Synthesis, biological evaluation and docking studies of octane-carboxamide based renin inhibitors with extended segments toward S3′ site of renin

Article abstract of DOI:10.1016/j.bmc.2011.05.059

Eighteen octane-carboxamide based renin inhibitors with extended segments for mimicking P3′ unit of angiotensinogen have been synthesized. The biological evaluation identified novel renin inhibitors with more potent activity than aliskiren. Molecular docking studies showed that the extended amide-tails matched the P3′ position of angiotensinogen and exerted interactions with the S3′ site of renin. An unexpected π-π stacking interaction was observed during docking study for compound 9r, which could be a reasonable explanation for the outstanding potency of this compound. Further study is in progress to reveal a feasibility for developing novel renin inhibitors based on the possible non-classical interactions between the ligands and the new subsite of renin.

Full text of DOI:10.1016/j.bmc.2011.05.059

Bioorganic & Medicinal Chemistry 19 (2011) 4238–4249
Contents lists available at ScienceDirect
Bioorganic & Medicinal Chemistry
journal homepage: www.elsevier.com/locate/bmc
Synthesis, biological evaluation and docking studies of octane-carboxamide
based renin inhibitors with extended segments toward S30 site of renin
Yong Wu a,b, Chen Shi a,b, Xiaowei Sun a,b, Xiaoming Wu a, , Hongbin Sun a,b,
⇑
⇑
a Center for Drug Discovery, College of Pharmacy, China Pharmaceutical University, 24 Tongjia Xiang, Nanjing 210009, China
b State Key Laboratory of Natural Medicines, China Pharmaceutical University, Nanjing 210009, China
a r t i c l e i n f o
a b s t r a c t
Eighteen octane-carboxamide based renin inhibitors with extended segments for mimicking P30 unit of
angiotensinogen have been synthesized. The biological evaluation identified novel renin inhibitors with
more potent activity than aliskiren. Molecular docking studies showed that the extended amide-tails
matched the P30 position of angiotensinogen and exerted interactions with the S30 site of renin. An unex-
Article history:
Received 23 March 2011
Revised 26 May 2011
Accepted 27 May 2011
Available online 1 June 2011
pected p–p stacking interaction was observed during docking study for compound 9r, which could be a
reasonable explanation for the outstanding potency of this compound. Further study is in progress to
reveal a feasibility for developing novel renin inhibitors based on the possible non-classical interactions
between the ligands and the new subsite of renin.
Keywords:
Renin inhibitors
Octane-carboxamide
S30 site
Ó 2011 Elsevier Ltd. All rights reserved.
Molecular docking
1. Introduction
MeO
OH
H
H2N
N
NH2
Renin, which initiates the generation of the potent vasoconstric-
tor angiotensin II (Ang II) by cleavaging of the Leu10-Val11 peptide
bond of angiotensinogen, is the first and rate-limiting step of
renin-angiotensinogen system (RAS). It has been recognized as a
promising drug target for hypertension control for decades.1,2 In
contrast to angiotensin-converting enzyme (ACE), renin exhibits
a remarkably high specificity since angiotensinogen is its only
known physiological substrate.1 That is to say, renin inhibition will
not cause undesirable side effects resulting from interference on
side metabolic pathways. Given the high specificity and upstream
position of renin in the RAS cascade, inhibition of renin is thought
to achieve more complete renin-angiotensin system blockade.3
Early renin inhibitors were designed based on peptidic or pepti-
domimetic scaffold which suffered from low stability and poor oral
bioavailability in human.4 None of the first-generation peptidic
renin inhibitors successfully went through clinical testing due to
short duration of action and weak blood-pressure-lowering activ-
ity. By means of molecular modeling and X-ray crystal structure
determination, new generation of non-peptidic renin inhibitors
were identified, and significant improvement in pharmacokinetic
and pharmacodynamic profiles has been achieved.1 Aliskiren was
identified as a transition-state mimetic non-peptide renin inhibitor
(Fig. 1), and was approved by FDA as the first antihypertensive drug
O
O
O
MeO
Figure 1. Structure of aliskiren.
from the renin inhibitor category.5 Aliskiren shows dose-dependent
oral activity, long durations of antihypertensive action and end
organ protective effects in experimental and clinical studies.6–8
Systematic investigations on structural modifications of classical
dipeptide transition state mimics (TSMs) renin inhibitors have been
carried out in the past decade.9–12 On the other hand, a number of
renin inhibitors with new chemotypes have also been identified
recently,13 and a few compounds have entered clinical trials.
There are eight amino acids located left and right of the Leu10
-
Val11 cleavage site of angiotensinogen, which binds to subsites of
human renin. The corresponding positions of the octapeptide se-
quence are positions P5 to P30.14 Intense studies have been per-
formed in the area between P4 and P20 to identify non-peptide
renin inhibitors, indicating that the P3, P1, P10 and P20 positions
are critical for binding.9,10 On the other hand, there are few studies
concerning the impact of the P30 position binding to renin.15 Here-
in, we describe synthesis and biological evaluation of a series of no-
vel aliskiren analogues which possess extended segments to
mimick P30 position binding to renin. The terminal amide of aliski-
ren plays as an anchor that tack the amide tail of aliskiren in S20
⇑
Corresponding authors. Tel.: +86 025 83271555 (X.W.); tel./fax: +86 025
83271198 (H.S.).
E-mail addresses: xmwu@cpu.edu.cn (X. Wu), hbsun2000@yahoo.com (H. Sun).
0968-0896/$ - see front matter Ó 2011 Elsevier Ltd. All rights reserved.
doi:10.1016/j.bmc.2011.05.059

Y. Wu et al. / Bioorg. Med. Chem. 19 (2011) 4238–4249
4239
Amines 7a–r were prepared from neopentyl glycol according to
the synthetic route depicted in Scheme 2. 1,3-Dibromo-2,2-
dimethylpropane (2) was obtained by reaction of neopentyl glycol
with triphenylphosphine and bromine in acetonitrile.17 Alkylation
of 2 with potassium phthalimide yielded 2-(3-bromo-2,2-dimeth-
ylpropyl) isoindoline-1,3-dione (3). Azidation of 3 with NaN3 in
DMF gave azide 4. Dephthaloylation of 4 in the present of 85%
hydrazine hydrate afforded amine 5. Derivatization of 5 by acid
anhydride, acyl halide, sulfonyl halide or sulfamide gave the corre-
sponding azide compounds 6a–p. Hydrogenative reduction of 6a–p
furnished amine compounds 7a–p. ‘Click’ chemical reaction of 5
O
O
O
O
O
H2N
R
N3
5, 7a-p or 7r
1
a
OH
H
O
O
N
R
18
N3
8a-r
O
with acetylene in the presence of CuSO4 provided triazole 7r.
O
2.2. Renin inhibitory activity and SAR analysis
b
Eighteen aliskiren analogues (9a–r) and aliskiren were tested in
renin fluorimetric assay19 with ‘SensoLyte™ 390 Renin Assay Kit’ at
six different concentrations from 500 to 0.16 nM. The assay result
(Tables 1) showed that most of the test compounds exhibited
potent inhibitory activity against renin, with IC50 values ranging
between 0.2 and 5 nM. Incorporation of sulfonamide group (for
9n: IC50 = 0.91 nM), dimethylurea group (for 9o: IC50 = 0.36 nM),
aminosulfamide group (for 9p: IC50 = 0.79 nM), and triazole group
(for 9r: IC50 = 0.2 nM) into the carboxamide moiety of aliskiren re-
sulted in significant increases in potency. It seems that the intro-
duction of hydrophilicity into this moiety is beneficial for renin
inhibitory activity. Compounds with short hydrophobic chains
(e.g., 9a, 9b and 9f) had relatively weak inhibitory activity, while
compounds with large hydrophobic groups (e.g., 9d, 9e, 9g, 9h, 9j
and 9l) showed relatively high potency in comparison with
aliskiren. Within this series of compounds, triazole 9r was the
most potent one that was 10-fold more potent than aliskiren
(IC50 = 2.21 nM).
OH
H
N
O
O
O
R
NH2
9a-r
O
Scheme 1. Reagents and conditions: (a) 2-hydroxypyridine, TEA, 65 °C, 5–8 h; (b)
H2, Pd/C, tert-butyl methyl ether, ethanolamine, 25 °C, 0.5–1 h.
position, forming hydrogen bond with Arg74.5 We designed inhib-
itors containing amide bioisosteres at the position of terminal
amide, which act as alternative anchors fixing the tail at the S20
position, and may lead the extended moieties to S30 site. Moreover,
molecular docking studies have been performed to confirm the
binding mode of the test compounds.
2. Results and discussion
2.1. Chemistry
2.3. Docking study
Aliskiren was docked with renin to confirm the effectiveness of
the docking method20 that we used in this study. The docking runs
were performed applying the genetic algorithm of GOLD Renin
structure used as receptor in docking was obtained from the pro-
tein data bank (PDB code: 2v0z). The docking conformation was
compared with that of aliskiren from crystallographic determina-
tion, resulting in an RMSD value of 0.7597 Å. This result demon-
strated that GOLD program could successfully make prediction of
The synthesis of compounds 9a–r is outlined in Scheme 1. Ring-
opening of lactone 1, which was readily prepared following the
literature procedures,16 with amines 5 or 7a–r in the presence of
2-hydroxypyridine afforded octanamides 8a–r. Hydrogenative
reduction of 8a–r in the presence of Pd/C provided the target
compounds 9a–r.
O
O
c
a
b
HO
OH
Br
Br
N
Br
N
N3
Neopentyl glycol
2
4
NH2
g
3
O
O
d
e
f
H2N
NHR1
N3
N3
NHR1
Cl
7a-p
6a-p
5
N
N
N
H2N
7r
Scheme 2. Synthesis of the amino compounds 7a–r. Reagents and conditions: (a) PPh3, Br2, CH3CN, 80 °C, 10 h, 65%; (b) potassium phthalimide, DMF, 10 h, 90 °C, 63%; (c)
NaN3, DMF, 8 h, 100 °C, 93%; (d) (i) 85% hydrazine hydrate, ethanol, 80 °C, 4 h; (ii) hydrogen chloride, 93%; (e) acid anhydride/acyl halide/sulfonyl halide, TEA, CH2Cl2, 8–12 h,
47–83%, or sulfonamide, dioxane, 105 °C, 15 h, 85%; (f) H2, 10% Pd/C, 15–20 min, 80–97%; (g) acetylene, CuSO4ꢀ5H2O, TEA, CH2Cl2, 8–12 h, 84.4%.

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Y. Wu et al. / Bioorg. Med. Chem. 19 (2011) 4238–4249
Table 1
Table 1 (continued)
Renin inhibitory activity of aliskiren and compounds 9a–r
a
ID
R
IC50
OH
H
N
N
N
R
O
O
O
N
Aliskirenb
2.21
NH2
O
a
The IC50 values were measured via renin fluorimetric assay.
Aliskiren was used as a positive control.
b
9a-r
a
ID
R
IC50
H
N
the mode of aliskiren binding to human renin. The overlay of dock-
ing conformation and crystallographic conformation of alikiren is
depicted in Figure 2.
9a
2.17
4.85
O
F
There has been no direct unequivocal definition of S30 site, just
prediction based on the crystallographic determination of recom-
binant human renin.21 The residues Glu134, Val198, Glu200,
Leu222, Asp300, Pro302, Pro307, Thr308 were thought to form
the S30 pocket (the numbering according to 2v0z) before. Since
H
N
F
F
9b
O
O
O
O
H
N
9c
9d
9e
1.08
1.12
1.48
H
N
H
N
H
N
9f
4.13
0.83
O
O
H
N
9g
H
N
O
S
9h
9i
1.15
0.81
1.02
Figure 2. Overlay of binding conformations of aliskiren from docking (colored by
atom: carbons: black; oxygens: red; nitrogens: blue; hydrogens: gray) and
crystallographic determination (showed in pure color of green) (RMSD 0.7597 Å).
O
H
N
O
O
H
N
9j
O
O
H
N
9k
9l
3.84
1.64
O
O
H
N
H
N
O
S
9m
9n
9o
9p
4.23
0.91
0.36
0.79
O
O
S
H
N
O
H
N
N
O
O
H
N
Figure 3. Redefinition of the S30 pocket directly based on crystal structure of
human angiotensinogen (colored by atom: carbons: purple; oxygens: red; nitro-
gens: blue; hydrogens: gray) (His13 in the P30 position: carbons in green)
complexed with human renin (PDB code: 2x0b). The residues (colored by atom:
carbons: yellow; oxygens: red; nitrogens: blue) Leu73, Arg74, Tyr75, Ser76, Ile291,
Pro292, Pro293, Pro294 were defined as S30 pocket (the numbering according to
2v0z).
NH2
S
O
9q
9r
–NH2
2.88
0.2

