Synthesis of SHIP1-activating analogs of the sponge meroterpenoid pelorol

Article abstract of DOI:10.1002/ejoc.201200631

Two biomimetic approaches have been used to synthesize analogs of the SHIP1-activating sponge meroterpenoid pelorol (1). One approach started from the chiral pool plant natural product sclareolide, which has the same absolute configuration as pelorol. The

Full text of DOI:10.1002/ejoc.201200631

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FULL PAPER
DOI: 10.1002/ejoc.201200631
Synthesis of SHIP1-Activating Analogs of the Sponge Meroterpenoid Pelorol
Labros G. Meimetis,[a][‡] Matt Nodwell,[a][‡] Lu Yang,[a] Xiaoxia Wang,[a] Joyce Wu,[b]
Curtis Harwig,[b] Grant R. Stenton,[b] Lloyd F. Mackenzie,[b] Thomas MacRury,[b]
Brian O. Patrick,[a] Andrew Ming-Lum,[c] Christopher J. Ong,[c] Gerald Krystal,[d]
Alice L. -F. Mui,[c] and Raymond J. Andersen*[a]
Dedicated to the memory of Ernesto Fattorusso
Keywords: Natural products / Medicinal chemistry / Biomimetic synthesis / Enzymes / Terpenoids / Enantioselectivity
Two biomimetic approaches have been used to synthesize
analogs of the SHIP1-activating sponge meroterpenoid pelo-
rol (1). One approach started from the chiral pool plant natu-
ral product sclareolide, which has the same absolute configu-
finement led to the resorcinol analog 18, which is the most
effective SHIP1-activating pelorol analog made to date. The
HCl salt of ent-28, a C-3 amino analog of 18, is about
500,000-fold more soluble in water than MN100 (3). (Ϯ)-
ration as pelorol. The second approach utilized an enantiose- 28·HCl activates SHIP1 in vitro, inhibits Akt phosphorylation
lective polyene cyclization to efficiently access both absolute
configurations of the pelorol meroterpenoid skeleton and to
prepare A-ring functionalized compounds. Selected analogs
have been evaluated for water solubility and biological ac-
tivity. It was found that the undesirable catechol and ester
functionalities in 1 could be removed to give MN100 (3),
without a decrease in SHIP1-activating ability. A further re-
in stimulated MOLT-4 (SHIP+) cells, and is active in a dose-
dependent manner in a mouse model of inflammation when
administered by oral gavage (ED50 ≈ 0.1 mg/kg). Pelorol ana-
logs ent-28 or (Ϯ)-28 are promising chemical tools for further
preclinical in vivo evaluation of the potential of SHIP1 acti-
vators as therapeutics for treating hematopoietic diseases in-
volving aberrant activation of PI3K cell signaling.
acting with pleckstrin homology (PH) domain-containing
proteins such as protein kinase B (PKB, also known as
Akt), which becomes phosphorylated during active signal-
ing. The levels of PIP3 in unstimulated cells is very low,
but it is rapidly synthesized from PI-4,5-P2 in response to
extracellular stimuli. To ensure that activation of the PI3K
pathway is appropriately restrained under normal circum-
stances, the tumor suppressor phosphatase and tensin
homolog (PTEN) hydrolyzes PIP3 back to PI-4,5-P2 and
the Src homology 2-containing inositol 5-phosphatases
(SHIP1, sSHIP, and SHIP2) hydrolyze it to phosphatidyl-
inositol-3,4-bisphosphate (PI-3,4-P2), events that in both
cases reduce the levels of the second messenger PIP3 and
dampen the signal.
PI3K signaling is aberrantly activated in many human
cancers and inflammatory diseases.[2] It has been estimated
that mutation of PI3K pathway components such as PTEN
accounts for up to 50% of all human cancers. As a conse-
quence, drugs targeting the PI3K signaling pathway are be-
ing actively developed.[3] These drugs are designed to pre-
vent the formation of the second messenger PIP3 by in-
hibiting PI3K itself or by blocking signal transmission by
inhibiting protein kinases downstream in the pathway.
We recently proposed that an attractive alternative ap-
proach to modulating aberrant PI3K signaling would be
Introduction
The activation of phosphoinositide 3-kinase (PI3K) is
stimulated by highly specific binding interactions between a
variety of extracellular ligands and their membrane bound
receptors and leads to initiation of signal transduction cas-
cades that enhance cellular activation, proliferation, and/or
survival depending on the cell type and external stimu-
lus.[1,2] PI3K phosphorylates phosphatidylinositol-4,5-bis-
phosphate (PI-4,5-P2) to generate the important second
messenger phosphatidylinositol-3,4,5-trisphosphate (PI-
3,4,5-P3, or more commonly PIP3) in the plasma mem-
brane. PIP3 then mediates downstream signaling by inter-
[a] Departments of Chemistry and Earth, Ocean & Atmospheric
Sciences, University of British Columbia,
2036 Main Mall, Vancouver, B.C. V6T 1Z1, Canada
Fax: +1-604-822 6091
E-mail: Raymond.andersen@ubc.ca
[b] Aquinox Pharmaceuticals Inc.,
Suite 430-5600 Parkwood Way, Richmond, B.C. V6V 2M2,
Canada
[c] Department of Surgery, University of British Columbia,
Vancouver, B.C. V5Z 1L3, Canada
[d] Terry Fox Laboratory, B.C. Cancer Control Agency,
Vancouver, B.C. V5Z 1L3, Canada
[‡] These authors contributed equally to the research.
