAc (4ꢂ200 mL). The combined
organics of this extraction were dried over Na2SO4 and the solvent
removed under reduced pressure. The resultant crude product
(5.25 g of a brown oil) was used for the subsequent esterification
reaction without purification. A solution of this crude product
(5.11 g) and tert-butanol (19 mL, 15 g, 0.20 mol) in toluene (100 mL)
was heated to reflux, and then N,N-dimethylformamide dineo-
pentylacetal (12 mL, 9.9 g, 43 mmol) was added dropwise under
reflux over 30 min. After further stirring for 5 h under reflux, the
reaction mixture was cooled to room temperature, washed with
saturated aqueous Na2CO3 solution (2ꢂ100 mL) and H2O
(2ꢂ100 mL), dried over Na2SO4 and the solvent removed under
reduced pressure. The resultant crude product was purified by
column chromatography (petroleum ether/EtOAc 12:1) to yield (R)-
10 (3.82 g, 61% over two steps from (R)-9) as a yellowish oil. 1H NMR
C6D6)
d
7.30–7.02 (m, 5H), 5.54 (d, J¼9.5 Hz, 1H), 4.73 (dd, J¼9.5,
2.0 Hz, 1H), 4.42 (s, 2H), 4.25 (ddd, J¼8.5, 6.5, 2.0 Hz, 1H), 3.51 (t,
J¼5.5 Hz, 2H), 1.86–1.58 (m, 2H), 1.38 (s, 9H), 1.29 (s, 9H); 13C NMR
(126 MHz, C6D6)
d 170.5, 156.5, 138.6, 128.5, 128.3, 127.9, 81.6, 79.6,
78.3, 72.6, 59.5, 57.7, 34.2, 28.5, 28.1; MS (ESI) m/z 418.2 (MþNaþ);
MS (ESI-HR) m/z calcd for C21H33NNaO6 418.2200 (MþNaþ), found
20
418.2200 (MþNaþ); [
a
]
þ27.1 (c 1.1, CHCl3); IR (film)
n 3433, 2972,
D
2359, 1717, 1498, 1368, 1155, 1069, 847, 748, 698; UV (MeCN) lmax
(log 3) 204 (2.98); TLC Rf value 0.15 (petroleum ether/EtOAc 2:1).
4.2.10. N-Boc-3-O-benzyl-(2S,3S)-2-amino-3,5-dihydroxy-valeric
acid tert-butyl ester ((S)-11). Isomer (S)-11 was prepared in the
same way as compound (R)-11 with (S)-10 (2.38 g, 6.08 mmol),
MeOH (100 mL), CH2Cl2 (12 mL), pyridine (2.0 mL), dimethyl sulfide
(4.5 mL, 3.8 g, 61 mmol), sodium borohydride (4.14 g, 109 mmol)
and MeOH (30 mL). The product (S)-11 (2.18 g, 91%) was obtained as
(300 MHz, C6D6)
d
7.26–7.02 (m, 5H), 5.83–5.67 (m, 1H), 5.42 (d,
a yellowish oil. 1H NMR (300 MHz, C6D6)
d 7.31–7.02 (m, 5H), 5.59
J¼10.0 Hz, 1H), 5.13–4.96 (m, 2H), 4.69 (dd, J¼10.0, 2.0 Hz, 1H), 4.38
(d, J¼11.5 Hz, 1H), 4.31 (d, J¼11.5 Hz, 1H), 4.01 (ddd, J¼8.0, 6.0,