Y. Wu et al. / Bioorg. Med. Chem. 19 (2011) 4238–4249
4241
crystal structure of human angiotensinogen complexed with renin
(PDB code: 2x0b) was available recently,22 we tried to redefine the
S30 pocket directly based on the structure of receptor–ligand com-
plex (see Fig. 3).
Compound 9d was docked into the binding site of renin to seek
the binding mode of the extended amide-tail derivatives with renin.
The result showed that 9d was nicely bound to the five aliskiren-
binding site pockets on renin (S3sp, S3, S1, S10, S20), and its binding
conformation was stabilized by seven hydrogen bonds with Try 14
(bond length: Try 14 N–Hꢀ ꢀ ꢀO = 3.067 Å; bond angle: Try 14
N–Hꢀ ꢀ ꢀO = 134.9°), Asp 32 (with 5-NH2, bond length: Asp
32 = Oꢀ ꢀ ꢀH–N 1.855 Å, bond angle: Asp 32 = Oꢀ ꢀ ꢀH–N 165.9°; with
4-OH, bond length: Asp 32 = Oꢀ ꢀ ꢀH–O 2.040 Å, bond angle: Asp
32 = Oꢀ ꢀ ꢀH–O 174.2°), Asp 215 (bond length: Asp 215 = Oꢀ ꢀ ꢀH–N
1.802 Å; bond angle: Asp 215 = Oꢀ ꢀ ꢀH–N 146.3°), Gly 34 (bond
length: Gly34 N–Hꢀ ꢀ ꢀO = 1.95 Å; bond angle: Gly34
N–Hꢀ ꢀ ꢀO = 172.0°), Ser 76 (bond length: Ser 76 N–Hꢀ ꢀ ꢀO = 2.425 Å;
bond angle: Ser 76 N–Hꢀ ꢀ ꢀO = 148.8°) and Arg 74 (bond length:
Arg 74 = Oꢀ ꢀ ꢀH–N 1.653 Å; bond angle: Arg 74 = Oꢀ ꢀ ꢀH–N 165.6°)
(see Fig. 4 for detailed locations of hydrogen bonds). The docked
binding conformation showed that the retro-amide bioisostere
Figure 6. Overlay of conformation of aliskiren from crystal structure (PDB code:
2v0z) (colored by atom: carbons: sky blue; oxygens: red; nitrogens: blue;
hydrogens: gray) and compound 9r (colored by atom: carbons: yellow; oxygens:
red; nitrogens: blue; hydrogens: gray) docked with human renin (PDB code: 2v0z).
The unusual binding mode of 9r: probable hydrogen bond with Gln 128 and
p–p
stacking interaction with Tyr 75 (showed as yellow dotted lines).
entirely anchors the tail at the S20 position, and the extended
amide-tail moiety of 9d stretched directly to our new defined S30
site pocket (see Figs. 4 and 5). Other compounds were also docked
with renin, and most of them were found to have the same binding
mode with 9d, except for compound 9r. The binding result of 9r
showed no hydrogen-bonding interaction with Arg 74. The terminal
1,2,3-triazole group stretched in an opposite direction from S30 site
pocket. The 5-H of 1,2,3-triazole ring formed a C–Hꢀ ꢀ ꢀO = hydrogen
bond with Gln 128 (bond length: Gln 128 = Oꢀ ꢀ ꢀH–C 2.517 Å; bond
angle: Gln 128 = Oꢀ ꢀ ꢀH–C 173.3°). A probable
p–p stacking interac-
tion (center distance: 4.67; closest atom distance: 4.5; lambda
angle: 30°; theta angle: 60°) was also found between the aromatic
1,2,3-triazole ring and benzene ring of Tyr 75 (see Fig. 6). This
unique binding mode of 9r could be a reasonable explanation for
the particularly high potency of this compound.
3. Conclusions
Figure 4. Overlay of conformation of aliskiren from crystal structure (PDB code:
2v0z) (colored by atom: carbons: sky blue; oxygens: red; nitrogens: blue;
hydrogens: gray) and compound 9d (colored by atom: carbons: green; oxygens:
red; nitrogens: blue; hydrogens: gray) docked with human renin (PDB code: 2v0z).
The binding conformation of 9d and seven hydrogen bonds (showed as yellow
dotted lines) with corresponding amino acid residues (colored by atom: carbons:
pink; oxygens: red; nitrogens: blue; hydrogens: gray).
A series of renin inhibitors with extended amide-tail based on
aliskiren have been synthesized and biologically evaluated. Most
of the synthesized aliskiren analogues showed higher potency than
aliskrien. SAR analysis showed that introduction of hydrophilicity
into the amide-tail moiety of aliskiren resulted in significant in-
creases in potency. Compound 9r was the most potent one among
this series of compounds, and was 10-fold more potent than aliski-
ren. We redefined the S30 site based on the recently published crys-
tal structure data, and molecular docking was performed to
disclose the binding mode of these renin inhibitors. Analysis of
the binding conformation of 9d with renin revealed that the ex-
tended segments at the amide-tail did stretch to the S30 site pocket
of renin, and mimicked the P30 site of angiotensinogen binding to
renin. An unexpected
p–p stacking interaction was also observed
in docking study on 9r with renin. It could be one of the contribu-
tors for the outstanding potency of this compound. Further study is
in progress to reveal a feasibility for developing novel renin inhib-
itors based on the possible non-classical interactions between the
ligands and the new subsite of renin.
4. Experimental
SensoLyte™ 390 Renin Assay Kit(Fluorimetric) was purchased
from AnaSpec, Inc. Other reagents were purchased from commer-
cial suppliers and were dried and purified when necessary.
Figure 5. The extended segment of 9d (colored by atom: carbons: green; oxygens:
red; nitrogens: blue; hydrogens: gray) binding with S30 site pocket (residues Leu73,
Arg74, Tyr75, Ser76, Ile291, Pro292, Pro293 and Pro294).

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Y. Wu et al. / Bioorg. Med. Chem. 19 (2011) 4238–4249
Fluorescence intensity was measured with EnVision 2104 Multila-
bel Reader (PerkinElmer). 1H and 13C NMR spectra were recorded
using both Bruker AVANCE-300 (300 MHz) and Bruker AVANCE-
500 (500 MHz). Low-resolution mass spectra (MS) and High-
resolution mass spectra (HRMS) were obtained using Waters
MicroMass Q-Tof (ESI). Optical rotation data were recorded on
Jasco p-1020 Polarimeter. Melting Points were checked with
Tianfen RY-1 Melting Point Apparatus.
(2 ꢁ 15 mL). The combined organic phase was washed with water
and brine, dried (Na2SO4) and concentrated. The title compound
was obtained from the residue by means of flash chromatography.
4.2.1. N-(3-Azido-2,2-dimethylpropyl)acetamide (6a)
Starting with 5 (164 mg, 1 mmol) and acetic anhydride (110 lL,
1.2 mmol), 6a (110 mg, 65%) was obtained as a colorless oil after
purification by flash chromatography (hexane:EtOAc, 8:1): 1H
NMR (300 MHz, CDCl3) d 0.95 (s, 6H), 2.04 (s, 3H), 3.15–3.19 (m,
4H), 6.04 (br, 1H); 13C NMR (75 MHz, CDCl3) d 23.2, 23.3, 23.9,
36.3, 47.4, 60.8, 170.3; MS(ESI) m/z 193.2 [M+Na]+.
4.1. Chemistry
4.1.1. 1,3-Dibromo-2,2-dimethylpropane (2)
To a solution of triphenylphosphine (26.2 g, 0.1 mol) in acetoni-
trile (50 mL) was added dropwise a solution of liquid bromine
(5.13 ml, 0.1 mol) in acetonitrile (30 mL) at 0 °C, then neopentyl
glycol (5.2 g, 0.05 mol) was added. The reaction mixture was
heated to 80 °C, and refluxed for 10 h. The solvent was removed
under vacuum, light yellow oil 2 (7.5 g, 65%) was obtained by vac-
uum distillation. 1H NMR (300 MHz, CDCl3) d 1.17 (s, 6H), 3.41 (s,
2H), 3.47 (s, 2H).
4.2.2. N-(3-Azido-2,2-dimethylpropyl)-2,2,2-trifluoroacetamide
(6b)
Starting with
5 (100 mg, 0.6 mmol) and trifluoroacetic
anhydride (100 L, 0.72 mmol), 6b (66 mg, 49%) was obtained as
l
a
colorless oil after purification by flash chromatography
(hexane:EtOAc, 20:1): 1H NMR (300 MHz, CDCl3) d 0.99 (s, 6H),
3.35–3.28(m, 4H), 6.69(br, 1H); 13C NMR (75 MHz, CDCl3) d 23.3,
36.0, 48.0, 61.0, 114.0, 134.1; MS(ESI) m/z 247.1 [M+Na]+.
4.1.2. 2-(3-Bromo-2,2-dimethylpropyl)isoindoline-1,3-dione (3)
A solution of 2 (1.0 g, 4.4 mmol), potassium phthalimide (0.4 g,
2.2 mmol) in DMF (10 mL) was stirred at 90 °C for 10 h. The mix-
ture was poured into H2O (30 mL) and the suspension was ex-
tracted with EtOAc (2 ꢁ 30 mL). The combined organic layers
were dried (Na2SO4) and concentrated under reduced pressure.
Purification of the residue by flash chromatography
(hexane:EtOAc, 20:1) gave 3 (0.41 g, 63%) as a white solid: mp
75–76.5 °C; 1H NMR (300 MHz, CDCl3) d 1.11 (s, 6H), 3.38 (s, 2H),
3.70 (s, 2H), 7.72–7.88 (m, 4H); 13C NMR (75 MHz, CDCl3) d 24.6,
37.6, 44.5, 46.2, 123.3, 131.9, 134.1, 168.7; MS (ESI) m/z 318.0
[M+Na]+.
4.2.3. N-(3-Azido-2,2-dimethylpropyl)propionamide (6c)
Starting with 5 (164 mg, 1 mmol) and propionic andydride
(156 lL, 1.2 mmol), 6c (151 mg, 82%) was obtained as a colorless
oil after purification by flash chromatography (hexane:EtOAc,
8:1): 1H NMR (300 MHz, CDCl3) d 0.90 (s, 6H), 1.17 (t, J = 7.7 Hz,
3H), 2.23 (q, J = 15.2, 7.6 Hz, 2H), 3.16 (s, 1H), 3.18 (s, 3H), 5.71
(br, 1H); 13C NMR (75 MHz, CDCl3) d 10.0, 23.2, 29.9, 36.4, 47.3,
60.9, 174.0; MS(ESI) m/z 185.1 [M+H]+.
4.2.4. N-(3-Azido-2,2-dimethylpropyl)butyramide (6d)
Starting with 5 (164 mg, 1 mmol) and propionic andydride
(154 lL, 1.2 mmol), 6d (120 mg, 65%) was obtained as a colorless
oil after purification by flash chromatography (hexane:EtOAc,
8:1): 1H NMR (300 MHz, CDCl3) d 0.89–0.99 (m, 9H), 1.70 (m,
2H), 2.19 (t, J = 7.3 Hz, 2H), 3.13–3.24 (m, 4H), 5.69 (br, 1H); 13C
NMR (75 MHz, CDCl3) d 13.8, 19.2, 23.3, 36.4, 38.9, 47.2, 60.9,
173.1; MS(ESI) m/z 199.1 [M+H]+.
4.1.3. 2-(3-Azido-2,2-dimethylpropyl)isoindoline-1,3-dione (4)
A mixture of 3 (0.48 g, 1.6 mmol) and NaN3 (0.13 g, 1.9 mmol)
in DMF (2 mL) was stirred at 100 °C for 8 h. The reaction mixture
was poured into H2O (10 mL) and the suspension was extracted
with EtOAc (2 ꢁ 10 mL). The combined organic layers were dried
(Na2SO4) and concentrated under reduced pressure. Purification
of the residue by flash chromatography (hexane:EtOAc, 20:1) gave
4 (0.39 g, 93%) as a white solid: mp 61–62 °C; 1H NMR (300 MHz,
CDCl3) d 1.01 (s, 6H), 3.24 (s, 2H), 3.59 (s, 2H), 7.72–7.88 (m,
4H); 13C NMR (75 MHz, CDCl3) d 23.7, 38.0, 45.7, 60.8, 123.3,
131.9, 134.1, 168.9; MS (ESI) m/z 281.1 [M+Na]+.
4.2.5. N-(3-Azido-2,2-dimethylpropyl)-3-methylbutanamide
(6e)
Starting with 5 (164 mg, 1 mmol) and isoveryl chloride (146 lL,
1.2 mmol), 6e (145 mg, 68.3%) was obtained as a white solid after
purification by flash chromatography (hexane:EtOAc, 5:1): mp
43–44 °C; 1H NMR (300 MHz, CDCl3)
d 0.95–0.98 (m, 12H),
2.05–2.17 (m, 2H), 3.16–3.18 (m, 4H), 5.69 (br, 1H); 13C NMR
(75 MHz, CDCl3) d 22.5, 23.3, 26.1, 36.4, 46.3, 47.2, 60.9, 172.6;
MS(ESI) m/z 235.1 [M+Na]+.
4.1.4. 3-Azido-2,2-dimethylpropan-1-amine (5)
To a solution of 4 (2.6 g, 10 mmol) in ethanol (40 mL) was added
85% hydrazine hydrate (3.12 mL, 50 mmol), and the resulting mix-
ture was stirred at 80 °C for 4 h. The mixture was cooled to room
temperature, and the insoluble solids were filtered. The filtrate
was poured into H2O (40 mL), extracted with ethyl ether
(2 ꢁ 40 mL). The combined organic layer was dried (Na2SO4), and
then treated with hydrogen chloride. The solution was concen-
trated under reduced pressure to afford 5 (1.83 g, 93%) as a light
yellow solid: mp 86–89 °C; 1H NMR (300 MHz, DMSO-d6) d 0.96
(s, 6H), 2.66 (s, 2H), 3.48 (s, 2H), 8.25 (br, 3H); 13C NMR (75 MHz,
DMSO-d6) d 22.5, 34.5, 45.8, 58.3; MS (ESI) m/z 129.1 [M+H]+.
4.2.6. N-(3-Azido-2,2-dimethylpropyl)pivalamide (6f)
Starting with 5 (164 mg, 1 mmol) and pivalyl chloride (147 lL,
1.2 mmol), 6f (170 mg, 80.1%) was obtained as a colorless oil after
purification by flash chromatography (hexane:EtOAc, 5:1): 1H NMR
(300 MHz, CDCl3) d 0.86 (s, 9H), 1.20 (s, 9H), 2.56 (s, 2H), 2.70 (br,
1H), 3.13–3.18 (m, 2H), 5.99 (br, 1H); 13C NMR (75 MHz, CDCl3) d
23.9, 27.6, 35.0, 38.7, 48.4, 51.1, 61.2, 178.8; MS(ESI) m/z 235.1
[M+Na]+.
4.2.7. N-(3-Azido-2,2-dimethylpropyl)hexanamide (6g)
4.2. General procedure for the preparation of 6a–o
Starting with 5 (164 mg, 1 mmol) and n-caproic anhydride
(277 lL, 1.2 mmol), 6g (180 mg, 79.5%) was obtained as a colorless
To a solution of 0.6–1.5 mmol of 5, triethylamine (2.4 equiv) in
CH2Cl2 (5 mL) was added slowly acid anhydride (1–1.2 equiv), acyl
halide (1–1.2 equiv), or sulfonyl halide (1–1.2 equiv) at 0 °C. The
reaction mixture was stirred at 25 °C for 8–12 h. The reaction
was quenched with water (15 mL) and extracted with ethyl acetate
oil after purification by flash chromatography (hexane:EtOAc, 5:1):
1H NMR (300 MHz, CDCl3) d 0.88–0.94 (m, 9H), 1.32–1.34 (m, 4H),
1.64 (br, 2H), 2.19 (t, J = 7.4 Hz, 2H), 3.15–3.18 (m, 4H), 5.69 (br,
1H); 13C NMR (75 MHz, CDCl3) d 13.9, 22.4, 23.3, 25.5, 31.5, 36.9,
47.2, 60.1, 173.3; MS(ESI) m/z 249.2 [M+Na]+.