Supporting information for this article is available on the
WWW under http://dx.doi.org/10.1002/ejoc.201200631.
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to activate the phosphatase SHIP1.[4] The hematopoietic- candidates or biological tools. First, the catechol function-
restricted expression of SHIP1 should limit the effects of a ality in 1 and 2 could undergo either chemical or enzymatic
highly selective SHIP1 agonist to target cells. Furthermore, oxidation to orthoquinones that could form covalent link-
activation of a phosphatase is expected to occur through an ages with proteins by non-selective Michael addition reac-
allosteric binding interaction of the agonist rather than by tions leading to off target biological effects. Second, both 1
competitive binding at the active site. The major challenge and 2 are highly insoluble in water, which severely limits
in developing selective kinase inhibitors, which are pre- their administration to animals and, therefore, their useful-
dominately competitive with ATP binding, is the high de- ness as tools to explore the full range of in vivo biological
gree of homology at kinase active sites.[4] A high degree of properties of a SHIP1 activator.
homology between allosteric activation sites on phospha-
tases is not expected and, therefore, the goal of much higher biomimetic synthetic routes to pelorol analogs in order to
target selectivity should be easier to achieve. find compounds with increased SHIP1 activation abilities
In order to address these issues, we have developed two
In order to find a first-generation SHIP1 activator for a and enhanced water solubility. The first route, which starts
proof-of-principle (POP) test of our target hypothesis, we with the plant natural product sclareolide to establish the
used a chromogenic kinetic assay that monitors SHIP1 absolute configuration of analogs, was used in our reported
phosphatase activity to screen a library of crude extracts synthesis of the natural product pelorol (1) and the simpli-
prepared from marine invertebrates. This screen identified fied analog 16A (2).[5] The second route utilizes a newly
the meroterpenoid pelorol (1), isolated from the sponge developed enantioselective polyene cyclization approach to
Dactylospongia elegans collected in Papua New Guinea, as make both absolute configurations of the pelorol meroter-
a selective and relatively potent SHIP1 activator.[5] We com- penoid skeleton and to add polar water-solubilizing func-
pleted a total synthesis of pelorol in order to confirm the tionalities to the A ring. Details of the application of these
absolute configuration of the natural product and to pro- approaches to the synthesis of pelorol analogs are presented
vide more compound for biological evaluation. The initial below.
synthesis also generated a small number of analogs for pre-
liminary SAR. One of the analogs, designated 16A (2), in
which the C-20 methyl ester substituent in pelorol had been
Results and Discussion
replaced by a methyl group, was more readily synthesized
First we focused our attention on making 16A (2) ana-
than pelorol (1) and also showed more potent SHIP1 acti-
logs that did not possess the catechol functionality. Two
vation than the natural product.[5]
possible target molecules were the C-17 and C-18 mono-
phenolic analogs 3 and 4. Based on literature precedent and
our own experience in the pelorol synthesis,[5] it was antici-
pated that a phenyl ring activated by a strongly electron
donating OMe substituent ortho or para to the C-21 carbon
where the new alkyl bond would form would be required
for successful biomimetic cation-initiated cyclization (see
Scheme 1, 9 to 10) to give the five membered ring C of
16A analogs. Therefore, the monophenolic 16A analog 3,
designated MN100, was chosen as the initial target.
The target specificity and biological efficacy of 16A (2)
was evaluated by comparing its effects on PI3K-regulated
processes in primary SHIP1+/+ vs. SHIP1–/– murine ma-
crophages and mast cells.[3] Data generated in these experi-
ments were consistent with 16A (2) inhibiting PI3K-de-
pendent macrophage and mast-cell responses in a SHIP1-
dependent manner. 16A (2) was also tested for its efficacy
at inhibiting inflammatory reactions in vivo by assessing its
ability to provide protection in mouse models.[3] As pre-
The synthesis of MN100 (3) started from the 8-hydroxy-
dicted for an activator of SHIP1, 16A (2) reduced the levels 11-drimanal intermediate 5 prepared from sclareolide as de-
of serum TNF-α in a mouse model of endotoxic shock and scribed in our pelorol synthesis (Scheme 1).[5] Reaction of 5
topically applied 16A (2) inhibited allergen-induced inflam- with the phenyllithium reagent prepared from commercially
mation in a standard mouse ear edema/cutaneous anaphy- available 3-bromo-5-methylanisole (6), gave a mixture of the
laxis model. The biological profile of 16A (2) in the cell- epimeric benzylic alcohols 7. Attempts to remove the C-11
based assays and mouse models provided a convincing POP benzylic alcohol from 7 by hydrogenolysis using Pd and Pt
demonstration that SHIP1 activators should be viable drug catalysts produced only small amounts of desired product
candidates for treating inflammatory diseases and it indi- 9, even under conditions of very high hydrogen pressure
cated that pelorol (1) and 16A (2) were promising lead and long reaction times. Therefore, the benzylic alcohol was
structures for developing such a drug candidate.
removed using the standard Barton-McCombie deoxygen-
Although the biological activities of 1 and 2 were promis- ation sequence.[6] Treatment of diastereomeric mixture 7
ing, these compounds have two liabilities as potential drug with sodium hydride and carbon disulfide in THF and then
2
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SHIP1-Activating Analogs of the Sponge Meroterpenoid Pelorol
Scheme 1. Synthetic route to MN100 (3) and resorcinol 18 starting from sclareolide.