2.0 Hz, 1H), 2.42–2.21 (m, 2H), 1.41 (s, 9H), 1.29 (s, 9H); 13C NMR
(d, J¼8.0 Hz,1H), 4.85 (dd, J¼8.0, 3.0 Hz, 1H), 4.62 (d, J¼11.5 Hz, 1H),
4.32 (d, J¼11.5 Hz, 1H), 4.02 (ddd, J¼10.0, 5.5, 3.0 Hz, 1H), 3.61 (t,
J¼5.5 Hz, 2H), 1.86–1.63 (m, 2H), 1.38 (s, 9H), 1.28 (s, 9H); 13C NMR
(75 MHz, C6D6)
d
170.7, 156.2, 138.5, 134.1, 128.5, 128.2, 127.8, 118.3,
(126 MHz, C6D6) d 169.6, 155.8, 138.8, 128.5, 128.3, 127.7, 82.0, 79.7,
81.3, 79.8, 79.3, 72.4, 57.0, 35.9, 28.3, 27.9; MS (ESI) m/z 414.0
78.5, 72.2, 59.5, 56.7, 34.2, 28.5, 28.0; MS (ESI) m/z 418.2 (MþNaþ);
(MþNaþ); MS (ESI-HR) m/z calcd for C22H33NNaO5 414.2251
MS (ESI-HR) m/z calcd for C21H33NNaO6 418.2200 (MþNaþ), found
20
20
(MþNaþ), found 414.2252 (MþNaþ); [
a
]
D
þ16.2 (c 1.2, CHCl3); IR
418.2211 (MþNaþ); [
a
]
þ2.8 (c 1.0, CHCl3); IR (film)
n 3395, 2972,
D
(film)
n
3451, 2980, 2357, 1722, 1497, 1368, 1154, 1074, 919, 740, 698;
2377, 1715, 1499, 1368, 1155, 1054, 847, 738, 698; UV (MeCN) lmax
UV (MeCN) lmax (log
3) 258 (1.61), 204 (2.98); TLC Rf value 0.20
(log
3) 257 (1.42), 204 (2.94); TLC Rf value 0.15 (petroleum ether/
(petroleum ether/EtOAc 12:1).
EtOAc 2:1).
0
4.2.8. N-Boc-O-benzyl-(2S,3S)-2-amino-3-hydroxy-5-hexenoic acid
tert-butyl ester ((S)-10). Isomer (S)-10 was prepared in the same
way as compound (R)-10 with (S)-9 (3.55 g, 11.1 mmol), BAIB (7.83 g,
24.3 mmol), TEMPO (518 mg, 3.31 mmol), MeCN (30 mL), H2O
(30 mL), tert-butanol (14 mL, 11 g, 0.15 mol), N,N-dimethylforma-
mide dineopentylacetal (8.5 mL, 7.0 g, 30 mmol) and toluene
(80 mL). The product (S)-10 (2.49 g, 57% over two steps from (S)-9)
4.2.11. N2-Boc-N5,N7,N7 -Tris-Cbz-3-O-benzyl-(3R)-3-hydroxy-
L-argi-
nine tert-butyl ester ((R)-13). To a solution of (R)-11 (2.59 g,
6.55 mmol) in THF (80 mL), tris-Cbz-guanidine 1251 (9.06 g,
19.7 mmol) and triphenyl phosphine (2.58 g, 9.83 mmol) were
added at room temperature. DIAD (1.93 mL, 1.99 g, 9.83 mmol) was
added dropwise at 0 ꢀC at such a rate that the reaction mixture was
completely colourless before addition of the next drop. The reaction
mixture was allowed to warm to room temperature and was stirred
overnight at room temperature. The reaction was then quenched by