Y. Wu et al. / Bioorg. Med. Chem. 19 (2011) 4238–4249
4243
4.2.8. N-(3-Azido-2,2-dimethylpropyl)-4-methylbenzene
sulfonamide (6h)
(br, 1H); 13C NMR (75 MHz, CDCl3) d 8.20, 23.1, 35.9, 46.6, 50.7,
59.7; MS(ESI) m/z 243.1 [M+Na]+.
Starting with 5 (200 mg, 1.2 mmol) and p-toluenesulfonyl chlo-
ride (232 mg, 1.2 mmol), 6h (280 mg, 83.3%) was obtained as a
white solid after purification by flash chromatography (hex-
ane:EtOAc, 5:1): mp 79–81 °C; 1H NMR (300 MHz, CDCl3) d 0.91
(s, 6H), 2.43 (s, 3H), 2.56 (s, 2H), 2.70 (br, 1H), 3.13–3.18 (m, 2H),
7.26–7.75 (m, 4H); 13C NMR (75 MHz, CDCl3) d 21.5, 23.6, 34.2,
51.8, 53.1, 59.8, 127.0, 129.7, 137.2, 142.9; MS(ESI) m/z 257.0
[M+H]+.
4.2.15. 3-(3-Azido-2,2-dimethylpropyl)-1,1-dimethylurea (6o)
Starting with 5 (164 mg, 1 mmol) and N,N-dimethylcarbamoyl
chloride (90 lL, 1 mmol), 6o (95 mg, 47.7%) was obtained as a col-
orless oil after purification by flash chromatography (hex-
ane:EtOAc, 4:1); 1H NMR (300 MHz, CDCl3) d 0.94 (s, 6H), 2.92 (s,
6H), 3.15 (d, J = 6.2 Hz, 2H), 3.19 (s, 2H), 4.67 (br, 1H); 13C NMR
(75 MHz, CDCl3) d 23.2, 36.2, 49.0, 61.1, 158.5; MS(ESI) m/z 222.1
[M+Na]+.
4.2.9. Ethyl (3-azido-2,2-dimethylpropyl)carbamate (6i)
Starting with 5 (200 mg, 1.2 mmol) and ethyl chlorocarbonate
(116 lL, 1.2 mmol), 6i (180 mg, 75%) was obtained as a colorless
oil after purification by flash chromatography (hexane:EtOAc,
5:1): 1H NMR (300 MHz, CDCl3) d 0.91 (s, 6H), 2.43 (s, 3H), 2.56
(s, 2H), 2.70 (br, 1H), 3.13–3.18 (m, 2H), 7.26–7.75 (m, 4H); 13C
NMR (75 MHz, CDCl3) d 21.5, 23.6, 34.2, 51.8, 53.1, 59.8, 127.0,
129.7, 137.2, 142.9; MS(ESI) m/z 257.0 [M+H]+.
4.2.16. N-(3-Azido-2,2-dimethylpropyl)aminosulfamide (6p)
Compound 5 (200 mg, 1.2 mmol) was dissolved in ethyl ether
(5 mL) and was neutralized by 0.5 N NaOH. The solution was con-
centrated carefully under reduced pressure. The residue was dis-
solved in dioxane (10 mL), and then sulfonamide (900 mg,
5.2 mmol) was added. The resulting mixture was heated to
105 °C, and refluxed for 15 h. The mixture was poured into H2O
(30 mL) and extracted with EtOAc (2 ꢁ 30 mL). The combined or-
ganic layer was dried (Na2SO4) and concentrated under reduced
pressure. Purification of the residue by flash chromatography (hex-
ane:EtOAc, 4:1) gave 6p (210 g, 85%) as a light yellow solid: mp
69–71 °C; 1H NMR (300 MHz, CDCl3) d 0.98 (s, 6H), 2.97 (d,
J = 7.1 Hz, 2H), 3.23 (s, 2H), 4.76 (m, 3H); 13C NMR (75 MHz, CDCl3)
d 23.2, 35.7, 51.1, 59.9; MS(ESI) m/z 206.1 [MꢂH]ꢂ.
4.2.10. N-(3-Azido-2,2-dimethylpropyl)benzamide (6j)
Starting with 5 (164 mg, 1 mmol) and benzoyl chloride (130 lL,
1.1 mmol), 6j (160 mg, 69%) was obtained as a white solid after
purification by flash chromatography (hexane:EtOAc, 5:1): mp
52–54 °C; 1H NMR (300 MHz, CDCl3) d 1.07 (s, 6H), 3.27 (s, 2H),
3.38 (d, J = 6.3 Hz, 2H), 6.47 (br, 1H), 7.42–7.78 (m, 5H); 13C NMR
(75 MHz, CDCl3) d 23.4, 36.5, 48.0, 61.2, 126.8, 128.6, 131.5,
134.6, 167.6; MS(ESI) m/z 255.1 [M+Na]+.
4.3. General procedure for the preparation of 7a–p
4.2.11. N-(3-Azido-2,2-dimethylpropyl)-4-methoxybenzamide
(6k)
Starting with 5 (164 mg, 1 mmol) and 4-methoxybenzoyl chlo-
ride (140 lL, 1 mmol), 6k (165 mg, 63%) was obtained as a white
solid after purification by flash chromatography (hexane:EtOAc,
5:1): mp 88–90 °C; 1H NMR (300 MHz, CDCl3) d 1.00 (s, 6H), 3.25
(s, 2H), 3.35 (d, J = 6.4 Hz, 2H), 3.84 (s, 3H), 6.39 (br, 1H), 6.92 (d,
J = 8.8 Hz, 2H), 7.74 (d, J = 8.6 Hz, 2H); 13C NMR (75 MHz, CDCl3)
d 23.4, 36.6, 47.9, 55.3, 61.2, 113.8, 126.9, 128.6, 162.2, 167.1;
MS(ESI) m/z 263.2 [M+H]+.
A solution of 6a–p (0.15–0.75 mmol) in methanol (5–10 mL)
was hydrogenated in the presence of 20 mg of 10% Pd/C (moist)
at 25 °C over 15–20 min. The reaction mixture was filtered and
the solids were washed with methanol. The filtrate was concen-
trated under reduced pressure to give the amine products.
4.3.1. N-(3-Amino-2,2-dimethylpropyl)acetamide (7a)
Starting with 6a (60 mg, 0.35 mmol), 7a (45 mg, 90%) was ob-
tained as a colorless oil: 1H NMR (300 MHz, CDCl3) d 0.89 (s, 6H),
1.52 (br, 1H), 1.98 (s, 3H), 2.54 (s, 2H), 3.15 (d, J = 5.8 Hz, 2H),
6.92 (br, 1H); 13C NMR (75 MHz, CDCl3) d 23.3, 23.5, 34.8, 48.6,
51.4, 170.1; MS(ESI) m/z 145.1 [M+H]+.
4.2.12. N-(3-Azido-2,2-dimethylpropyl)-2-phenylacetamide (6l)
Starting with 5 (164 mg, 1 mmol) and phenylacetyl chloride
(160 lL, 1.2 mmol), 6l (161 mg, 65%) was obtained as a colorless
4.3.2. N-(3-Amino-2,2-dimethylpropyl)-2,2,2-trifluoroacet-
amide (7b)
oil after purification by flash chromatography (hexane:EtOAc,
5:1): 1H NMR (300 MHz, CDCl3) d 0.83 (s, 6H), 3.03 (s, 2H), 3.10
(d, J = 6.2 Hz, 2H), 3.60 (s, 2H), 5.68 (br, 1H), 7.26–7.40 (m, 5H);
13C NMR (75 MHz, CDCl3) d 23.1, 36.1, 44.0, 47.6, 61.0, 127.5,
129.0, 129.4, 134.9, 171.1; MS(ESI) m/z 269.1 [M+Na]+.
Starting with 6b (32 mg, 0.14 mmol), 7b (27 mg, 94%) was ob-
tained as a white solid: mp 86–88 °C; 1H NMR (300 MHz, CDCl3)
d 0.95 (s, 6H), 1.67 (br, 2H), 2.73 (s, 2H), 3.28 (s, 2H), 9.73 (br,
1H); 13C NMR (75 MHz, CDCl3) d 23.4, 33.6, 51.0, 52.5, 118.1,
156.9; MS(ESI) m/z 199.0 [M+H]+.
4.2.13. N-(3-Azido-2,2-dimethylpropyl)methanesulfonamide
(6m)
4.3.3. N-(3-Amino-2,2-dimethylpropyl)propionamide (7c)
Starting with 6c (100 mg, 0.54 mmol), 7c (80 mg, 94%) was ob-
tained as a colorless oil: 1H NMR (300 MHz, CDCl3) d 0.89 (s, 6H),
1.52 (br, 1H), 1.98 (s, 3H), 2.54 (s, 2H), 3.15 (d, J = 5.8 Hz, 2H),
6.92 (br, 1H); 13C NMR (75 MHz, CDCl3) d 23.3, 23.5, 34.8, 48.6,
51.4, 170.1; MS(ESI) m/z 159.1 [M+H]+.
Starting with 5 (250 mg, 1.5 mmol) and methylsulfonyl chloride
(201 mg, 1.75 mmol), 6m (206 mg, 67%) was obtained as a light
yellow solid after purification by flash chromatography (hex-
ane:EtOAc, 5:1): mp 45–46 °C; 1H NMR (300 MHz, CDCl3) d 0.99
(s, 6H), 2.97 (s, 3H), 2.98 (d, J = 6.2 Hz, 2H), 3.20 (s, 2H), 4.74 (br,
1H); 13C NMR (75 MHz, CDCl3) d 23.1, 35.8, 40.0, 45.7, 50.8; MS(E-
SI) m/z 205.1 [MꢂH]ꢂ.
4.3.4. N-(3-Amino-2,2-dimethylpropyl)butyramide (7d)
Starting with 6d (80 mg, 0.40 mmol), 7d (60 mg, 87%) was ob-
tained as a white solid: mp 105–109 °C; 1H NMR (300 MHz, CDCl3)
d 0.88 (s, 6H), 0.95 (t, J = 7.3 Hz, 3H), 1.65 (m, 2H), 1.67 (br, 2H),
2.16 (t, J = 7.3 Hz, 2H), 2.53 (s, 2H), 3.15 (d, J = 5.9 Hz, 2H), 6.83
(br, 1H); 13C NMR (75 MHz, CDCl3) d 13.8, 19.3, 23.5, 38.9, 48.3,
51.4, 173.1; MS(ESI) m/z 173.1 [M+H]+.
4.2.14. N-(3-Azido-2,2-dimethylpropyl)ethanesulfonamide (6n)
Starting with 5 (200 mg, 1.2 mmol) and ethanesulfonyl chloride
(115 lL, 1.2 mmol), 6n (104 mg, 47.3%) was obtained as a white so-
lid after purification by flash chromatography (hexane:EtOAc, 5:1):
1H NMR (300 MHz, CDCl3) d 0.98 (s, 6H), 1.37 (t, J = 7.4 Hz, 3H),
2.95 (d, J = 6.9 Hz, 2H), 3.05 (q, J = 7.4 Hz, 2H), 3.24 (s, 2H), 4.86