with methyl iodide gave the diastereomeric mixture of ated cyclization step (16 to 17, Scheme 1) in its synthesis.
methyl xanthates 8 in high yield. Reaction of xanthates 8
with tributyltin hydride and AIBN in refluxing toluene
cleanly gave deoxygenated intermediate 9. Cyclization of 9
using tin tetrachloride in dichloromethane gave tetracyclic
product 10 as the major product, along with a small
amount of regiosiomer 11, in nearly quantitative yield.[7]
Demethylation of 10 using BBr3 cleanly generated MN100
(3), the desired monophenolic analog of 16A (2). MN100
(3) turned out to be a more effective SHIP1 activator than
16A (2),[3] but suffered from very low solubility in water
(Table 1).
The synthesis of 18 started with the dimethoxybromo-
benzene 12 and followed the route to MN100 (3) as out-
lined in Scheme 1. Resorcinol 18 was about 300-fold more
water soluble than MN100 (3) (Table 1) and it was a more
effective in vitro activator of SHIP1 than MN100 (3)
(Table 2). Therefore, compound 18 became the core tem-
plate for the design of further CLogP-reduced analogs.
In an attempt to produce analogs of 18 with even lower
CLogP values, we next explored A-ring functionalized com-
pounds. Extensive unpublished SAR from our lab had
shown that the aromatic ring was a critical part of the pelo-
rol SHIP1-activating pharmacophore. Hence, we decided to
add water solubilizing functionality to the A-ring of 18 in
order to have minimal impact on the aromatic binding site.
The 3-amino derivative 28 was of particular interest because
the neutral form has a CLogP of 3.58, well within the drug-
like range. In addition, the amino group should be proton-
ated at physiological pH and the resulting ammonium ion
salt would be expected to have increased water solubility.
The synthetic route to 28 outlined in Scheme 2 featured
a cation-initiated polyene cyclization to generate the tetra-
cyclic ring system. Lithiation of 3,5-dimethoxybromobenz-
ene (12) followed by alkylation with farnesyl bromide (19)
gave the prenylated 3,5-dimethoxybenzene intermediate 20
in moderate yield.[10] Initially, racemic epoxide (Ϯ)-22 was
formed from 20 using meta-chloroperbenzoic acid (not
shown) and the remaining steps in the synthesis (Scheme 2)
were explored using racemic intermediates to give racemic
(Ϯ)-(28) product.
Table 1. Water or buffer solubilities of selected pelorol analogs.
Solubility in water
Solubility in Tris buffer
[μg/mL]
[μg/mL]
MN100 (3)
18
ent-28·HCl
–
–
0.003
0.92
–
1,400
Lipinski’s Rules are a commonly used guide to assess the
drug-like properties of molecules.[8] One of the important
criteria that a drug-like substance must meet under these
rules is having a CLogP of less than 5. CLogP is a measure
of the lipophilicity of the molecule and it is a good predic-
tor of oral bioavailability and water solubility.[9] Pelorol (1),
the lead compound in this SHIP1-activating series has a
CLogP of 5.74, outside of the acceptable Lipinski range.
Similarly, 16A (2) (CLogP 5.57) and MN100 (3) (CLogP
6.16) are too lipophilic to be drug-like. As a first step in
Subsequently, an enantioselective Shi epoxidation of 20
decreasing the CLogP and increasing the water solubility of with the ent-Shi catalyst 21 was used to generate the S ter-
pelorol analogs, we made the resorcinol derivative 18, which minal epoxide 22 and the following steps in the synthesis
has a CLogP of 4.99 and provides the synthetic advantage were optimized starting with this single enantiomer inter-
that no regioisomers should be formed in the cation initi- mediate.[11] Treatment of epoxide 22 with InBr3 initiated the
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Table 2. Activation of His-hSHIP1 enzyme. Percent (%) activation
is expressed as a percentage increase relative to background. Scor-
ing is expressed as follows: + (Ͻ 25%); ++ (Ն 25% but Ͻ 50%);
+++ (Ն 50%).
Scheme 2. Polyene cyclization route to pelorol analogs.
Dess–Martin oxidation of the C-3 secondary alcohol in
23 gave ketone 26 (Scheme 2). Removal of the methyl ether
protecting groups in 26 with BBr3 generated resorcinol in-
termediate 27. Reductive amination of 27 gave desired 3β-
amino analog 28 as the major product along with a small
amount of 3α-amino product 29.[14] Repeating the synthesis
with the Shi catalyst that is the enantiomer of 21[11] gave
3β-amino analog ent-28 and 3α-amino analog ent-29.[15]
polyene cyclization to give the desired tetracyclic intermedi-
ate 23.[12,13] The ee (94%) for the combined epoxidation and
cyclization steps was determined by analyzing the ratio of
Mosher esters 24 and 25 formed from reaction of 23 with
(R)-α-methoxy-α-trifluoromethylphenylacetyl chloride [(R)-
MTPA-Cl] (Scheme 2). One recrystallization of alcohol 23
gave material that was Ͼ 99.5% of the single enantiomer
shown. The absolute configuration of 23 was confirmed by
The epoxidation of 20 (Scheme 2) gave a low yield (28%)
single-crystal X-ray diffraction analysis (Supporting Infor- of desired terminal epoxide 22, that could only be obtained
mation).