addition of H2O (30 mL), and the solvent was removed under
reduced pressure. The resultant crude product was purified by
column chromatography (petroleum ether/EtOAc 3:1) to yield (R)-
was obtained as a yellowish oil. 1H NMR (300 MHz, C6D6)
d 7.32–7.03
(m, 5H), 5.97–5.81 (m, 1H), 5.45 (d, J¼8.5 Hz, 1H), 5.15–4.99 (m, 2H),
4.82 (dd, J¼8.5, 3.5 Hz,1H), 4.51 (d, J¼11.5 Hz, 1H), 4.34 (d, J¼11.5 Hz,
1H), 3.78 (ddd, J¼6.5, 6.5, 3.5 Hz, 1H), 2.46–2.29 (m, 2H), 1.39 (s, 9H),
1.27 (s, 9H); 13C NMR (75 MHz, C6D6)
d 169.7, 155.4, 138.9, 134.9,

A. Lemke et al. / Tetrahedron 66 (2010) 208–214
213
13 (3.63 g, 66%) as a colourless viscous oil. 1H NMR (300 MHz, C6D6)
stirred at room temperature for 3 h. The solvent was subsequently
removed under reduced pressure. The resultant crude product was
purified by column chromatography (RP silica gel 90 C18, H2O) to
yield (R)-4 dihydrochloride (720 mg, 89%) as a slightly yellowish
d
11.43 (s, 1H), 7.45–6.93 (m, 20H), 5.43 (d, J¼9.5 Hz, 1H), 5.29–4.71
(m, 4H), 4.90 (s, 2H), 4.74 (dd, J¼9.5, 2.0 Hz, 1H), 4.52 (d, 1H,
J¼11.5 Hz), 4.44 (d, J¼11.5 Hz, 1H), 4.21 (ddd, J¼6.5, 6.5, 2.0 Hz, 1H),
4.14–4.01 (m, 1H), 3.99–3.88 (m, 1H), 2.21–2.07 (m, 1H), 2.03–1.87
viscous oil. 1H NMR (300 MHz, D2O)
d
4.37–4.29 (m, 1H), 4.10 (d,
(m, 1H), 1.40 (s, 9H), 1.29 (s, 9H); 13C NMR (126 MHz, C6D6)
d 170.5,
J¼4.0 Hz,1H), 3.42 (t, J¼7.0 Hz, 2H), 2.09–1.96 (m,1H),1.95–1.81 (m,
156.3, 154.7, 152.3, 138.7, 135.4, 128.8, 128.7, 128.6, 128.6, 128.5,
128.5, 128.3, 128.1, 127.9, 127.6, 81.4, 79.4, 77.8, 72.2, 69.0, 68.2, 57.5,
45.1, 30.7, 28.5, 28.1; MS (ESI) m/z 861.4 (MþNaþ); MS (ESI-HR) m/z
1H); 13C NMR (126 MHz, D2O)
d 172.6, 159.3, 69.0, 60.4, 40.4, 34.7;
MS (ESI) m/z 191.1 (MþHþ); MS (ESI-HR): m/z calcd for C6H15N4O3
20
191.1139 (MþHþ), found 191.1138 (MþHþ); [
a
]
D
þ20.4 (c 1.1, H2O);
calcd for C46H54N4NaO11 861.3681 (MþNaþ), found 861.3690
IR (film) n 3329, 2357, 1735, 1661, 1505, 1406, 1246, 1097, 573; TLC Rf
20
(MþNaþ); [
a
]
D
þ5.3 (c 1.3, CHCl3); IR (film)
n
3433, 2978, 2274,
value 0.10 (i-PrOH/H2O/AcOH 5:2:1 as saturated NaCl solution).
1720, 1614, 1497, 1455, 1369, 1212, 1048, 750, 698; UV (MeCN) lmax
(log
3) 204 (3.65); TLC Rf value 0.30 (petroleum ether/EtOAc 3:1).