4244
Y. Wu et al. / Bioorg. Med. Chem. 19 (2011) 4238–4249
4.3.5. N-(3-Amino-2,2-dimethylpropyl)-3-methylbutanamide
(7e)
4.3.13. N-(3-Amino-2,2-dimethylpropyl)methanesulfonamide
(7m)
Starting with 6e (80 mg, 0.40 mmol),7e (65 mg, 95%) was ob-
tained as a colorless oi: 1H NMR (300 MHz, CDCl3) d 0.88 (s, 6H),
0.96 (d, J = 6.2 Hz, 6H), 1.90 (br, 2H), 2.03–2.14 (m, 3H), 2.54 (s,
2H), 3.16 (d, J = 5.8 Hz, 2H), 6.80 (br, 1H); 13C NMR (75 MHz, CDCl3)
d 22.5, 23.6, 26.1, 35.0, 46.4, 48.2, 51.3, 172.6; MS(ESI) m/z 187.1
[M+H]+.
Starting with 6m (100 mg, 0.49 mmol), 7m (70 mg, 80%) was
obtained as a colorless oil: 1H NMR (300 MHz, CDCl3) d 0.95 (s,
6H), 2.64 (s, 2H), 2.93 (s, 3H), 3.01 (s, 2H), 3.01–3.40 (br, 2H); 13C
NMR (75 MHz, CDCl3) d 23.7, 34.4, 39.7, 51.6, 52.9; MS(ESI) m/z
181.1 [M+H]+.
4.3.14. N-(3-Amino-2,2-dimethylpropyl)ethanesulfonamide
(7n)
4.3.6. N-(3-Amino-2,2-dimethylpropyl)pivalamide (7f)
Starting with 6f (96 mg, 0.45 mmol), 7f (78 mg, 92%) was ob-
tained as a colorless oil: 1H NMR (300 MHz, CDCl3) d 0.94 (s, 6H),
1.21 (s, 9H), 3.15–3.18 (m, 4H), 5.95 (br, 1H); 13C NMR (75 MHz,
CDCl3) d 22.3, 27.6, 36.4, 38.8, 47.4, 61.2, 178.5; MS(ESI) m/z
187.2 [M+H]+.
Starting with 6n (60 mg, 0.27 mmol), 7n (50 mg, 94%) was ob-
tained as a colorless oil: 1H NMR (300 MHz, CDCl3) d 0.95 (s, 6H),
1.36 (t, J = 7.4 Hz, 3H), 2.61 (s, 2H), 2.98–3.05 (m, 2H); 13C NMR
(75 MHz, CDCl3) d 8.3, 23.6, 34.4, 46.2, 52.0, 53.3; MS(ESI) m/z
195.1 [M+H]+.
4.3.15. 3-(3-Amino-2,2-dimethylpropyl)-1,1-dimethylurea (7o)
Starting with 6o (100 mg, 0.50 mmol), 7o (83 mg, 95%) was ob-
tained as a gray solid: mp 115–120 °C; 1H NMR (300 MHz, CDCl3) d
0.89 (s, 6H), 2.17 (br, 2H), 2.56 (s, 2H), 2.89 (s, 6H), 3.13 (d,
J = 5.3 Hz, 2H), 5.98 (br, 1H); 13C NMR (75 MHz, CDCl3) d 23.6,
34.9, 36.2, 50.1, 51.3, 158.9; MS(ESI) m/z 174.2 [M+H]+.
4.3.7. N-(3-Amino-2,2-dimethylpropyl)hexanamide (7g)
Starting with 6g (170 mg, 0.75 mmol), 7g (145 mg, 97%) was ob-
tained as a white solid: mp 95–96 °C; 1H NMR (300 MHz, CDCl3) d
0.88 (s, 9H), 1.30–1.34 (m, 4H), 1.65 (br, 2H), 2.18 (t, J = 7.4 Hz, 2H),
2.53 (s, 2H), 3.15 (d, J = 5.9 Hz, 2H), 6.85 (br, 1H); 13C NMR
(75 MHz, CDCl3) d 13.9, 22.4, 23.5, 25.6, 31.5, 35.0, 37.0, 48.3,
51.4, 173.3; MS(ESI) m/z 201.2 [M+H]+.
4.3.16. N-(3-Amino-2,2-dimethylpropyl)aminosulfamide (7p)
Starting with 6p (60 mg, 0.29 mmol), 7p (51 mg, 97%) was ob-
tained as a colorless oil: 1H NMR (300 MHz, CDCl3) d 0.95 (s, 6H),
2.65 (s, 2H), 3.02 (s, 2H), 7.57 (s, 1H), 3.00–4.00 (br, 2H); 13C
NMR (75 MHz, CDCl3) d 23.7, 34.2, 51.8, 53.4; MS(ESI) m/z 180.0
[MꢂH]ꢂ.
4.3.8. N-(3-Amino-2,2-dimethylpropyl)-4-methylbenzene-
sulfon-amide (7h)
Starting with 6h (100 mg, 0.35 mmol), 7h (66 mg, 80.5%) was
obtained as a colorless oil: 1H NMR (300 MHz, CDCl3) d 0.88 (s,
6H), 2.42 (s, 3H), 2.58 (s, 2H), 2.79 (s, 2H), 4.98 (br, 1H); 13C
NMR (75 MHz, CDCl3) d 22.3, 27.6, 36.4, 38.8, 47.4, 61.2, 178.5;
MS(ESI) m/z 235.1 [M+Na]+.
4.3.17. 2,2-Dimethyl-3-(1H-1,2,3-triazol-1-yl)propan-1-amine
(7r)
To a mixture of 5 (164 mg, 1 mmol), 1 N aqueous CuSO4ꢀ5H2O
(100 lL, 0.1 mmol) and Et3N (167 lL, 1.2 mmol) in CH2Cl2
4.3.9. Ethyl (3-amino-2,2-dimethylpropyl)carbamate (7i)
Starting with 6i (90 mg, 0.45 mmol), 7i (76 mg, 97%) was ob-
tained as a gray solid: mp 90–93 °C; 1H NMR (300 MHz, CDCl3) d
0.88 (s, 6H), 1.24 (t, J = 7.0 Hz, 3H), 1.95 (br, 2H), 2.52 (s, 2H),
3.06 (d, J = 6.1 Hz, 2H), 4.07–4.12 (m, 2H), 5.54 (br, 1H); 13C NMR
(75 MHz, CDCl3) d 14.6, 23.2, 35.5, 38.8, 49.2, 50.6, 60.7, 157.1;
MS(ESI) m/z 175.0 [M+H]+.
(10 mL) was introduced a stream of acetylene gas for 2 h. The mix-
ture was poured into H2O (20 mL) and extracted with ethyl ether
(2 ꢁ 20 mL). The combined organic layer was dried (Na2SO4) and
concentrated under reduced pressure to afford 7r (0.13 g, 84.4%)
as a colorless oil: 1H NMR (300 MHz, CDCl3) d 0.93 (s, 6H), 1.49
(br, 2H), 2.44 (s, 2H), 4.29 (s, 2H), 7.57 (s, 1H), 7.68 (s, 1H); 13C
NMR (75 MHz, CDCl3) d 23.5, 36.7, 49.4, 56.9, 124.8, 133.2; MS(ESI)
m/z 155.1 [M+H]+.
4.3.10. N-(3-Amino-2,2-dimethylpropyl)benzamide (7j)
Starting with 6j (60 mg, 0.26 mmol), 7j (50 mg, 94%) was ob-
tained as a colorless oil: 1H NMR (300 MHz, CDCl3) d 0.96 (s, 6H),
1.81 (br, 2H), 2.68 (s, 2H), 3.37 (d, J = 5.3 Hz, 2H), 7.38–7.82 (m,
5H), 8.42 (br, 1H); 13C NMR (75 MHz, CDCl3) d 23.8, 34.6, 50.1,
52.1, 126.9, 128.4, 131.1, 134.8, 167.3; MS(ESI) m/z 207.2 [M+H]+.
4.4. General procedure for the preparation of 8a–r
A mixture of 0.11 mmol of 1, 5/7a–p/7r (2–5 equiv), triethyl-
amine (10 equiv) and 2-hydroxypyridine (0.2 equiv) was stirred
at 65 °C over 5–8 h. The reaction mixture was cooled to room tem-
perature, concentrated under reduced pressure. To the residue was
added 1 M aqueous sodium hydrogen carbonate, and extracted
with ethyl acetate. The combined organic phase was washed with
water and brine, dried (Na2SO4) and concentrated to afford the
crude product.
4.3.11. N-(3-Amino-2,2-dimethylpropyl)-4-methoxybenzamide
(7k)
Starting with 6k (105 mg, 0.40 mmol), 7k (83 mg, 87.7%) was
obtained as a white solid: mp 74–76 °C; 1H NMR (300 MHz, CDCl3)
d 0.96 (s, 6H), 1.80 (br, 2H), 2.68 (s, 2H), 3.36 (d, J = 5.3 Hz, 2H), 3.83
(s, 3H), 6.90 (d, J = 8.6 Hz, 2H), 7.77 (d, J = 8.6 Hz, 2H), 8.25 (br, 1H);
13C NMR (75 MHz, CDCl3) d 23.8, 34.7, 50.0, 52.1, 55.3, 113.6, 127.2,
128.7, 161.9, 166.9; MS(ESI) m/z 237.2 [M+H]+.
4.4.1. (2S,4S,5S,7S)-5-Azido-N-(3-amino-2,2-dimethylpropyl)-
4-hydroxy-2-isopropyl-7-(4-methoxy-3-(3-methoxypropoxy)
benzyl)-8-methylnonanamide (8q)
Starting with 1 (50 mg, 0.11 mmol) and 5 (41 mg, 0.25 mmol),
8q (41 mg, 63.1%) was obtained as a colorless oil: ½a D23
ꢂ14.2 (c
ꢃ
4.3.12. N-(3-Amino-2,2-dimethylpropyl)-2-phenylacetamide
(7l)
0.11, CHCl3); 1H NMR (300 MHz, CDCl3) d 0.87–0.96 (m, 18H),
1.35–1.45 (m, 1H), 1.50–2.00 (m, 6H), 2.07–2.12 (m, 3H), 2.48–
2.54 (m, 3H), 2.92 (br, 1H), 3.15 (s, 2H), 3.08–3.28 (m, 2H), 3.36
(s, 3H), 3.41 (br, 1H), 3.58 (t, J = 6.3 Hz, 2H), 3.84 (s, 3H), 4.10 (t,
J = 6.6 Hz, 2H), 5.85 (br, 1H), 6.69–6.81 (m, 3H); 13C NMR
(75 MHz, CDCl3) d 17.5, 19.8, 20.3, 21.2, 23.4, 29.6, 29.8, 30.2,
32.1, 34.2, 37.5, 42.5, 47.2, 51.1, 56.1, 58.6, 60.9, 66.1, 66.8, 69.4,
Starting with 6l (120 mg, 0.49 mmol), 7l (100 mg, 93%) was ob-
tained as a white solid: 1H NMR (300 MHz, CDCl3) d 0.96 (s, 6H),
1.80 (br, 2H), 2.68 (s, 2H), 3.36 (d, J = 5.3 Hz, 2H), 3.83 (s, 3H),
6.90 (d, J = 8.6 Hz, 2H), 7.77 (d, J = 8.6 Hz, 2H), 8.25 (br, 1H); 13C
NMR (75 MHz, CDCl3) d 23.8, 34.7, 50.0, 52.1, 55.3, 113.6, 127.2,
128.7, 161.9, 166.9; MS(ESI) m/z 237.2 [M+H]+.