as a single compound after a challenging chromatography
4
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SHIP1-Activating Analogs of the Sponge Meroterpenoid Pelorol
Scheme 3. Improved route to epoxide intermediate 22.
step. In order to improve this part of the synthesis of amino
The synthesis of 18 from sclareolide gave the resorcinol
analog 28, an alternate synthesis of epoxide 22 was devel- analog with the same absolute configuration as pelorol.
oped as shown in Scheme 3. Lithiation of bromobenzene 12 Starting with compound 38, the intermediate in the polyene
followed by alkylation with dimethylallyl bromide (30) gave cyclization route to amino derivative ent-28, we carried out
the prenylated resorcinol derivative 31. Selenium dioxide a Barton–McCombie deoxygenation to give 39 followed by
oxidation of the prenyl substituent in 31 gave E allylic removal of the methyl ether protecting groups to give ent-
alcohol 32,[16] that was converted into corresponding E all- 18, so that we could assess the role of absolute configura-
ylic bromide 33 using Appel reaction conditions.[17]
Reaction of geranyl bromide (34) with tetrabutylammo-
nium iodide and sodium p-tolunesulfinate gave allylic sulf-
one 35 in quantitative yield (Scheme 3).[18] Shi epoxidation
of 35 gave terminal epoxide 36 enantio- and regioselectively
in high chemical yield. Deprotonation of allylic sulfone 36
with potassium tert-butoxide followed by alkylation with
allylic bromide 33 afforded epoxide 37 in nearly quantita-
tive yield.[19] Palladium catalyzed reductive elimination of
tosyl sulfone moiety in 37 gave desired epoxide 22 in good
yield.[20] This convergent synthesis of critical epoxide inter-
mediate 22 proceeded in 59% overall though 4 linear steps
from the readily available starting material geranyl bromide
(34) without any difficult chromatography steps (Scheme 3),
a significant improvement over the direct epoxidation of 20
(Scheme 2).
tion on SHIP1 activation (Scheme 4).
Scheme 4. Synthesis of ent-18.
One major objective of the synthetic program described
above was to prepare pelorol analogs with CLogP values in
the Lipinksi-range for drug-like molecules in order to gen-
erate enhanced water solubilities. Table 1 gives the solubilit-
Reaction of the ketone 27 (Scheme 2) with hydroxyl-
ies of MN100 (3), resorcinol analog 18, and the HCl salt of amine afforded oxime 40 (Scheme 5). Beckmann rearrange-
ent-28 either in pure water or Tris buffer. As anticipated, ment of 40 gave ring expanded lactam 41 as the major prod-
there was a significant ca. 500,000 fold increase in water/ uct, and LAH reduction of 41 gave A-ring azepine analog
buffer solubility in going from MN100 (3) to ent-28·HCl.
42. The synthesis of 27, 40, 41, and 42 illustrates a small
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sampling of the wide variety of A-ring functionalized ana- stimulated with IGF1 but not in SHIP1(–) Jurkat cells, con-
logs that can be easily accessed as either enantiomer by the sistent with SHIP1 activation in whole cells (Supporting In-
polyene cyclization route.
formation, Figure S61). The same racemic (Ϯ)-28·HCl mix-
ture was also evaluated in a standard mouse passive cutane-
ous anaphylaxis ear model of inflammation.[22] When ad-
ministered by oral gavage, (Ϯ)-28·HCl showed effective
anti-inflammatory activity with a clear dose response and
an ED50 of about 0.1 mg/kg (Figure 1).
Scheme 5. Synthesis of A ring functionalized analogs of pelorol.
Biological Activity of Pelorol Analogs
Figure 1. Efficacy of (Ϯ)-28·HCl or cyproheptadine (Cyp, 1 mg/
kg) in a mouse passive cutaneous anaphylaxis (PCA) model. PCA
response results in the extravasation of Evans Blue in the ears of
mice. Evans Blue was extracted by dimethyl formamide and data
are presented as the optical density. Data represent meanϮSEM
(n = 10), *p Ͻ 0.05 shows the effect of (Ϯ)-28·HCl or of cyprohep-
tadine, compared to the response of the vehicle-treated control ani-
mals.
Only selected synthetic analogs have been tested for bio-
logical activity thus far. The analog MN100 (3), in which
the undesirable catechol functionality found in pelorol (1)
and 16A (2) has been removed by replacing the C-17 phenol
functionality with a hydrogen atom, was found to be a
slightly more effective SHIP1 activator than 16A.[3] We have
used MN100 (3) to provide further in vitro and in vivo POP
demonstrations of the drug potential of SHIP1 activators
in this family and to demonstrate that pelorol analogs bind
to the C-2 allosteric activation domain of SHIP1.[3,21]
Even though MN100 (3) showed good activity in the in
Conclusions
Two biomimetic synthetic routes have been developed for
vitro and in vivo mouse model experiments, its large CLogP the preparation of analogs of the SHIP1-activating sponge
and very low water solubility made it an unlikely drug can- meroterpenoid pelorol (1). Both routes are efficient and give
didate and a poor chemical tool for exploring the thera- products with high ee. They have facilitated the preparation
peutic potential of SHIP1 activators in other mouse models. of structurally diverse analogs on Ͼ 100 mg scales useful
The next step in the progression of pelorol analogs towards for further exploration of the SAR and in vivo biological
drug-like molecules was the synthesis of the resorcinol-con- activities of this new pharmacophore. The results described
taining analog 18, which had a lower CLogP and was more above successfully address the major challenge of providing
efficient to synthesize than MN100 (3) because it produced an effective renewable supply of a sponge natural product
no regioisomers in the cation initiated cyclization step. As or more drug-like pharmacophore analogs for preclinical
shown in Table 1, 18 was a more effective in vitro activator biological evaluation.