4.2.16. (3S)-3-Hydroxy- -arginine dihydrochloride ((S)-4). Isomer
L
(S)-4 was prepared in the same way as compound (R)-4 with (S)-14
(147 mg, 0.424 mmol) and 6 M aqueous HCl (4 mL). The product
(S)-4 dihydrochloride (91 mg, 82%) was obtained as a colourless
0
4.2.12. N2-Boc-N5,N7,N7 -tris-Cbz-3-O-benzyl-(3S)-3-hydroxy-
L
-argi-
nine tert-butyl ester ((S)-13). Isomer (S)-13 was prepared in the
same way as compound (R)-13 with (S)-11 (2.05 g, 5.18 mmol), tris-
Cbz-guanidine 1251 (7.17 g, 15.5 mmol), triphenyl phosphine
(2.04 g, 7.77 mmol), DIAD (1.53 mL, 1.57 g, 7.77 mmol) and THF
(60 mL). The product (S)-13 (3.19 g, 73%) was obtained as a colour-
viscous oil. 1H NMR (300 MHz, D2O)
d
4.31–4.22 (m, 1H), 4.19–4.11
(m, 1H), 3.52–3.32 (m, 2H), 2.08–1.80 (m, 2H); 13C NMR (126 MHz,
D2O)
d 172.3, 159.4, 69.5, 60.7, 40.6, 33.5; MS (ESI) m/z 191.1
(MþHþ); MS (ESI-HR) m/z calcd for C6H15N4O3 191.1139 (MþHþ),
less viscous oil. 1H NMR (300 MHz, C6D6)
d
11.39 (s, 1H), 7.46–6.94
found 191.1145 (MþHþ); [
a]
ꢁ1.2 (c 1.0, H2O); IR (film)
n 3285,
20
D
(m, 20H), 5.37 (d, J¼8.5 Hz, 1H), 5.22–4.73 (m, 4H), 4.93 (dd, J¼8.5,
3.5 Hz, 1H), 4.86 (s, 2H), 4.70 (d, 1H, J¼11.0 Hz), 4.36 (d, J¼11.0 Hz,
1H), 4.07–3.91 (m, 3H), 2.05–1.79 (m, 2H), 1.36 (s, 9H), 1.30 (s, 9H);
2339, 1737, 1659, 1503, 1406, 1251, 1061, 584; TLC Rf value 0.10
(i-PrOH/H2O/AcOH 5:2:1 as saturated NaCl solution).
13C NMR (126 MHz, C6D6)
d
169.6, 155.6, 154.8, 151.8, 139.0, 135.4,
4.2.17. (S)-Configured cyclic carbamate ((S)-18). To a solution of (R)-
7 (115 mg, 0.424 mmol) in CH2Cl2 (8 mL) and pyridine (2 mL),
128.7, 128.6, 128.5, 128.5, 128.4, 128.3, 128.3, 127.5, 82.1, 79.4, 77.8,
71.7, 69.0, 68.2, 56.2, 45.5, 30.0, 28.5, 28.0; MS (ESI) m/z 861.4
trifluoromethanesulfonic
acid
anhydride
(Tf2O,
239 mg,
(MþNaþ); MS (ESI-HR) m/z calcd for C46H54N4NaO11 861.3681
0.849 mmol) was slowly added at 0 ꢀC. The reaction mixture was
stirred at 0 ꢀC for 1 h and monitored by TLC (petroleum ether/EtOAc
1:1) for complete consumption of the starting material. The
reaction mixture was then washed with 1 M HCl (10 mL) and H2O
(10 mL), dried over Na2SO4 and the solvent removed under reduced
pressure. The resultant crude product was purified by column
chromatography (petroleum ether/EtOAc 5:1) to yield (S)-18
20
(MþNaþ), found 861.3681 (MþNaþ); [
a]
þ4.3 (c 0.88, CHCl3); IR
D
(film)
n 3379, 2972, 2359, 1717, 1610, 1454, 1366, 1210, 1048, 750,
697; UV (MeCN) lmax (log 3) 204 (3.64); TLC Rf value 0.30 (petro-
leum ether/EtOAc 3:1).