Y. Wu et al. / Bioorg. Med. Chem. 19 (2011) 4238–4249
4245
71.9, 111. 9, 114.2, 121.2, 133.7, 147.8, 148.5, 175.5; MS(ESI) m/z
612.3 [M+Na]+; HRMS for C30H52N7O5+H calcd 590.4030, found
590.4035.
36.0, 37.5, 42.4, 45.5, 46.0, 51.2, 56.1, 58.6, 66.1, 66.3, 69.4, 72.0,
111. 9, 114.2, 121.2, 133.8, 147.8, 148.4, 174.2, 176.4; MS(ESI) m/
z 656.4 [M+Na]+; HRMS for C34H60N5O6+H calcd 634.4544, found
634.4550.
4.4.2. (2S,4S,5S,7S)-N-(3-Acetamido-2,2-dimethylpropyl)-5-
azido-4-hydroxy-2-isopropyl-7-(4-methoxy-3-(3-methoxy
propoxy)benzyl)-8-methylnonanamide (8a)
4.4.6. (2S,4S,5S,7S)-5-Azido-N-(2,2-dimethyl-3-(3-methyl butan-
amido)propyl)-4-hydroxy-2-isopropyl-7-(4-methoxy-3-(3-
methoxypropoxy)benzyl)-8-methylnonanamide (8e)
Starting with 1 (50 mg, 0.11 mmol) and 7a (39.5 mg, 0.25
mmol), 8a (33 mg, 49.6%) was obtained as a colorless oil: ½a D23
ꢃ
Starting with
1 (50 mg, 0.11 mmol) and 7e (46.5 mg,
ꢂ21.6 (c 0.12, CHCl3); 1H NMR (300 MHz, CDCl3) d 0.86–0.96 (m,
18H), 1.32 (m, 1H), 1.61–1.80 (m, 5H), 1.91 (m, 1H), 2.03 (s, 3H),
2.09 (t, J = 6.5 Hz, 2H), 2.12 (br, 1H), 2.50 (m, 2H), 2.92 (m,
3H), 3.12 (m, 2H), 3.36 (s, 3H), 3.42 (br, 1H), 3.58 (t, J = 6.5 Hz,
2H), 3.83 (s, 3H), 4.10 (t, J = 6.5 Hz, 3H), 6.46 (br, 1H), 6.67–6.80
(m, 3H); 13C NMR (75 MHz, CDCl3) d 17.5, 19.9, 20.3, 21.2, 23.3,
23.6, 23.9, 29.6, 30.0, 31.9, 34.3, 36.1, 37.5, 42.5, 45.8, 46.1, 51.2,
56.1, 58.6, 66.2, 66.4, 69.4, 72.0, 112. 0, 114.4, 121.3, 133.9,
147.9, 148.5, 171.1, 176.4; MS(ESI) m/z 606.4 [M+H]+; HRMS for
C32H55N5O6+H calcd 606.4231, found 606.4235.
0.25 mmol), 8e (65 mg, 91.5%) was obtained as a colorless oil:
½
a 2D3
ꢃ
ꢂ37.4 (c 0.12, CHCl3); 1H NMR (300 MHz, CDCl3) d 0.85–0.97
(m, 24H), 1.30–1.40 (m, 1H), 1.58–2.00 (m, 7H), 2.05–2.20 (m,
6H), 2.50 (d, J = 7.1 Hz, 2H), 2.84–2.91 (m, 3H), 3.11–3.24 (m,
2H), 3.36 (s, 3H), 3.42 (br, 1H), 3.58 (t, J = 6.2 Hz, 2H), 3.84 (s,
3H), 4.10 (t, J = 6.5 Hz, 3H), 6.32 (br, 1H), 6.69–6.84 (m, 4H); 13C
NMR (75 MHz, CDCl3) d 17.3, 20.0, 20.2, 20.5, 21.3, 22.4, 23.6,
23.8, 24.0, 26.1, 29.6, 29.8, 31.8, 34.4, 36.0, 37.5, 42.4, 45.5, 46.1,
51.2, 56.1, 58.6, 66.1, 66.3, 69.4, 72.0, 111. 9, 114.3, 121.2, 133.8,
147.8, 148.4, 173.7, 176.3; MS(ESI) m/z 670.5 [M+Na]+; HRMS for
C35H61N5O6+Na calcd 670.4520, found 670.4526.
4.4.3. (2S,4S,5S,7S)-5-Azido-N-(2,2-dimethyl-3-(2,2,2-trifluor
oacetamido)propyl)-4-hydroxy-2-isopropyl-7-(4-methoxy-3-(3-
methoxypropoxy)benzyl)-8-methylnonanamide (8b)
4.4.7. (2S,4S,5S,7S)-5-Azido-N-(2,2-dimethyl-3-pivalami do-
propyl)-4-hydroxy-2-isopropyl-7-(4-methoxy-3-(3-methoxy-
propoxy)benzyl)-8-methylnonanamide (8f)
Starting with
1 (50 mg, 0.11 mmol) and 7b (49.5 mg,
0.25 mmol), 8b (45 mg, 62.0%) was obtained as a colorless oil:
Starting with
1
(50 mg, 0.11 mmol) and 7f (46.6 mg,
½
a 2D3
ꢃ
ꢂ5.4 (c 0.14, CHCl3); 1H NMR (300 MHz, CDCl3) d 0.88–0.96
0.25 mmol), 8f (42 mg, 58.8%) was obtained as a colorless oil:
(m, 18H), 1.35–1.40 (m, 1H), 1.50–1.91 (m, 6H), 2.07–2.14 (m,
3H), 2.27 (br, 1H), 2.40–2.47 (dd, J = 13.8, 7.5 Hz, 1H), 2.56–2.62
(dd, J = 13.6, 6.6 Hz, 1H), 2.83–3.00 (m, 3H), 3.12–3.19 (dd,
J = 14.4, 6.9 Hz, 2H), 3.30 (br, 1H), 3.36 (s, 3H), 3.58 (t, J = 6.1 Hz,
2H), 3.84 (s, 3H), 4.10 (t, J = 6.5 Hz, 3H), 6.16 (br, 1H), 6.69–6.81
(m, 3H), 8.54 (br, 1H); 13C NMR (75 MHz, CDCl3) d 17.8, 19.6,
20.2, 21.1, 23.5, 23.6, 29.6, 30.1, 30.4, 32.4, 34.1, 36.7, 37.6, 42.5,
45.4, 46.7, 50.7, 56.1, 58.6, 66.2, 66.7, 69.4, 72.0, 111. 9, 114.3,
121.3, 133.7, 147.9, 148.5, 157.6, 158.1, 177.3; MS(ESI) m/z 660.4
[M+H]+; HRMS for C32H52N5O6F3+H calcd 660.3948, found
660.3959.
½
a 2D3
ꢃ
ꢂ33.4 (c 0.10, CHCl3); 1H NMR (300 MHz, CDCl3) d 0.84–0.97
(m, 18H), 1.23 (s, 9H), 1.26–1.35 (m, 1H), 1.55–2.00 (m, 6H),
2.00–2.25 (m, 3H), 2.50 (d, J = 6.6 Hz, 2H), 2.77–2.95 (m, 4H),
3.13–3.22 (m, 2H), 3.36 (s, 3H), 3.41 (br, 1H), 3.58 (t, J = 6.3 Hz,
2H), 3.83 (s, 3H), 4.10 (t, J = 6.5 Hz, 2H), 6.47 (br, 1H), 6.68–6.80
(m, 4H), 6.84 (br, 1H); 13C NMR (75 MHz, CDCl3) d 17.2, 20.0,
20.2, 21.3, 23.5, 23.9, 27.6, 29.5, 29.6, 29.8, 31.8, 34.4, 37.5, 38.9,
42.4, 45.3, 45.9, 51.2, 56.1, 58.6, 66.1, 66.3, 69.4, 72.1, 111. 9,
114.3, 121.2, 133.8, 147.8, 148.4, 176.3, 179.9; MS(ESI) m/z 670.5
[M+Na]+; HRMS for C35H61N5O6+Na calcd 670.4520, found
670.4528.
4.4.4. (2S,4S,5S,7S)-5-Azido-N-(2,2-dimethyl-3-
propionamidopropyl)-4-hydroxy-2-isopropyl-7-(4-methoxy-3-
(3-methoxypropoxy)benzyl)-8-methylnonanamide (8c)
4.4.8. (2S,4S,5S,7S)-5-Azido-N-(3-hexanamido-2,2-dimethyl
propyl)-4-hydroxy-2-isopropyl-7-(4-methoxy-3-(3-methoxy
propoxy)benzyl)-8-methylnonanamide (8g)
Starting with
1
(50 mg, 0.11 mmol) and 7c (46.5 mg,
Starting with 1 (50 mg, 0.11 mmol) and 7g (50 mg, 0.25 mmol),
0.25 mmol), 8c (40 mg, 57.4%) was obtained as a colorless oil:
8g (60 mg, 82.4%) was obtained as a colorless oil: ½a D23
ꢂ28.3 (c
ꢃ
½
a 2D3
ꢃ
ꢂ6.6 (c 0.19, CHCl3); 1H NMR (300 MHz, CDCl3) d 0.85–0.97
0.63, CHCl3); 1H NMR (300 MHz, CDCl3) d 0.85–0.96 (m, 21H),
1.26–1.41 (m, 5H), 1.58–1.81 (m, 8H), 1.81–2.00 (m, 1H), 2.00–
2.25 (m, 5H), 2.49 (d, J = 7.1 Hz, 2H), 2.84–2.94 (m, 3H), 3.12–
3.22 (m, 2H), 3.36 (s, 3H), 3.43 (br, 1H), 3.58 (t, J = 6.2 Hz, 2H),
3.84 (s, 3H), 4.10 (t, J = 6.5 Hz, 2H), 6.39 (br, 1H), 6.69–6.84 (m,
4H); 13C NMR (75 MHz, CDCl3) d 13.9, 17.3, 20.0, 20.2, 21.3, 22.3,
23.5, 23.9, 25.5, 29.5, 29.6, 29.8, 31.4, 31.8, 34.3, 36.0, 36.9, 37.5,
42.4, 45.6, 46.0, 51.2, 56.1, 58.6, 66.1, 66.4, 69.4, 72.0, 111. 9,
114.3, 121.2, 133.8, 147.8, 148.4, 174.4, 176.4; MS(ESI) m/z 662.5
[M+H]+; HRMS for C36H63N5O6+H calcd 662.4857, found 662.4838.
(m, 18H), 1.82 (t, J = 7.6 Hz, 3H), 1.30–1.40 (m, 1H), 1.59–1.92
(m, 7H), 2.05–2.22 (m, 3H), 2.22–2.35 (m, 2H), 2.50 (d, J = 7.1 Hz,
1H), 2.83–2.99 (m, 3H), 3.11–3.23 (m, 2H), 3.36 (s, 3H), 3.36–
3.50 (br, 1H), 3.58 (t, J = 6.2 Hz, 2H), 3.84 (s, 3H), 4.10 (t,
J = 6.5 Hz, 3H), 6.38 (br, 1H), 6.69–6.80 (m, 4H); 13C NMR
(75 MHz, CDCl3) d 10.0, 17.4, 20.0, 20.3, 21.3, 23.5, 23.9, 29.5,
29.6, 29.9, 31.8, 34.4, 36.1, 37.5, 42.5, 45.6, 46.0, 51.2, 56.1, 58.6,
66.1, 66.4, 69.4, 72.0, 111. 9, 114.3, 121.2, 133.9, 147.8, 148.5,
175.1, 176.4; MS(ESI) m/z 642.4 [M+Na]+; HRMS for C33H56N5O6+-
Na calcd 642.4207, found 642.4214.
4.4.9. (2S,4S,5S,7S)-5-Azido-N-(2,2-dimethyl-3-(4-methylphenyl
sulfonamido)propyl)-4-hydroxy-2-isopropyl-7-(4-methoxy-3-
(3-methoxypropoxy)benzyl)-8-methylnonanamide (8h)
Starting with 1 (50 mg, 0.11 mmol) and 7h (64 mg, 0.25 mmol),
4.4.5. (2S,4S,5S,7S)-5-Azido-N-(3-butyramido-2,2-dimethyl-
propyl)-4-hydroxy-2-isopropyl-7-(4-methoxy-3-(3-methoxy-
propoxy)benzyl)-8-methylnonanamide (8d)
Starting with 1 (50 mg, 0.11 mmol) and 7d (43 mg, 0.25 mmol),
8h (36 mg, 45.6%) was obtained as a colorless oil: ½a D23
ꢂ3.0 (c 0.11,
ꢃ
8d (39 mg, 56%) was obtained as a colorless oil: ½a D23
ꢃ
ꢂ29.8 (c 0.63,
CHCl3); 1H NMR (300 MHz, CDCl3) d 0.76–0.93 (m, 18H),1.30–1.40
(m, 1H), 1.49–1.85 (m, 6H), 2.02–2.13 (m, 3H), 2.40 (s, 3H), 2.42–
2.66 (m, 4H), 2.82–2.98 (m, 2H), 3.23–3.35 (m, 2H), 3.35 (s, 3H),
3.57 (t, J = 6.2 Hz, 2H), 3.84 (s, 3H), 4.10 (t, J = 6.5 Hz, 2H), 6.12
(br, 2H), 6.69–6.81 (m, 3H), 7.26–7.73 (m, 5H); 13C NMR
(75 MHz, CDCl3) d 17.7, 19.7, 20.2, 21.0, 21.4, 23.6, 23.8, 29.6,
29.8, 30.2, 32.1, 34.2, 35.7, 37.5, 42.5, 46.4, 50.1, 50.7, 56.1, 58.6,
CHCl3); 1H NMR (300 MHz, CDCl3) d 0.85–0.98 (m, 21H), 1.26–1.34
(m, 1H), 1.59–2.00 (m, 9H), 2.00–2.23 (m, 5H), 2.50 (d, J = 7.1 Hz,
2H), 2.84–2.90 (m, 3H), 3.10–3.23 (m, 2H), 3.36 (s, 3H), 3.36–3.55
(br, 1H), 3.58 (t, J = 6.1 Hz, 2H), 3.83 (s, 3H), 4.10 (t, J = 6.4 Hz,
3H), 6.30 (br, 1H), 6.68–6.99 (m, 4H); 13C NMR (75 MHz, CDCl3) d
13.7, 17.3, 19.2, 20.0, 20.3, 21.3, 23.5, 23.9, 29.5, 29.8, 31.8, 34.4,