of SHIP1 than MN100 (3) and it became the reference stan-
Amino derivative ent-28·HCl, one of the new synthetic
dard for the evaluation of further CLogP-reduced analogs. pelorol (1) analogs prepared in this work, had significantly
Interestingly, 18 and ent-18 showed nearly identical SHIP1- enhanced water solubility compared with the natural prod-
activating properties, suggesting that the absolute configu- uct and other SHIP1-activating analogs such as MN100 (3).
ration of the meroterpenoid skeleton was not crucial for Pure ent-28·HCl and racemate (Ϯ)-28·HCl both activated
this analog.
SHIP1 in vitro (Table 2) and racemate (Ϯ)-28·HCl was
Racemic A-ring α and β 3-amino analogs (Ϯ)-29·HCl found to inhibit the phosphorylation of Akt in a manner
and (Ϯ)-28·HCl were both in vitro SHIP1 activators, but consistent with SHIP1 activation in whole cells (Supporting
neither was as effective as the reference compound 18 Information, Figure S61). The same racemic mixture (Ϯ)-
(Table 1). Analog 28·HCl was somewhat less active than ra- 28·HCl showed potent in vivo anti-inflammatory activity
cemic (Ϯ)-28·HCl, whereas ent-28·HCl had identical (ED50 of ca. 0.1 mg/kg) in a mouse model with a clear dose-
SHIP1-activating ability in comparison with the racemic response when administered by oral gavage (Figure 1). The
mixture, indicating that in the 3-amino series the absolute facile synthetic accessibility of either ent-28·HCl or race-
configuration was important. Racemate (Ϯ)-28·HCl in- mate (Ϯ)-28·HCl, combined with their enhanced water sol-
hibited the phosphorylation of Akt in SHIP(+) Molt-4 cells ubility and SHIP1-activating properties, makes them at-
6
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SHIP1-Activating Analogs of the Sponge Meroterpenoid Pelorol
raphy (hexanes/EtOAc) for characterization; however, this product
mixture could be used in the next step without further purification.
8: H NMR (400 MHz, CDCl3, 25 °C): δ = 6.8 (s, 1 H), 6.7 (s, 1
tractive chemical tools for the further preclinical in vivo
evaluation of the hypothesis that activating SHIP1 is a via-
ble approach to treating blood diseases caused by aberrant
activation of PI3K cell signaling.
1
H), 6.5 (s, 1 H), 5.18 (d, J = 5.2 Hz, 1 H), 3.75 (s, 3 H), 2.38 (s, 3
H), 2.28 (s, 3 H), 2.18 (d, J = 5.2 Hz, 1 H), 1.81 (m, 1 H), 1.78 (m,
1 H), 1.75 (m, 1 H), 1.65 (m, 1 H), 1.55 (m, 1 H), 1.50 (s, 3 H),
1.45 (m, 1 H), 1.34 (m, 1 H), 1.31 (m, 1 H), 1.28 (m, 1 H), 1.02 (s,
3 H), 0.99 (dt, J = 13.6, 3.8 Hz, 1 H), 0.87 (dd, J = 12.2, 2.4 Hz, 1
H), 0.80 (s, 3 H), 0.77 (s, 3 H), 0.56 (td, J = 12.9, 3.5 Hz, 1 H) ppm.
13C NMR (100 MHz, CDCl3, 25 °C): δ = 189.7, 159.4, 149.9, 139.5,
120.9, 112.3, 110.9, 74.2, 65.1, 55.9, 55.0, 46.8, 46.0, 41.3, 41.0,
40.2, 33.30, 33.26, 26.3, 21.6, 21.3, 20.2, 18.3, 15.9, 13.0 ppm.
HRESIMS [M + Na]+ calcd. for C25H38O3S2Na 473.2160, found
473.2159.
Experimental Section
General Experimental Procedures: Optical rotations were measured
with a Jasco -1010 polarimeter with sodium light (589 nm) in
1
EtOAc. The H and 13C NMR spectra were recorded with either a
Bruker AV-400 spectrometer or a Bruker AV-600 spectrometer with
a 5 mm CPTCI cryoprobe. 1H chemical shifts are referenced to the
residual CDCl3, CD2Cl2, (CD3)2CO, and CD3OD signals (d 7.24,
5.32, 2.05, 3.31 ppm, respectively) and 13C chemical shifts are refer-
enced to the CDCl3, CD2Cl2, (CD3)2CO, and CD3OD signals (d
77.0, 54.0, 29.9, 49.1 ppm, respectively). Low and high resolution
ESI-QIT-MS were recorded with a Bruker–Hewlett Packard 1100
Esquire–LC system mass spectrometer. Merck Type 5554 silica gel
plates and Whatman MKC18F plates were used for analytical thin
layer chromatography. Flash chromatography was carried out on
Silicycle SiliaFlash 60A. Reversed-phase HPLC analyses of purity
were performed on a C-18 column on a Waters 600E System Con-
troller liquid chromatography attached to a Waters 996 Photodiode
Array Detector. All solvents used for HPLC were Fisher HPLC
grade. All final compounds tested for biological activity had a pu-
rity of Ͼ 95% as assessed by HPLC.