4.2.13. N2-Boc-(3R)-3-hydroxy-
L-arginine tert-butyl ester ((R)-
14). To a solution of (R)-13 (3.51 g, 4.18 mmol) in MeOH (50 mL),
20% Pd(OH)2/C (Pearlman’s catalyst, 586 mg, 0.840 mmol) was
added, and the reaction mixture was stirred under an atmosphere
of hydrogen (1 bar) at room temperature for 19 h. It was sub-
sequently filtered through Celite and the Celite washed thoroughly
with MeOH. The solvent of the filtrate was removed under reduced
pressure to yield (R)-14 (1.47 g, quant.) as a colourless solid. 1H NMR
(76 mg, 91%) as a yellowish oil. 1H NMR (600 MHz, DMSO-d6)
d 5.77
(ddt, J¼17.0, 10.5, 6.5 Hz, 1H), 5.22–5.08 (m, 2H), 4.73 (td, J¼8.0,
6.0 Hz, 1H), 4.42 (ddd, J¼8.5, 8.0, 6.5 Hz, 1H), 3.87 (dd, J¼8.5, 6.5 Hz,
1H), 3.74 (t, J¼8.5 Hz, 1H), 2.47–2.36 (m, 2H), 1.59 (s, 3H), 1.35 (s,
3H); 13C NMR (126 MHz, DMSO-d6)
d 151.7, 136.0, 115.2, 93.1, 78.8,
69.1, 62.8, 60.2, 35.1, 27.6, 25.8, 22.9; MS (ESI) m/z 220.1 (MþNaþ);
MS (ESI-HR) m/z calcd for C10H15NNaO3 220.0944 (MþNaþ), found
20
(300 MHz, DMSO-d6)
d
8.00–5.80 (br s, 5H), 3.98–3.84 (m, 2H),
220.0944 (MþNaþ); [
a]
þ28.9 (c 1.1, CHCl3); IR (film)
n 2989, 1747,
D
3.26–3.10 (m, 2H), 1.69–1.49 (m, 2H), 1.40 (s, 9H), 1.39 (s, 9H); 13C
1644, 1374, 1314, 1260, 1160, 1113, 1037, 812, 770; TLC Rf value 0.50
NMR (76 MHz, DMSO-d6)
d
169.9, 156.9, 155.6, 80.4, 78.3, 68.1, 59.2,
(petroleum ether/EtOAc 1:1).
37.5, 33.2, 28.0, 27.6; MS (ESI) m/z 347.2 (MþHþ); MS (ESI-HR) m/z
calcd for C15H31N4O5 347.2289 (MþHþ), found 347.2290 (MþHþ);
4.2.18. (R)-Configured cyclic carbamate ((R)-18). Isomer (R)-18 was
prepared in the same way as compound (S)-18 with (S)-7 (36 mg,
0.13 mmol), Tf2O (75 mg, 0.26 mmol), CH2Cl2 (4 mL) and pyridine
(1 mL). The product (R)-18 (12 mg, 47%) was obtained as a yellowish
20
mp 125 ꢀC; [
a
]
D
þ1.0 (c 1.0, MeOH); IR (KBr)
n 3412, 2978, 2357,
1682, 1528, 1369, 1245, 1156, 1070, 838, 705; TLC Rf value 0.45
(CH2Cl2/MeOH 2:1).
oil. 1H NMR (600 MHz, DMSO-d6)
d
5.78 (ddt, J¼17.0, 10.5, 7.0 Hz,
4.2.14. N2-Boc-(3S)-3-hydroxy-
L
-arginine tert-butyl ester ((S)-
1H), 5.17 (ddt, J¼17.0, 10.5, 1.5 Hz, 2H), 4.48 (td, J¼6.0, 5.5 Hz, 1H),
4.09 (ddd, J¼7.5, 6.5, 5.5 Hz, 1H), 4.02 (dd, J¼8.0, 6.5 Hz, 1H), 3.65
(dd, J¼8.0, 7.5 Hz, 1H), 2.52–2.46 (m, 2H), 1.58 (s, 3H), 1.34 (s, 3H);
14). Isomer (S)-14 was prepared in the same way as compound
(R)-14 with (S)-13 (3.03 g, 3.61 mmol), 20% Pd(OH)2/C (Pearlman’s
catalyst, 506 mg, 0.720 mmol) and MeOH (40 mL). The product
(S)-14 (1.34 g, quant.) was obtained as a colourless solid. 1H NMR
13C NMR (126 MHz, DMSO-d6)
d 156.2, 131.9, 118.8, 93.6, 76.7, 67.4,
62.2, 38.0, 27.3, 23.0; MS (ESI) m/z 220.1 (MþNaþ); MS (ESI-HR) m/z
(300 MHz, D2O)
d
4.17–4.07 (m, 1H), 4.05–3.94 (m, 1H), 3.41–3.29
calcd for C10H15NNaO3 220.0944 (MþNaþ), found 220.0944
20
(m, 2H), 1.88–1.69 (m, 2H), 1.49 (s, 9H), 1.45 (s, 9H); 13C NMR
(MþNaþ); [
a
]
þ39.9 (c 0.90, CHCl3); IR (film)
n 2989, 1760, 1368,
D
(126 MHz, D2O)
d
173.4, 166.2, 159.3, 85.6, 84.1, 71.0, 62.1, 40.3,
1244, 1152, 1048, 990, 924, 816, 768; TLC Rf value 0.45 (petroleum
34.2, 30.3, 29.9; MS (ESI) m/z 347.2 (MþHþ); MS (ESI-HR) m/z
ether/EtOAc 1:1).