4246
Y. Wu et al. / Bioorg. Med. Chem. 19 (2011) 4238–4249
66.1, 66.5, 69.4, 71.9, 111. 9, 114.3, 121.3, 126.9, 129.6, 133.7,
137.3,143.0, 147.8, 148.4, 176.6; MS(ESI) m/z 740.4 [M+Na]+;
HRMS for C37H59N5O7S+ Na calcd 740.4033, found 740.4052.
147.8, 148.4, 172.3, 176.2; MS(ESI) m/z 682.5 [M+H]+; HRMS for
38H59N5O6+H calcd 682.4544, found 682.4532.
C
4.4.14. (2S,4S,5S,7S)-5-Azido-N-(2,2-dimethyl-3-(methyl
sulfonamido)propyl)-4-hydroxy-2-isopropyl-7-(4-methoxy-3-
(3-methoxypropoxy)benzyl)-8-methylnonanamide (8m)
Starting with 1 (50 mg, 0.11 mmol) and 7m (45 mg, 0.25 mmol),
4.4.10. Ethyl (3-((2S,4S,5S,7S)-5-Azido-4-hydroxy-2-isopropyl-7-
(4-methoxy-3-(3-methoxypropoxy)benzyl)-8-methyl
nonanamido)-2,2-dimethylpropyl)carbamate (8i)
Starting with 1 (50 mg, 0.11 mmol) and 7i (43.5 mg, 0.25
8m (35 mg, 49.6%) was obtained as a colorless oil: ½a D23
ꢂ20.1 (c
ꢃ
mmol), 8i (40 mg, 57%) was obtained as a colorless oil: ½a D23
ꢃ
0.28, CHCl3); 1H NMR (300 MHz, CDCl3) d 0.72–0.95 (m, 18H),
1.30–1.40 (m, 1H), 1.50–1.95 (m, 6H), 2.05–2.18 (m, 3H),
2.44–2.70 (m, 3H), 2.74–3.20 (m, 5H), 2.90 (s, 3H), 3.35 (s, 3H),
3.37 (br, 1H), 3.58 (t, J = 6.1 Hz, 2H), 3.83 (s, 3H), 4.10 (t,
J = 6.6 Hz, 2H), 5.95 (br, 1H), 6.18 (br, 1H), 6.69–6.83 (m, 3H); 13C
NMR (75 MHz, CDCl3) d 17.7, 19.7, 20.3, 21.1, 23.5, 23.7, 29.6,
29.9, 30.2, 32.1, 34.1, 35.8, 37.6, 39.8, 42.5, 46.4, 50.0, 50.7, 56.1,
58.6, 66.2, 66.6, 69.4, 72.0, 112.0, 114.4, 121.3, 133.8, 147.9,
148.5, 176.8; MS(ESI) m/z 642.4 [M+H]+; HRMS for C31H55N5O7S+H
calcd 642.3900, found 642.3909.
ꢂ27.5 (c 0.11, CHCl3); 1H NMR (300 MHz, CDCl3) d 0.85–0.96 (m,
18H), 1.24 (t, J = 7.1 Hz, 3H), 1.30–1.39 (m, 1H), 1.50–2.00 (m,
6H), 2.07–2.12 (m, 3H), 2.50(d, J = 7.0 Hz, 2H), 2.88–3.22 (m, 5H),
3.36 (s, 3H), 3.43 (br, 1H), 3.58 (t, J = 6.1 Hz, 2H), 3.84 (s, 3H),
4.10 (m, 4H), 5.47 (br, 1H), 6.59 (br, 1H),6.71–6.80 (m, 3H); 13C
NMR (75 MHz, CDCl3) d 14.6, 17.4, 19.9, 20.3, 21.2, 23.3, 23.7,
29.6, 30.0, 31.9, 34.3, 36.1, 37.5, 42.5, 45.6, 47.7, 51.2, 56.1, 58.6,
66.1, 66.5, 69.4, 72.1, 111. 9, 114.2, 121.2, 133.8, 147.8, 148.4,
157.8, 176.1; MS(ESI) m/z 658.4 [M+Na]+; HRMS for C33H57N5O7+-
Na calcd 658.4156, found 658.4172.
4.4.15. (2S,4S,5S,7S)-5-Azido-N-(3-(ethylsulfonamido)-2,2-
dimethylpropyl)-4-hydroxy-2-isopropyl-7-(4-methoxy-3-
(3-methoxypropoxy)benzyl)-8-methylnonanamide (8n)
Starting with 1 (50 mg, 0.11 mmol) and 7n (49 mg, 0.25 mmol),
4.4.11. N-(3-((2S,4S,5S,7S)-5-Azido-4-hydroxy-2-isopropyl-7-
(4-methoxy-3-(3-methoxypropoxy)benzyl)-8-methyl nonan-
amido)-2,2-dimethylpropyl)benzamide (8j)
8n (35 mg, 48.5%) was obtained as a colorless oil: ½a D23
ꢃ
ꢂ16.9 (c
Starting with
1
(50 mg, 0.11 mmol) and 7j (51.5 mg,
0.34, CHCl3); 1H NMR (300 MHz, CDCl3) d 0.89–0.96 (m, 18H),
1.30–1.40 (m, 1H), 1.35 (t, J = 7.4 Hz, 3H), 1.50–1.95 (m, 6H),
2.04–2.18 (m, 3H), 2.44–2.60 (m, 2H), 2.60–2.68 (m, 1H), 2.72–
2.83 (m, 2H), 2.91 (br, 1H), 2.97–3.09 (m, 1H), 3.13–3.25 (m, 1H),
3.37 (s, 3H), 3.41 (br, 1H), 3.59 (t, J = 6.2 Hz, 2H), 3.85 (s, 3H),
4.11 (t, J = 6.5 Hz, 2H), 5.87 (br, 1H), 6.18 (br, 1H), 6.71–6.84 (m,
3H); 13C NMR (75 MHz, CDCl3) d 8.2, 17.6, 19.8, 20.3, 21.1, 23.5,
23.6, 29.6, 29.9, 30.2, 32.1, 34.1, 35.9, 37.6, 42.5, 46.3, 46.7, 50.0,
50.7, 56.1, 58.6, 66.2, 66.6, 69.4, 72.0, 112.0, 114.3, 121.3, 133.8,
147.9, 148.5, 176.7; MS(ESI) m/z 678.4 [M+Na]+; HRMS for
C32H57N5O7S+Na calcd 678.3876, found 678.3888.
0.25 mmol), 8j (41 mg, 55.8%) was obtained as a colorless oil:
½
a 2D3
ꢃ
ꢂ28.3 (c 0.26, CHCl3); 1H NMR (300 MHz, CDCl3) d 0.82–0.96
(m, 18H), 1.35–1.45 (m, 1H), 1.57–2.01 (m, 6H), 2.01–2.13 (m,
2H), 2.20 (m, 1H), 2.48 (m, 3H), 2.85–3.25 (m, 4H), 3.36 (s, 3H),
3.30–3.47 (m, 2H), 3.59 (t, J = 6.2 Hz, 2H), 3.84 (s, 3H), 4.09 (t,
J = 6.5 Hz, 2H), 6.67–6.78 (m, 4H),7.43–7.89 (m, 6H); 13C NMR
(75 MHz, CDCl3) d 17.4, 19.9, 20.3, 21.3, 23.7, 24.0, 29.6, 29.7,
30.1, 32.0, 34.3, 36.6, 37.5, 42.5, 46.1, 51.1, 56.1, 58.6, 66.1, 66.4,
69.4, 72.1, 111. 9, 114.3, 121.2, 127.0, 128.6, 131.6, 133.8, 134.1,
147.8, 148.4, 168.1, 176.6; MS(ESI) m/z 690.4 [M+Na]+; HRMS for
C37H57N5O6+Na calcd 690.4207, found 690.4211.
4.4.12. N-(3-((2S,4S,5S,7S)-5-Azido-4-hydroxy-2-isopropyl-7-
(4-methoxy-3-(3-methoxypropoxy)benzyl)-8-methyl nonan-
amido)-2,2-dimethylpropyl)-4-methoxybenzamide (8k)
Starting with 1 (50 mg, 0.11 mmol) and 7k (59 mg, 0.25 mmol),
4.4.16. (2S,4S,5S,7S)-5-Azido-N-(3-(3,3-dimethylureido)-2,2-
dimethylpropyl)-4-hydroxy-2-isopropyl-7-(4-methoxy-3-(3-
methoxypropoxy)benzyl)-8-methylnonanamide (8o)
Starting with
1 (50 mg, 0.11 mmol) and 7o (43.3 mg,
8k (45 mg, 58.6%) was obtained as a colorless oil: ½a D23
ꢂ29.9 (c
ꢃ
0.25 mmol), 8o (54 mg, 77%) was obtained as a colorless oil: ½a D23
ꢃ
0.18, CHCl3); 1H NMR (300 MHz, CDCl3) d 0.82–0.98 (m, 18H),
1.35–1.45 (m, 1H), 1.57–2.00 (m, 6H), 2.00–2.15 (m, 2H), 2.19
(m, 1H), 2.48 (d, J = 7.1 Hz, 2H), 2.38–2.52 (br, 1H), 2.85–3.25 (m,
4H), 3.36 (s, 3H), 3.40 (m, 2H), 3.57 (t, J = 6.2 Hz, 2H), 3.82 (s,
3H), 3.84 (s, 3H), 4.09 (t, J = 6.4 Hz, 2H), 6.67–6.78 (m, 4H), 7.27
(br, 1H), 6.95–7.85 (m, 4H); 13C NMR (75 MHz, CDCl3) d 17.4,
19.9, 20.3, 21.3, 23.7, 24.0, 29.6, 30.0, 31.9, 34.4, 36.5, 37.5, 42.5,
45.9, 46.1, 51.2, 55.4, 56.1, 58.6, 66.1, 66.4, 69.4, 72.1, 111.9,
113.8, 114.3, 121.2, 126.3, 128.9, 133.8, 147.8, 148.4, 162.3,
167.6, 176.5; MS(ESI) m/z 698.5 [M+H]+; HRMS for C38H59N5O7+H
calcd 698.4493, found 698.4506.
ꢂ49.1 (c 0.41, CHCl3); 1H NMR (300 MHz, CDCl3) d 0.83–0.96 (m,
18H), 1.26–1.35 (m, 1H), 1.55–2.00 (m, 6H), 2.05–2.22 (m, 3H),
2.51 (m, 2H), 2.79–3.30 (m, 5H), 2.93 (s, 6H), 3.36 (s, 3H), 3.45
(br, 1H), 3.57 (t, J = 6.1 Hz, 2H), 3.83 (s, 3H), 4.10 (t, J = 6.5 Hz,
2H), 5.07 (br, 1H), 6.68–6.80 (m, 3H), 7.15 (br, 1H); 13C NMR
(75 MHz, CDCl3) d 17.2, 20.1, 20.2, 21.3, 23.4, 24.0, 29.4, 29.6,
31.7, 34.6, 35.8, 36.3, 37.5, 42.5, 45.2, 47.5, 51.2, 56.1, 58.6, 66.1,
66.5, 69.4, 72.1, 111.9, 114.3, 121.2, 133.9, 147.8, 159.0, 176.1;
MS(ESI) m/z 635.5 [M+H]+; HRMS for C33H58N6O6+H calcd
635.4496, found 635.4508.
4.4.17. (2S,4S,5S,7S)-5-Azido-N-(2,2-dimethyl-3-(sulfamoy
lamino)propyl)-4-hydroxy-2-isopropyl-7-(4-methoxy-3-
(3-methoxypropoxy)benzyl)-8-methylnonanamide (8p)
4.4.13. (2S,4S,5S,7S)-5-Azido-N-(2,2-dimethyl-3-(2-phenyl
acetamido)propyl)-4-hydroxy-2-isopropyl-7-(4-methoxy-3-
(3-methoxypropoxy)benzyl)-8-methylnonanamide (8l)
Starting with 1 (50 mg, 0.11 mmol) and 7l (55 mg, 0.25 mmol),
Starting with
1 (50 mg, 0.11 mmol) and 7p (45.3 mg,
8l (42 mg, 56%) was obtained as a colorless oil: ½a D23
ꢃ
ꢂ30.5 (c 0.27,
0.25 mmol), 8p (45 mg, 63.6%) was obtained as a colorless oil:
a 2D3
ꢃ
ꢂ12.5 (c 0.20, CHCl3); 1H NMR (300 MHz, CDCl3) d 0.84–0.96
CHCl3); 1H NMR (300 MHz, CDCl3) d 0.77–0.96 (m, 18H), 1.30–1.40
(m, 1H), 1.55–2.00 (m, 7H), 2.00–2.22 (m, 3H), 2.50–2.51 (d,
J = 7.1 Hz, 2H), 2.77–3.17 (m, 5H), 3.35 (s, 3H), 3.45 (br, 1H), 3.57
(m, 4H), 3.83 (s, 3H), 4.10 (t, J = 6.5 Hz, 2H), 6.16 (br, 1H), 6.69–
6.83 (m, 4H), 7.28–7.40 (m, 5H); 13C NMR (75 MHz, CDCl3) d
17.3, 20.0, 20.2, 21.3, 23.4, 23.8, 29.5, 29.6, 29.8, 31.7, 34.2, 36.2,
37.5, 42.5, 43.9, 45.4, 46.2, 51.2, 56.1, 58.6, 66.1, 66.3, 69.4, 71.9,
111.9, 114.3, 121.2, 127.1, 127.5, 129.1, 129.2, 133.9, 134.8,
½
(m, 18H), 1.30–1.40 (m, 1H), 1.50–2.00 (m, 6H), 2.03–2.18 (m,
4H), 2.38–2.65 (m, 2H), 2.70–3.23 (m, 5H), 3.37 (s, 3H), 3.44 (br,
1H), 3.58 (t, J = 6.1 Hz, 2H), 3.85 (s, 3H), 4.11 (t, J = 6.5 Hz, 2H),
4.83 (br, 2H), 5.82 (br, 1H), 6.17 (br, 1H), 6.72–6.83 (m, 3H); 13C
NMR (75 MHz, CDCl3) d 17.9, 19.5, 20.3, 21.2, 23.8, 23.9, 29.5,
30.0, 30.1, 32.2, 34.1, 35.5, 37.5, 42.6, 46.5, 50.3, 50.9, 56.1, 58.6,
66.1, 66.6, 69.4, 71.8, 111.8, 114.2, 121.3, 133.8, 147.7, 148.3,