Preparation of 9: The crude mixture of xanthate 8 was dissolved in
toluene (50 mL). Bu3SnH (2.9 mL, 10.8 mmol) was added, and the
solution was heated. Once at reflux, a catalytic amount of AIBN
(50 mg, 8.21 mmol) was added through the top of the condenser.
The solution was refluxed for 1 h, and then an additional amount
of AIBN was added (50 mg, 8.21 mmol). The solution was refluxed
for another 45 min, after which TLC analysis indicated the reaction
to be complete. The reaction was cooled, and then concentrated
to dryness. Flash chromatography (hexanes/EtOAc) of the crude
product yielded alcohol 9 (1.12 g, 3.23 mmol, 60%, 2 steps) as a
1
white foam. 24: H NMR (400 MHz, CDCl3, 25 °C): δ = 6.68 (s, 1
H), 6.63 (s, 1 H), 6.49 (s, 1 H), 3.75 (s, 3 H), 2.70 (dd, J = 14.7,
5.9 Hz, 1 H), 2.60 (dd, J = 14.7, 4.5 Hz, 1 H), 2.27 (s, 3 H), 1.84
(dt, J = 12.4, 3.1 Hz, 1 H), 1.70 (m, 1 H), 1.64 (m, 1 H), 1.54 (m,
1 H), 1.43 (m, 1 H), 1.39 (m, 1 H), 1.35 (m, 1 H), 1.31 (m, 1 H),
1.25 (s, 3 H), 1.09 (td, J = 13.3, 3.9 Hz, 1 H), 0.96 (m, 1 H), 0.93
(m, 1 H), 0.90 (m, 1 H), 0.87 (s, 3 H), 0.85 (s, 3 H), 0.78 (s, 3
H) ppm. 13C NMR (100 MHz, CDCl3, 25 °C): δ = 159.5, 145.9,
139.2, 122.1, 111.9, 111.3, 74.1, 63.0, 56.0, 55.0, 44.0, 41.7, 40.3,
39.1, 33.3, 33.2, 31.2, 24.5, 21.5, 21.4, 20.2, 18.4, 15.4 ppm. HRES-
IMS [M + Na]+ calcd. for C23H36O2Na 367.2613, found 367.2615.
Preparation of 7: To 1-bromo-3-methoxy-5-methylbenzene (6)
(3.64 g, 18.29 mmol) dissolved in THF (35 mL), and cooled to
–78 °C, was added 1.7 m tBuLi (21.5 mL, 36.6 mmol). The solution
was stirred for 10 min at –78 °C, and then warmed to room temp.
for 20 min. The solution was again brought to –78 °C, and a solu-
tion of aldehyde 5 (1.45 g, 6.09 mmol) in THF (6 mL) was added.
The solution was stirred at –78 °C for 2 h, and then the reaction
was quenched by addition of 1 m HCl (5 mL). EtOAc (100 mL) was
added, and the organic phase was washed with 1 m HCl (25 mL),
followed by saturated NaHCO3 (50 mL). The organic phase was
dried with MgSO4, filtered and concentrated. The crude reaction
mixture was purified by flash chromatography (hexanes/EtOAc) to
yield diol 7 (1.94 g, 5.39 mmol, 88%). 1H NMR (400 MHz, CDCl3,
25 °C): δ = 6.85 (s, 1 H), 6.78 (s, 1 H), 6.61 (s, 1 H), 4.79 (d, J =
8.1 Hz, 1 H), 3.79 (s, 3 H), 2.33 (s, 3 H), 2.12 (d, J = 8.1 Hz, 1 H),
1.84 (dt, J = 12.2, 3.3 Hz, 1 H), 1.63 (m, 1 H), 1.56 (m, 1 H), 1.54
(s, 3 H), 1.40 (m, 1 H), 1.33 (m, 1 H), 1.23 (m, 1 H), 1.16 (m, 1
H), 1.13 (m, 1 H), 1.02 (s, 3 H), 0.97 (td, J = 13.5, 3.6 Hz, 1 H),
0.90 (m, 1 H), 0.82 (s, 3 H), 0.77 (s, 3 H), 0.34 (td, J = 13.3, 3.6 Hz,
1 H) ppm. 13C NMR (100 MHz, CDCl3, 25 °C): δ = 159.7, 149.0,
139.8, 120.7, 113.6, 110.5, 76.0, 62.85, 62.84, 55.8, 55.1, 44.0, 41.3,
40.8, 38.6, 33.5, 33.2, 26.1, 21.53, 21.50, 19.8, 18.3, 15.9 ppm.
HRESIMS [M + Na]+ calcd. for C23H36O3Na 383.2562, found
383.2563.