calcd for C15H31N4O5 347.2289 (MþHþ), found 347.2291 (MþHþ);
20
mp 120 ꢀC; [
a
]
ꢁ9.4 (c 0.95, MeOH); IR (KBr)
n 3417, 2978, 2362,
D
1686, 1454, 1368, 1251, 1156, 1108, 842; TLC Rf value 0.45 (CH2Cl2/
Acknowledgements
MeOH 2:1).
We thank the Fonds der Chemischen Industrie (FCI) for financial
support. Donation of laboratory equipment by the BASF SE is
gratefully acknowledged.
4.2.15. (3R)-3-Hydroxy-
tion of (R)-14 (1.07 g, 3.09 mmol) in 6 M aqueous HCl (30 mL) was
L-arginine dihydrochloride ((R)-4). A solu-

214
A. Lemke et al. / Tetrahedron 66 (2010) 208–214
24. Singh, M. P.; Petersen, P. J.; Weiss, W. J.; Janso, J. E.; Luckman, S. W.; Lenoy, E. B.;
Supplementary data
Bradford, P. A.; Testa, R. T.; Greenstein, M. Antimicrob. Agents Chemother. 2003,
47, 62–69.
25. Koehn, F. E. J. Med. Chem. 2008, 51, 2613–2617.
26. Yin, X.; Zabriskie, T. M. ChemBioChem 2004, 5, 1274–1277.
27. Yin, X.; McPhail, K. L.; Kim, K.; Zabriskie, T. M. ChemBioChem 2004, 5,
1278–1281.
28. Ju, J.; Ozanick, S. G.; Shen, B.; Thomas, M. G. ChemBioChem 2004, 5, 1281–1285.
29. Li, R.; Stapon, A.; Blanchfield, J. T.; Townsend, C. A. J. Am. Chem. Soc. 2000, 122,
9296–9297.
1H and 13C NMR spectra of all compounds and 1D NOE 1H NMR
spectra of compounds (R)-18 and (S)-18. Supplementary data
associated with this article can be found in the online version, at
doi:10.1016/j.tet.2009.10.102.
References and notes
30. Kershaw, N. J.; Caines, M. E. C.; Sleeman, M. C.; Schofield, C. J. Chem. Commun.
2005, 4251–4263.
31. Hamed, R. B.; Batchelar, E. T.; Mecinovic´, J.; Claridge, T. D. W.; Schofield, C. J.
ChemBioChem 2009, 10, 246–250.
32. Stapon, A.; Li, R.; Townsend, C. A. J. Am. Chem. Soc. 2003, 125, 15746–15747.
33. Clifton, I. J.; Doan, L. X.; Sleeman, M. C.; Topf, M.; Suzuki, H.; Wilmouth, R. C.;
Schofield, C. J. J. Biol. Chem. 2003, 278, 20843–20850.
34. Sleeman, M. C.; Smith, P.; Kellam, B.; Chhabra, S. R.; Bycroft, B. W.; Schofield, C. J.
ChemBioChem 2004, 5, 879–882.