Y. Wu et al. / Bioorg. Med. Chem. 19 (2011) 4238–4249
4247
176.9; MS(ESI) m/z 665.4 [M+Na]+; HRMS for C30H54N6O7S+Na
calcd 665.3668, found 665.3668.
J = 6.6 Hz, 2H), 6.36 (br, 1H), 6.67–6.79 (m, 3H), 8.71 (br, 1H); 13C
NMR (75 MHz, CDCl3) d 17.6, 17.8, 19.8, 20.3, 21.2, 23.5, 23.6,
29.6, 30.0, 30.4, 30.7, 34.8, 35.6, 36.6, 37.9, 42.6, 45.3, 46.6, 51.1,
54.6, 56.0, 58.6, 66.3, 69.4, 71.9, 111. 9, 114.4, 121.2, 134.0,
147.8, 148.4, 177.7; MS(ESI) m/z 634.4 [M+H]+; HRMS for
4.4.18. (2S,4S,5S,7S)-5-Azido-N-(2,2-dimethyl-3-(1H-1,2,3-
triazol-1-yl)propyl)-4-hydroxy-2-isopropyl-7-(4-methoxy-3-
(3-methoxypropoxy)benzyl)-8-methylnonanamide (8r)
C32H54N3O6F3+H calcd 634.4043, found 634.4048.
Starting with
1
(50 mg, 0.11 mmol) and 7r (38.5 mg,
0.25 mmol), 8r (43 mg, 64%) was obtained as a colorless oil: ½a D23
ꢃ
4.5.4. (2S,4S,5S,7S)-5-Amino-N-(2,2-dimethyl-3-propion-
amidopropyl)-4-hydroxy-2-isopropyl-7-(4-methoxy-3-
(3-methoxypropoxy)benzyl)-8-methylnonanamide (9c)
Starting with 8c (14.8 mg, 0.024 mmol), 9c (13 mg, 91.5%) was
ꢂ19.2 (c 0.27, CHCl3); 1H NMR (300 MHz, CDCl3) d 0.86–0.97 (m,
18H), 1.30–1.40 (m, 1H), 1.50–2.00 (m, 6H), 2.04–2.22 (m, 3H),
2.50 (m, 2H), 2.93–3.18 (m, 4H), 3.35 (s, 3H), 3.44 (br, 1H), 3.57
(t, J = 6.2 Hz, 2H), 3.83 (s, 3H), 4.10 (t, J = 6.5 Hz, 2H), 4.20 (s, 2H),
6.40 (br, 1H), 6.68–6.80 (m, 3H), 7.67 (s, 1H), 7.71 (s, 1H); 13C
NMR (75 MHz, CDCl3) d 17.5, 19.9, 20.2, 21.2, 23.9, 24.0, 29.6,
29.7, 30.1, 32.0, 34.1, 37.1, 37.5, 42.5, 46.2, 51.1, 56.1, 57.5, 58.6,
66.2, 66.6, 69.4, 71.9, 111.9, 114.3, 121.2, 125.1, 133.6, 133.8,
147.8, 148.5, 176.1; MS(ESI) m/z 638.4 [M+Na]+; HRMS for
obtained as a colorless oil: ½a D23
ꢃ
ꢂ7.2 (c 0.13, CHCl3); 1H NMR
(300 MHz, CDCl3) d 0.84–0.96 (m, 18H), 1.18–1.21 (m, 3H), 1.15–
1.45 (m, 3H), 1.60–1.95 (m, 5H), 1.95–2.29 (m, 8H), 2.46–2.48
(m, 2H), 2.90–3.17 (m, 5H), 3.36 (s, 3H), 3.58 (t, J = 6.1 Hz, 2H),
3.83 (s, 3H), 4.10 (t, J = 6.5 Hz, 2H), 6.49 (br, 1H), 6.68–6.82 (m,
4H); 13C NMR (75 MHz, CDCl3) d 10.2, 17.4, 19.9, 20.3, 21.2, 23.6,
23.8, 27.0, 29.6, 30.0, 30.4, 34.8, 35.4, 36.3, 37.8, 42.5, 45.4, 46.2,
51.3, 54.6, 56.0, 58.7, 66.2, 69.4, 72.0, 111. 8, 114.4, 121.2, 134.1,
147.7, 148.3, 174.5, 176.8; MS(ESI) m/z 594.4 [M+H]+; HRMS for
C
33H53N7O5+Na calcd 638.4006, found 638.4014.
4.5. General procedure for the preparation of 9a–r
solution of 8a–r (0.02–0.05 mmol) and ethanolamine
C33H59N3O6+H calcd 594.4482, found 594.4487.
A
(1 equiv) in methyl tert-butyl ether (5 mL) was hydrogenated in
the presence of 5 mg of 10% Pd/C (moist) at 25 °C over 0.5–1 h.
The reaction mixture was filtered and the solids were washed with
CH2Cl2. The filtrate was washed with 2 N NaOH aqueous solution,
dried and concentrated under reduced pressure.
4.5.5. (2S,4S,5S,7S)-5-Amino-N-(3-butyramido-2,2-dimethyl-
propyl)-4-hydroxy-2-isopropyl-7-(4-methoxy-3-(3-methoxy-
propoxy)benzyl)-8-methylnonanamide (9d)
Starting with 8d (20 mg, 0.031 mmol), 9d (16 mg, 83%) was ob-
tained as a colorless oil: ½a D23
ꢃ
ꢂ7.8 (c 0.28, CHCl3); 1H NMR
(300 MHz, CDCl3) d 0.84–0.98 (m, 21H), 1.18–1.45 (m, 3H), 1.62–
1.95 (m, 6H), 1.95–2.27 (m, 8H), 2.23 (br, 1H), 2.47 (d, J = 7.0 Hz,
2H), 2.90–3.14 (m, 5H), 3.36 (s, 3H), 3.58 (t, J = 6.1 Hz, 2H), 3.83
(s, 3H), 4.10 (t, J = 6.5 Hz, 2H), 6.48 (br, 1H), 6.68–6.82 (m, 3H),
6.85 (br, 1H); 13C NMR (75 MHz, CDCl3) d 13.8, 17.6, 19.9, 20.0,
20.3, 21.2, 23.6, 23.8, 2, 29.6, 29.7, 30.4, 34.8, 35.3, 36.2, 37.8,
39.0, 42.5, 45.4, 46.2, 51.3, 54.7, 56.1, 58.6, 66.2, 69.4, 72.0, 111.
9, 114.4, 121.2, 134.1, 147.8, 148.4, 173.7, 176.8; MS(ESI) m/z
608.5 [M+H]+; HRMS for C34H61N3O6+H calcd 608.4629, found
608.4643.
4.5.1. (2S,4S,5S,7S)-5-Amino-N-(3-amino-2,2-dimethylpropyl)-
4-hydroxy-2-isopropyl-7-(4-methoxy-3-(3-methoxypropoxy)-
benzyl)-8-methylnonanamide (9q)
Starting with 8q (37 mg, 0.06 mmol), 9q (30 mg, 89%) was ob-
tained as a colorless oil: ½a D23
ꢃ
ꢂ8.8 (c 0.18, CHCl3); 1H NMR
(300 MHz, CDCl3) d 0.84–1.00 (m, 18H), 1.15–1.48 (m, 3H), 1.60–
2.00 (m, 11H), 2.34 (br, 1H), 2.46–2.51 (d, J = 6.8 Hz, 2H), 2.52 (s,
2H), 3.04–3.27 (m, 3H), 3.36 (s, 3H), 3.58 (t, J = 6.0 Hz, 2H), 3.83
(s, 3H), 4.10 (t, J = 6.3 Hz, 2H), 6.68–6.82 (m, 3H), 6.85 (br, 1H);
13C NMR (75 MHz, CDCl3) d 17.4, 20.1, 20.4, 21.3, 23.6, 23.7, 27.0,
29.6, 30.5, 34.8, 35.2, 35.3, 37.8, 42.6, 47.5, 51.0, 51.4, 54.6, 56.0,
58.7, 66.2, 69.4, 72.1, 111. 8, 114.3, 121.2, 134.2, 147.7, 148.3,
175.7; MS(ESI) m/z 538.4 [M+H]+; HRMS for C30H55N3O5+H calcd
538.4220, found 538.4226.
4.5.6. (2S,4S,5S,7S)-5-Amino-N-(2,2-dimethyl-3-(3-methyl-
butanamido)propyl)-4-hydroxy-2-isopropyl-7-(4-methoxy-
3-(3-methoxypropoxy)benzyl)-8-methylnonanamide (9e)
Starting with 8e (28 mg, 0.043 mmol), 9e (24 mg, 89.2%) was
obtained as a colorless oil: ½a D23
ꢃ
ꢂ5.3 (c 0.18, CHCl3); 1H NMR
4.5.2. (2S,4S,5S,7S)-N-(3-Acetamido-2,2-dimethylpropyl)-5-
amino-4-hydroxy-2-isopropyl-7-(4-methoxy-3-(3-methoxy-
propoxy)benzyl)-8-methylnonanamide (9a)
(300 MHz, CDCl3) d 0.84–0.97 (m, 24H), 1.19–1.44 (m, 3H), 1.66–
2.00 (m, 6H), 2.00–2.21 (m, 7H), 2.31 (br, 1H), 2.47 (d, J = 6.6 Hz,
2H), 2.91–3.20 (m, 5H), 3.36 (s, 3H), 3.58 (t, J = 6.1 Hz, 2H), 3.83
(s, 3H), 4.10 (t, J = 6.5 Hz, 2H), 6.52 (br, 1H), 6.68–6.79 (m, 4H);
13C NMR (75 MHz, CDCl3) d 17.4, 20.1, 20.3, 21.2, 22.5, 23.6, 23.8,
29.6, 29.7, 30.4, 34.8, 35.4, 36.2, 37.8, 42.5, 45.4, 46.1, 46.4, 51.3,
54.6, 56.0, 58.6, 66.2, 69.4, 72.1, 111. 8, 114.4, 121.2, 134.2,
147.8, 148.3, 173.1, 176.7; MS(ESI) m/z 622.5 [M+H]+; HRMS for
Starting with 8a (25 mg, 0.04 mmol), 9a (21 mg, 87.9%) was ob-
tained as a colorless oil: ½a D23
ꢃ
ꢂ15.7 (c 0.12, CHCl3); 1H NMR
(300 MHz, CDCl3) d 0.85–0.97 (m, 18H), 1.25–1.43 (m, 3H), 1.66–
2.22 (m, 10H), 2.02 (s, 3H), 2.48 (m, 1H), 2.31 (br, 1H), 2.89–3.11
(m, 5H), 3.36 (s, 3H), 3.58 (t, J = 6.0 Hz, 2H), 3.83 (s, 3H), 4.10 (t,
J = 6.3 Hz, 2H), 6.48 (br, 1H), 6.68–6.79 (m, 3H), 6.94 (br, 1H); 13C
NMR (75 MHz, CDCl3) d 17.5, 20.0, 20.3, 21.2, 23.5, 23.6, 23.7,
29.6, 29.7, 30.5, 34.8, 35.4, 36.3, 37.8, 42.6, 45.6, 46.3, 51.3, 54.6,
56.1, 58.7, 66.2, 69.4, 72.0, 111. 9, 114.4, 121.2, 134.1, 147.8,
148.4, 170.7, 176.9; MS(ESI) m/z 580.4 [M+H]+; HRMS for
C35H63N3O6+H calcd 622.4795, found 622.4806.
4.5.7. (2S,4S,5S,7S)-5-Amino-N-(2,2-dimethyl-3-
pivalamidopropyl)-4-hydroxy-2-isopropyl-7-(4-methoxy-3-
(3-methoxypropoxy)benzyl)-8-methylnonanamide (9f)
Starting with 8f (32 mg, 0.045 mmol), 9f (26 mg, 84.4%) was ob-
C32H58N3O6+H calcd 580.4326, found 580.4332.
tained as a colorless oil: ½a D23
ꢃ
ꢂ7.9 (c 0.12, CHCl3); 1H NMR
4.5.3. (2S,4S,5S,7S)-5-Amino-N-(2,2-dimethyl-3-(2,2,2-trifluoro
acetamido)propyl)-4-hydroxy-2-isopropyl-7-(4-methoxy-3-
(3-methoxypropoxy)benzyl)-8-methylnonanamide (9b)
Starting with 8b (17.5 mg, 0.03 mmol), 9b (14 mg, 83.3%) was
(300 MHz, CDCl3) d 0.84–0.96 (m, 18H), 1.24 (s, 9H), 1.15–1.45
(m, 3H), 1.61–2.00 (m, 6H), 2.00–2.22 (m, 4H), 2.31 (br, 1H), 2.47
(d, J = 6.7 Hz, 2H), 2.88–3.19 (m, 5H), 3.36 (s, 3H), 3.58 (t,
J = 6.1 Hz, 2H), 3.84 (s, 3H), 4.10 (t, J = 6.5 Hz, 2H), 6.55 (br, 1H),
6.68–6.79 (m, 3H), 6.97 (br, 1H); 13C NMR (75 MHz, CDCl3) d
17.4, 20.1, 20.3, 21.2, 23.6, 23.8, 27.7, 29.6, 30.3, 34.7, 35.4, 36.3,
37.8, 38.9, 42.5, 45.2, 45.9, 51.3, 54.6, 56.0, 58.7, 66.2, 69.4, 72.1,
111. 8, 114.3, 121.2, 134.1, 147.7, 148.3, 159.8, 176.6, 179.3;
obtained as a colorless oil: ½a D23
ꢃ
ꢂ4.8 (c 0.18, CHCl3); 1H NMR
(300 MHz, CDCl3) d 0.85–0.96 (m, 18H), 1.26–1.39 (m, 3H), 1.65–
2.00 (m, 5H), 2.07–2.24 (m, 6H), 2.43–2.53(m, 2H), 2.98–3.21 (m,
5H), 3.36 (s, 3H), 3.58 (t, J = 6.3 Hz, 2H), 3.83 (s, 3H), 4.10 (t,