Preparation of 10: Alcohol 9 (1.12 g, 3.23 mmol) was dissolved in
CH2Cl2 (10 mL) and cooled to 0 °C. To this solution was added
neat SnCl4 (1 mL, 8.5 mmol). The orange solution was then stirred
for 1 h at 0 °C, followed by quenching with MeOH (1 mL). The
reaction was diluted with EtOAc (200 mL), and washed with satu-
rated NaHCO3 (50 mL). The organic phase was dried with MgSO4,
filtered and concentrated. The crude was purified by flash
chromatography to yield tetracycle 10 (1.05 g, 3.20 mmol, 99%).
1
10: H NMR (400 MHz, CDCl3, 25 °C): δ = 6.62 (s, 1 H), 6.41 (s,
1 H), 3.74 (s, 3 H), 2.60 (m, 1 H), 2.49 (dd, J = 14.5, 6.2 Hz, 1 H),
2.34 (m, 1 H), 2.27 (s, 3 H), 1.71 (m, 4 H), 1.54 (m, 2 H), 1.40 (m,
2 H), 1.24 (m, 1 H), 1.17 (td, J = 13.5, 4.2 Hz, 1 H), 1.06 (s, 3 H),
1.02 (s, 3 H), 0.98 (m, 1 H), 0.86 (s, 6 H) ppm. 13C NMR
(100 MHz, CDCl3, 25 °C): δ = 157.3, 143.8, 132.5, 117.9, 113.4,
107.9, 64.2, 56.7, 54.8, 42.1, 39.7, 38.5, 37.9, 36.5, 32.9, 32.6, 28.6,
20.7, 19.9, 19.1, 18.6, 17.9, 15.7 ppm. HRESIMS [M + H]+ calcd.
for C23H35O 327.2688, found 327.2685.
Preparation of 8: Diol 7 (1.94 g, 5.39 mmol) was dissolved in THF
(20 mL). To this solution was added NaH (237 mg, 60% in oil,
5.93 mmol). The reaction was then heated to 50 °C until the solu-
tion was clear orange in color. The reaction was cooled to 0 °C,
and CS2 (1 mL, 16.6 mmol) was added. The solution was stirred
for 20 min at 0 °C, and then warmed to room temp. for an ad-
ditional 20 min, after which methyl iodide (1 mL, 16.6 mmol) was
added. The reaction was stirred at room temp. for 1 h, and then
concentrated to dryness in vacuo. The crude mixture was dissolved
in EtOAc (150 mL), and washed with 3ϫ H2O (100 mL). The or-
ganic solution was dried with MgSO4, filtered, and concentrated in
vacuo. A portion of this mixture was purified by flash chromatog-
Preparation of 3: To 10 (1.05 g, 3.20 mmol) dissolved in 15 mL of
CH2Cl2, was added a solution of BBr3 (3.2 mL, 1.0 m in CH2Cl2,
3.2 mmol). The solution was stirred at room temp. for 2 h, then
concentrated to dryness. The brown residue was dissolved in EtOAc
(200 mL), and washed with H2O (200 mL) until the pH of the
aqueous layer was neutral. The crude product was purified by flash
chromatography (hexanes/EtOAc) to yield 3 (931 mg, 2.98 mmol,
93%) as a white solid. 3: [α]2D4 = +7.22 (c = 3.35). 1H NMR
(600 MHz, CDCl3, 25 °C): δ = 6.54 (s, 1 H), 6.34 (s, 1 H), 2.58 (m,
1 H), 2.47 (dd, J = 14.4, 6.04 Hz, 1 H), 2.33 (dt, J = 11.7, 3.0 Hz,
Eur. J. Org. Chem. 0000, 0–0
© 0000 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
www.eurjoc.org
7

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/KAP1
Date: 02-08-12 17:00:27
Pages: 14
R. J. Andersen et al.
FULL PAPER
1 H), 2.25 (s, 3 H), 1.75 (m, 1 H), 1.74 (m, 1 H), 1.73 (m, 1 H),
1.70 (m, 1 H), 1.59 (m, 1 H), 1.52 (m, 1 H), 1.43 (m, 1 H), 1.41 6.3 Hz, 1 H), 1.59–1.74 (m, 3 H), 1.54 (m, 2 H), 1.40 (m, 2 H), 1.19
(m, 1 H), 1.17 (td, J = 13.7, 4.4 Hz, 1 H), 1.06 (s, 3 H), 1.02 (s, 3 (td, J = 13.5, 4.5 Hz, 1 H), 1.09 (s, 3 H), 1.04 (s, 3 H), 0.98–1.01
H), 1.00 (m, 1 H), 0.98 (m, 1 H), 0.86 (s, 6 H) ppm. 13C NMR (m, 2 H), 0.88 (s, 6 H) ppm. 13C NMR (100 MHz, CDCl3, 25 °C):
(150 MHz, CDCl3, 25 °C): δ = 153.4, 144.7, 144.3, 133.2, 115.0, δ = 159.3, 155.8, 145.2, 133.7, 101.9, 96.7, 64.7, 57.5, 55.4, 55.1,
(dd, J = 14.4, 6.3 Hz, 1 H), 2.43 (m, 1 H), 1.77 (dd, J = 12.6,
109.8, 64.5, 57.1, 47.0, 42.5, 40.1, 38.9, 36.9, 33.4, 33.1, 28.9, 21.1, 46.3, 42.6, 40.2, 38.5, 37.0, 33.4, 33.1, 29.5, 21.1, 20.4, 19.5, 18.4,
20.4, 19.6, 18.9, 18.3, 16.1 ppm. HRESIMS [M + H]+ calcd. for
C22H33O 313.2531, found 313.2526; Elemental analysis calcd.