35. Topf, M.; Sandala, G. M.; Smith, D. M.; Schofield, C. J.; Easton, C. J.; Radom, L. J.
Am. Chem. Soc. 2004, 126, 9932–9933.
1. Taubes, G. Science 2008, 321, 356–361.
2. Butler, M. S.; Buss, A. D. Biochem. Pharmacol. 2006, 71, 919–929.
3. Nagata, A.; Ando, T.; Izumi, R.; Sakakibara, H.; Take, T.; Hayano, K.; Abe, J. J.
Antibiot. 1968, 21, 681–687.
4. Wakamiya, T.; Shiba, T.; Kaneko, T.; Sakakibara, H.; Take, T.; Abe, J. Tetrahedron
Lett. 1970, 11, 3497–3500.
5. Yoshioka, H.; Aoki, T.; Goko, H.; Nakatsu, K.; Noda, T.; Sakakibara, H.; Take, T.;
Nagata, A.; Abe, J.; Wakamiya, T.; Shiba, T.; Kaneko, T. Tetrahedron Lett. 1971, 12,
2043–2046.
36. Borowski, T.; Broclawik, E.; Schofield, C. J.; Siegbahn, P. E. M. J. Comput. Chem.
2006, 27, 740–748.
6. Ando, T.; Matsuura, K.; Izumi, R.; Noda, T.; Take, T.; Nagata, A.; Abe, J. J. Antibiot.
1971, 24, 680–686.
37. Baldwin, J. E.; Lloyd, M. D.; Wha-Son, B.; Schofield, C. J.; Elson, S. W.; Baggaley,
K. H.; Nicholson, N. H. J. Chem. Soc., Chem. Commun. 1993, 500–502.
38. Baldwin, J. E.; Merritt, K. D.; Schofield, C. J.; Elson, S. W.; Baggaley, K. H. J. Chem.
Soc., Chem. Commun. 1993, 1301–1302.
39. Baldwin, J. E.; Lee, V.; Lloyd, M. D.; Schofield, C. J.; Elson, S. W.; Baggaley, K. H. J.
Chem. Soc., Chem. Commun. 1993, 1694–1696.
40. Janc, J. W.; Egan, L. A.; Townsend, C. A. J. Biol. Chem. 1995, 270, 5399–5404.
41. Busby, R. W.; Townsend, C. A. Bioorg. Med. Chem. 1996, 4, 1059–1064.
42. Lloyd, M. D.; Merritt, K. D.; Lee, V.; Sewell, T. J.; Wha-Son, B.; Baldwin, J. E.;
Schofield, C. J.; Elson, S. W.; Baggaley, K. H.; Nicholson, N. H. Tetrahedron 1999,
55, 10201–10220.
43. Gould, S. J.; Lee, J.; Wityak, J. Bioorg. Chem. 1991, 19, 333–350.
44. Wityak, J.; Gould, S. J.; Hein, S. J.; Keszler, D. A. J. Org. Chem. 1987, 52, 2179–2183.
45. Garner, P. Tetrahedron Lett. 1984, 25, 5855–5858.
7. Izumi, R.; Noda, T.; Ando, T.; Take, T.; Nagata, A. J. Antibiot. 1972, 25, 201–207.
8. Herr, E. B.; Haney, M. E.; Pittenger, G. E.; Higgens, C. E. Proc. Ind. Acad. Sci. 1960,
69, 134.
9. Bycroft, B. W.; Cameron, D.; Croft, L. R.; Hassanali-Walji, A.; Johnson, A. W.;
Webb, T. Nature 1971, 231, 301–302.
10. Shiba, T.; Nomoto, S.; Teshima, T.; Wakamiya, T. Tetrahedron Lett. 1976, 17,
3907–3910.