4248
Y. Wu et al. / Bioorg. Med. Chem. 19 (2011) 4238–4249
MS(ESI) m/z 622.5 [M+H]+; HRMS for C31H63N3O6+H calcd
622.4795, found 622.4790.
642.4 [M+H]+; HRMS for C37H59N3O6+H calcd 642.4482, found
642.4485.
4.5.8. (2S,4S,5S,7S)-5-Amino-N-(3-hexanamido-2,2-dimethyl-
propyl)-4-hydroxy-2-isopropyl-7-(4-methoxy-3-(3-methoxy-
propoxy)benzyl)-8-methylnonanamide (9g)
4.5.12. N-(3-((2S,4S,5S,7S)-5-Azido-4-hydroxy-2-isopropyl-7-
(4-methoxy-3-(3-methoxypropoxy)benzyl)-8-methylnonan-
amido)-2,2-dimethylpropyl)-4-methoxybenzamide (9k)
Starting with 8k (28 mg, 0.04 mmol), 9k (24 mg, 89%) was ob-
Starting with 8g (32 mg, 0.049 mmol), 9g (26 mg, 84.7%) was
obtained as a colorless oil: ½a D23
ꢃ
ꢂ6.9 (c 0.28, CHCl3); 1H NMR
tained as a colorless oil: ½a D23
ꢃ
ꢂ13.3 (c 0.49, CHCl3); 1H NMR
(300 MHz, CDCl3)
d
0.85–0.96 (m, 21H), 1.26–1.50 (m, 7H),
(300 MHz, CDCl3) d 0.79–0.97 (m, 18H), 1.15–1.45 (m, 3H), 1.60–
2.00 (m, 6H), 2.00–2.18 (m, 3H), 2.18–2.51 (m, 5H), 3.03–3.35
(m, 5H), 3.35 (s, 3H), 3.57 (t, J = 6.1 Hz, 2H), 3.82 (s, 3H), 3.84 (s,
3H), 4.09 (t, J = 6.6 Hz, 2H), 6.50 (br, 1H), 6.66–6.77 (m, 3H),
6.93–7.96 (m, 4H), 7.75 (br, 1H); 13C NMR (75 MHz, CDCl3) d
17.4, 20.0, 20.3, 21.3, 23.8, 29.6, 29.7, 30.4, 34.8, 35.5, 36.6, 37.8,
42.6, 45.6, 46.4, 51.3, 54.6, 55.3, 56.0, 58.6, 66.2, 69.4, 72.1,
111.8, 113.7, 114.4, 121.2, 126.8, 128.9, 134.1, 147.8, 148.3,
162.0, 167.1, 176.9; MS(ESI) m/z 672.4 [M+H]+; HRMS for
1.66–2.00 (m, 6H), 2.00–2.27 (m, 8H), 2.31 (br, 1H), 2.47 (d,
J = 6.5 Hz, 2H), 2.92–3.17 (m, 5H), 3.36 (s, 3H), 3.58 (t, J = 6.1 Hz,
2H), 3.83 (s, 3H), 4.10 (t, J = 6.5 Hz, 2H), 6.52 (br, 1H), 6.68–6.79
(m, 4H); 13C NMR (75 MHz, CDCl3) d 13.9, 17.4, 20.1, 20.3, 21.2,
22.4, 23.6, 23.8, 25.6, 29.6, 29.7, 30.4, 34.8, 35.4, 36.3, 37.0, 37.8,
42.5, 45.4, 46.2, 51.3, 54.6, 56.0, 58.7, 66.2, 69.4, 72.1, 111. 8,
114.4, 121.2, 134.2, 147.8, 148.3, 173.8, 176.7; MS(ESI) m/z 636.4
[M+H]+; HRMS for C36H65N3O6+H calcd 636..4952, found 636.4958.
C38H61N3O7+H calcd 672.4588, found 672.4593.
4.5.9. (2S,4S,5S,7S)-5-Amino-N-(2,2-dimethyl-3-(4-methyl-
phenylsulfonamido)propyl)-4-hydroxy-2-isopropyl-7-(4-
methoxy-3-(3-methoxypropoxy)benzyl)-8-methylnonanamide
(9h)
4.5.13. (2S,4S,5S,7S)-5-Amino-N-(2,2-dimethyl-3-(2-phenyl-
acetamido)propyl)-4-hydroxy-2-isopropyl-7-(4-methoxy-3-
(3-methoxypropoxy)benzyl)-8-methylnonanamide (9l)
Starting with 8l (35 mg, 0.051 mmol), 9l (31 mg, 92%) was ob-
Starting with 8h (28.8 mg, 0.044 mmol), 9h (26 mg, 93.8%) was
obtained as a colorless oil: ½a D23
ꢃ
5.1 (c 0.13, CHCl3); 1H NMR
0.73–0.94 (m, 18H), 1.15–1.45 (m, 3H),
tained as a colorless oil: ½a D23
ꢃ
ꢂ9.3 (c 0.46, CHCl3); 1H NMR
(300 MHz, CDCl3)
d
(300 MHz, CDCl3) d 0.78–0.96 (m, 18H), 1.15–1.45 (m, 3H),
1.61–1.90 (m, 5H), 2.00–2.21 (m, 5H), 2.26 (br, 1H), 2.40 (s, 3H),
2.40–2.57 (m, 3H), 2.60–2.57 (m, 3H), 2.61–2.67 (m, 1H), 2.77–
2.88 (m, 1H), 2.99 (br, 1H), 3.22–3.31 (m, 1H), 3.36 (s, 3H), 3.57
(t, J = 6.2 Hz, 2H), 3.84 (s, 3H), 4.09 (t, J = 6.5 Hz, 2H), 6.23 (br,
1H), 6.71–6.79 (m, 3H), 7.24–7.75 (m, 5H); 13C NMR (75 MHz,
CDCl3) d 17.6, 20.0, 20.2, 21.1, 21.4, 23.6, 23.8, 29.6, 29.9, 30.3,
34.8, 35.3, 35.6, 37.8, 42.6, 46.6, 50.0, 51.0, 51.3, 54.7, 56.0, 58.6,
66.2, 69.4, 71.8, 111. 9, 114.4, 121.2, 127.0, 129.5, 134.1, 142.7,
147.8, 176.9; MS(ESI) m/z 692.4 [M+H]+; HRMS for C37H61N3O7S+H
calcd 692.4308, found 692.4311.
1.60–2.20 (m, 10H), 2.34 (br, 1H), 2.48 (d, J = 6.8 Hz, 2H), 2.83–
3.13 (m, 5H), 3.36 (s, 3H), 3.57 (m, 4H), 3.83 (s, 3H), 4.10 (t,
J = 6.6 Hz, 2H), 6.57 (br, 1H), 6.65–6.79 (m, 4H), 7.27–7.33 (m,
5H); 13C NMR (75 MHz, CDCl3) d 17.4, 20.1, 20.3, 21.2, 23.5, 23.7,
27.0, 29.6, 30.4, 34.7, 35.3, 36.4, 37.8, 42.5, 44.0, 45.8, 45.9, 51.2,
54.6, 56.0, 58.6, 66.2, 69.4, 72.1, 111.8, 114.4, 121.2, 127.1, 128.8,
129.2, 134.2, 135.3, 147.8, 148.3, 171.7, 176.5; MS(ESI) m/z 656.5
[M+H]+; HRMS for C38H61N3O6+H calcd 656.4639, found 656.4643.
4.5.14. (2S,4S,5S,7S)-5-Amino-N-(2,2-dimethyl-3-(methylsulfon-
amido)propyl)-4-hydroxy-2-isopropyl-7-(4-methoxy-3-(3-
methoxypropoxy)benzyl)-8-methylnonanamide (9m)
4.5.10. Ethyl(3-((2S,4S,5S,7S)-5-amino-4-hydroxy-2-isopropyl-7-
(4-methoxy-3-(3-methoxypropoxy)benzyl)-8-methylnonan-
amido)-2,2-dimethylpropyl)carbamate (9i)
Starting with 8m (34 mg, 0.053 mmol), 9m (31 mg, 95%) was
obtained as a colorless oil: ½a D23
ꢃ
ꢂ6.0 (c 0.28, CHCl3); 1H NMR
Starting with 8i (31 mg, 0.049 mmol), 9i (26 mg, 87.5%) was ob-
(300 MHz, CDCl3) d 0.86–0.96 (m, 18H), 1.15–1.45 (m, 3H),
tained as a colorless oil: ½a D23
ꢃ
ꢂ9.3 (c 0.30, CHCl3); 1H NMR
1.60–2.00 (m, 6H), 2.00–2.20 (m, 4H), 2.28 (br, 1H), 2.39–2.56
(m, 2H), 2.86–3.21 (m, 5H), 2.89 (s, 3H), 3.36 (s, 3H), 3.58 (t,
J = 6.1 Hz, 2H), 3.83 (s, 3H), 4.10 (t, J = 6.6 Hz, 2H), 6.23 (br, 2H),
6.68–6.80 (m, 3H); 13C NMR (75 MHz, CDCl3) d 17.6, 20.0, 20.3,
21.1, 23.6, 23.7, 27.0, 29.6, 30.0, 30.5, 34.8, 35.4, 35.8, 37.9, 39.8,
42.6, 46.6, 50.0, 51.0, 54.7, 56.1, 58.6, 66.3, 69.4, 71.9, 111.9,
114.4, 121.2, 134.1, 147.8, 148.4, 177.1; MS(ESI) m/z 616.4
[M+H]+; HRMS for C31H57N3O7S+H calcd 616.3995, found
616.4003.
(300 MHz, CDCl3) d 0.85–0.96 (m, 18H), 1.23 (t, J = 7.2 Hz, 3H),
1.15–1.45 (m, 3H), 1.61–1.95 (m, 5H), 1.95–2.22 (m, 5H), 2.30
(br, 1H), 2.48 (m, 2H), 2.86–3.19 (m, 5H), 3.36 (s, 3H), 3.58 (t,
J = 6.2 Hz, 2H), 3.83 (s, 3H), 4.10 (m, 4H), 5.84 (br, 1H), 6.40 (br,
1H), 6.68–6.79 (m, 3H); 13C NMR (75 MHz, CDCl3) d 14.6, 17.4,
20.0, 20.3, 21.2, 23.4, 23.5, 29.6, 29.7, 30.4, 34.8, 35.4, 36.3, 37.8,
42.6, 46.1, 47.5, 51.3, 54.6, 56.0, 58.7, 60.7, 66.2, 69.4, 72.1, 111.
8, 114.4, 121.2, 134.2, 147.8, 148.3, 157.6, 176.4; MS(ESI) m/z
610.4 [M+H]+; HRMS for C33H59N3O7+H calcd 610.4431, found
610.4441.
4.5.15. (2S,4S,5S,7S)-5-Amino-N-(3-(ethylsulfonamido)-2,2-
dimethylpropyl)-4-hydroxy-2-isopropyl-7-(4-methoxy-3-(3-
methoxypropoxy)benzyl)-8-methylnonanamide (9n)
4.5.11. N-(3-((2S,4S,5S,7S)-5-Amino-4-hydroxy-2-isopropyl-7-(4-
methoxy-3-(3-methoxypropoxy)benzyl)-8-methylnonan-
amido)-2,2-dimethylpropyl)benzamide (9j)
Starting with 8n (35 mg, 0.053 mmol), 9n (29 mg, 86.3%) was
obtained as a colorless oil: ½a D23
ꢃ
ꢂ5.9(c 0.30, CHCl3); 1H NMR
Starting with 8j (48 mg, 0.073 mmol), 9j (43 mg, 91.3%) was ob-
(300 MHz, CDCl3) d 0.85–0.96 (m, 18H), 1.15–1.45 (m, 3H), 1.35
(t, J = 7.4 Hz, 3H), 1.55–2.00 (m, 6H), 2.00–2.17 (m, 4H), 2.25 (br,
1H), 2.50 (m, 2H), 2.70 (m, 2H), 2.90–3.23 (m, 5H), 3.36 (s, 3H),
3.58 (t, J = 6.0 Hz, 2H), 3.84 (s, 3H), 4.10 (t, J = 6.5 Hz, 2H), 6.29
(br, 2H), 6.68–6.79 (m, 3H); 13C NMR (75 MHz, CDCl3) d 8.2, 17.5,
20.0, 20.3, 21.2, 23.6, 23.7, 27.0, 29.6, 29.9, 30.5, 34.8, 35.5, 35.8,
37.9, 42.7, 46.6, 49.9, 51.0, 54.7, 56.1, 58.6, 66.3, 69.4, 72.0,
111.9, 114.4, 121.2, 134.1, 147.8, 148.4, 177.0; ESI-MS m/z 630.4
[M+H]+; HRMS for C32H59N3O7S+H calcd 630.4152, found
630.4157.
tained as a colorless oil: ½a D23
ꢃ
ꢂ11.8 (c 0.14, CHCl3); 1H NMR
(300 MHz, CDCl3)
d 0.72–1.00 (m, 18H), 1.15–1.45 (m, 3H),
1.61–2.00 (m, 6H), 2.00–2.35 (m, 5H), 2.46 (m, 2H), 2.96–3.36
(m, 5H), 3.36 (s, 3H), 3.57 (t, J = 6.1 Hz, 2H), 3.82 (s, 3H), 4.09 (t,
J = 6.6 Hz, 2H), 6.51 (br, 1H), 6.66–6.77 (m, 3H), 7.45–7.96 (m,
6H); 13C NMR (75 MHz, CDCl3) d 17.4, 20.0, 20.3, 21.3, 23.8, 27.0,
29.6, 29.7, 30.4, 34.8, 35.5, 36.7, 37.8, 42.6, 45.6, 46.4, 51.3, 54.6,
56.0, 58.6, 66.2, 69.4, 72.1, 111.8, 114.3, 121.2, 127.1, 128.5,
131.2, 134.1, 134.5, 147.7, 148.3, 167.5, 177.0; MS(ESI) m/z

Y. Wu et al. / Bioorg. Med. Chem. 19 (2011) 4238–4249
4249
4.5.16. (2S,4S,5S,7S)-5-Amino-N-(3-(3,3-dimethylureido)-2,2-
dimethylpropyl)-4-hydroxy-2-isopropyl-7-(4-methoxy-3-(3-
methoxypropoxy)benzyl)-8-methylnonanamide (9o)
no more than 30 s. Fluorescence intensity was immediately mea-
sured at Ex/Em = 330 nm/390 nm and the data were recorded con-
tinuously (each minute) for 15 min.
Starting with 8o (28 mg, 0.044 mmol), 9o (24 mg, 89.6%) was
obtained as a colorless oil: ½a D23
ꢃ
ꢂ14.7 (c 0.32, CHCl3); 1H NMR
4.7. Molecular docking
(300 MHz, CDCl3)
d 0.83–0.96 (m, 18H), 1.15–1.45 (m, 3H),
1.60–2.00 (m, 6H), 2.00–2.20 (m, 4H), 2.44 (br, 1H), 2.47 (d,
J = 6.8 Hz, 2H), 2.93 (s, 6H), 2.90–3.20 (m, 5H), 3.36 (s, 3H), 3.58
(t, J = 6.1 Hz, 2H), 3.83 (s, 3H), 4.10 (t, J = 6.5 Hz, 2H), 5.59 (br,
2H), 6.68–6.82 (m, 4H); 13C NMR (75 MHz, CDCl3) d 17.4, 20.1,
20.3, 21.3, 23.6, 23.8, 27.0, 29.6, 30.3, 34.7, 35.4, 35.8, 36.0, 36.3,
37.8, 42.5, 45.8, 46.9, 51.4, 54.5, 56.1, 58.6, 66.2, 69.4, 72.2,
111.9, 114.4, 121.2, 134.2, 147.7, 148.3, 159.0, 176.5; MS(ESI) m/z
609.5 [M+H]+; HRMS for C33H60N4O6+H calcd 609.4591, found
609.4603.
The protein structure of renin used in the docking studies was
obtained from the protein data bank with the code 2v0z. All hydro-
gen atoms were added, and an active site of a sphere was set
around the internal ligand. Then the internal inhibitor and water
molecules were removed. All the eighteen novel ligands and aliski-
ren were drawn and all hydrogen atoms were added. Incorrect
atom type was modified, and the structures were energy mini-
mized using ‘Steepest Descent’, ‘Conjugated Gradient’ and ‘Powell
algorithms’ method subsequently with a convergence gradient va-
lue of 0.001 kcal/(mol Å), 1000 max iterations, saved as mol2 for-
mat using SYBYL 6.9 package.
Molecular docking was performed using software of GOLD that
applied genetic algorithm. The number of generic algorithm runs
was set to 20. Define the active site using a sphere (point:
32.129, 14.886, 87.994; radius: 13 Å). Other parameters were the
default.
4.5.17. (2S,4S,5S,7S)-5-Amino-N-(2,2-dimethyl-3-(sulfamoyl-
amino)propyl)-4-hydroxy-2-isopropyl-7-(4-methoxy-3-(3-
methoxypropoxy)benzyl)-8-methylnonanamide (9p)
Starting with 8p (34 mg, 0.053 mmol), 9p (29 mg, 89%) was ob-
tained as a colorless oil: ½a D23
ꢃ
ꢂ5.8 (c 0.21, CHCl3); 1H NMR
(300 MHz, CDCl3)
d 0.85–0.95 (m, 18H), 1.15–1.45 (m, 3H),
1.55–2.00 (m, 5H), 2.00–2.15 (m, 3H), 2.30 (br, 1H), 2.38–2.59
(m, 2H), 2.80 (br, 2H), 2.95–3.25 (m, 6H), 3.36 (s, 3H), 3.36 (br,
1H), 3.57 (t, J = 6.1 Hz, 2H), 3.83 (s, 3H), 4.10 (t, J = 6.5 Hz, 2H),
6.26 (br, 1H), 6.68–6.80 (m, 3H), 7.69 (s, 1H), 7.76 (s, 1H); 13C
NMR (75 MHz, CDCl3) d 17.8, 19.8, 20.3, 21.1, 23.7, 23.9, 29.6,
30.0, 30.6, 34.3, 35.2, 35.4, 37.8, 42.8, 46.6, 50.4, 51.1, 54.5, 56.1,
58.6, 66.3, 69.4, 72.2, 111.9, 114.6, 121.3, 134.2, 147.8, 148.3,
176.8; MS(ESI) m/z 617.4 [M+H]+; HRMS for C30H56N4O7S+H calcd
617.3948, found 617.3956.
Acknowledgments
This work was supported by the ‘111 Project’ from the Ministry
of Education of China and the State Administration of Foreign Ex-
pert Affairs of China (No. 111-2-07).
References and notes
4.5.18. (2S,4S,5S,7S)-5-Amino-N-(2,2-dimethyl-3-(1H-1,2,3-
triazol-1-yl)propyl)-4-hydroxy-2-isopropyl-7-(4-methoxy-3-
(3-methoxypropoxy)benzyl)-8-methylnonanamide (29r)
Starting with 8r (28 mg, 0.045 mmol), 9r (25 mg, 93.3%) was
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The Sensolyte 390 Renin assay kit was used to determine the
activity and IC50 values of 19 compounds against renin enzyme.
Each of the test compounds in DMSO was diluted at 6 different
concentrations of 500, 100, 20, 4, 0.8 and 0.16 nM in assay buffer
(pH 7.4). The renin substrate was diluted 1:100 in assay buffer be-
fore test. To set up enzymatic reaction, the test compounds and re-
nin solution were added into the microplate wells. Each well of a
384-well plate contained 28 lL of renin solution and 5 lL of test
compound. The vehicle control contained diluted renin and diluted
vehicle DMSO. The plate was incubated at 37 °C for 30 min, and at
the same time, the renin substrate solution was incubated at 37 °C.
To each well was added 17
lL of renin substrate solution. All the
reagents were mixed completely by shaking the plate gently for