11. Nomoto, S.; Teshima, T.; Wakamiya, T.; Shiba, T. J. Antibiot. 1977, 30, 955–959.
12. Nomoto, S.; Teshima, T.; Wakamiya, T.; Shiba, T. Tetrahedron 1978, 34, 921–927.
13. Finlay, A. C.; Hobby, G. L.; Hochstein, F.; Lees, T. M.; Lenert, T. F.; Means, J. A.;
P’An, S. Y.; Regna, P. P.; Routien, J. B.; Sobin, B. A.; Tate, K. B.; Kane, J. H. Am. Rev.
Tuberculosis 1951, 63, 1–3.
14. Bartz, Q. R.; Ehrlich, J.; Mold, J. D.; Penner, M. A.; Smith, R. M. Am. Rev. Tuber-
culosis 1951, 63, 4–6.
46. Garner, P.; Ramakanth, S. J. Org. Chem. 1986, 51, 2609–2612.
47. Jackson, M. D.; Gould, S. J.; Zabriskie, T. M. J. Org. Chem. 2002, 67, 2934–2941.
48. De Mico, A.; Margarita, R.; Parlanti, L.; Vescovi, A.; Piancatelli, G. J. Org. Chem.
1997, 62, 6974–6977.
49. Brechbu¨hler, H.; Bu¨chi, H.; Hatz, E.; Schreiber, J.; Eschenmoser, A. Helv. Chim.
Acta 1965, 48, 1746–1771.
15. Dyer, J. R.; Kellogg, C. K.; Nassar, R. F.; Streetman, W. E. Tetrahedron Lett. 1965, 6,
585–592.
16. Bycroft, B. W.; Croft, L. R.; Johnson, A. W.; Webb, T. J. Antibiot. 1969, 22, 133–134.
17. Noda, T.; Take, T.; Nagata, A.; Wakamiya, T.; Shiba, T. J. Antibiot. 1972, 25, 427–428.
18. Umezawa, H.; Aoyagi, T.; Morishima, H.; Kunimoto, S.; Matsuzaki, M.; Hamada,
M.; Takeuchi, T. J. Antibiot. 1970, 23, 425–427.
50. Ducho, C.; Hamed, R. B.; Batchelar, E. T.; Sorensen, J. L.; Odell, B.; Schofield, C. J.
Org. Biomol. Chem. 2009, 7, 2770–2779.
19. Tatsuta, K.; Mikami, N.; Fujimoto, K.; Umezawa, S.; Umezawa, H.; Aoyagi, T. J.
Antibiot. 1973, 26, 625–646.
51. Feichtinger, K.; Sings, H. L.; Baker, T. J.; Matthews, K.; Goodman, M. J. Org. Chem.
1998, 63, 8432–8439.
20. Umezawa, H.; Aoyagi, T.; Okura, A.; Morishima, H.; Takeuchi, T.; Okami, Y. J.
Antibiot. 1973, 26, 787–789.
52. Garner, P.; Park, J. M. J. Org. Chem. 1987, 52, 2361–2364.
53. Dondoni, A.; Perrone, D. Org. Synth. 2000, 77, 64–77.
54. De Jonghe, S.; Van Overmeire, I.; Van Calenbergh, S.; Hendrix, C.; Busson, R.; De
Keukeleire, D.; Herdewijn, P. Eur. J. Org. Chem. 2000, 3177–3183.
55. A more detailed discussion of the 1D NOE 1H NMR experiments is given in the
Supplementary data.
21. Okura, A.; Morishima, H.; Takita, T.; Aoyagi, T.; Takeuchi, T.; Umezawa, H. J.
Antibiot. 1975, 28, 337–339.
22. McDonald, L.A.;Barbieri,L.R.; Carter, G.T.;Lenoy, E.;Lotvin,J.; Petersen,P. J.; Siegel,
M. M.; Singh, G.; Williamson, R. T. J. Am. Chem. Soc. 2002, 124, 10260–10261.
23. He, H.; Williamson, R. T.; Shen, B.; Graziani, E. I.; Yang, H. Y.; Sakya, S. M.;
Petersen, P. J.; Carter, G. T. J. Am. Chem. Soc. 2002, 124, 9729–9736.