(found) for C22H32O: Theoretical to be C, 84.56 (84.28); H, 10.32
(10.68). The structure and absolute configuration of 3 were con-
firmed by single-crystal X-ray diffraction analysis. (See Supporting
Information).
16.2 ppm. HRESIMS [M + H]+ calcd. for C23H35O2 343.2637,
found 343.2633.
Preparation of 18: Following the procedure used to prepare 3, the
following amounts were used; compound 17 (536 mg, 1.56 mmol)
in CH2Cl2 (50 mL); BBr3 (7 mL, 1.0 m in CH2Cl2, 7.0 mmol). The
crude residue was crystallized from CH2Cl2 to yield 18 (295 mg,
0.94 mmol, 60%). 18: 1H NMR (600 MHz, CD3OD, 25 °C): δ =
6.15 (s, 1 H), 6.01 (s, 1 H), 2.51 (m, 1 H), 2.44 (m, 1 H), 2.38 (dd,
J = 14.2, 6.0 Hz, 1 H), 1.72 (m, 1 H), 1.67–1.69 (m, 2 H), 1.55–
1.64 (m, 2 H), 1.51 (m, 1 H), 1.41 (m, 2 H), 1.20 (td, J = 13.4,
4.5 Hz, 1 H), 1.06 (s, 3 H), 1.03 (s, 3 H), 1.00 (m, 2 H), 0.88 (s, 3
Preparation of 14: Following a procedure similar to that used to
prepare 7, the following amounts were used; 1-bromo-3,5-di-
methoxybenzene (12) (4.84 g, 22.3 mmol) in THF (40 mL); tBuLi
(26.2 mL, 1.7 m in pentane, 44.6 mmol); aldehyde
7 (1.77 g,
7.44 mmol) in THF (20 mL). Yields 14 (1.7 g, 4.5 mmol, 61%) as
a white foam. 14: 1H NMR (400 MHz, CDCl3, 25 °C): δ = 6.57 (d, H), 0.87 (s, 3 H) ppm. 13C NMR (150 MHz, CD3OD, 25 °C): δ =
J = 2.4 Hz, 2 H), 6.32 (t, J = 2.2 Hz, 1 H), 4.75 (d, J = 8.3 Hz, 1
H), 3.76 (s, 6 H), 2.07 (d, J = 8.1 Hz, 1 H), 1.81 (dt, J = 12.2,
3.0 Hz, 1 H), 1.54–1.68 (m, 2 H), 1.51 (s, 3 H), 1.25–1.44 (m, 2 H),
1.24 (m, 1 H), 1.14 (m, 2 H), 1.00 (s, 3 H), 0.95 (m, 1 H), 0.87 (dd,
J = 12.1, 1.8 Hz, 1 H), 0.82 (s, 3 H), 0.76 (s, 3 H), 0.37 (m, 1
H) ppm. 13C NMR (100 MHz, CDCl3, 25 °C): δ = 160.7, 150.1,
105.8, 99.1, 75.8, 74.4, 62.8, 55.8, 55.3, 44.1, 41.3, 40.6, 38.6, 33.5,
33.2, 26.0, 21.6, 19.8, 18.3, 15.9 ppm. HRESIMS [M + Na]+ calcd.
for C23H36O4Na 399.2511, found 399.2510.
157.1, 154.1, 146.4, 146.4, 104.7, 101.8, 66.2, 58.9, 47.2, 43.9, 41.5,
39.9, 38.1, 34.1, 34.0, 30.2, 21.6, 21.0, 20.7, 19.5, 16.8 ppm. HRES-
IMS [M + H]+ calcd. for C21H31O2 315.2324, found 315.2323.
Preparation of 20: 3,5-dimethoxybromobenzene (12) (1.0 g,
4.60 mmol) was dissolved in THF (23 mL) and cooled to –78 °C,
to which nBuLi (1.6 m, 3.45 mL, 5.52 mmol) was added dropwise,
and allowed to stir for 15 min. To this solution was added Li2CuCl4
(0.1 m, 1.38 mL, 0.1 mmol) was allowed to stir for 10 min at –78 °C
before E,E-farnesyl bromide (19) (1.64 g, 5.75 mmol) dissolved in
THF (20 mL) was added dropwise. The reaction mixture was
warmed with stirring from –78 °C to room temp. overnight and it
was then quenched with saturated NH4Cl (50 mL). The aqueous
phase was extracted 3ϫ with CH2Cl2 (150 mL) and the organic
Preparation of 15: Following a procedure similar to that used to
prepare 8, the following amounts were used; diol 14 (1.60 g,
4.25 mmol) in THF (20 mL); NaH (187 mg, 60% in oil,
4.67 mmol); CS2 (280 mL, 4.67 mmol); methyl iodide (293 mL,
4.67 mmol); Yields 15 (1.22 g, 3.25 mmol, 76%). 15: 1H NMR extracts were dried with MgSO4, and concentrated in vacuo. The
(400 MHz, CDCl3, 25 °C): δ = 6.60 (d, J = 2.2 Hz, 2 H), 6.25 (t, J
crude mixture was purified with flash chromatography (hexanes/
= 2.2 Hz, 1 H), 5.18 (d, J = 5.0 Hz, 1 H), 3.75 (s, 6 H), 2.38 (s, 3 EtOAc, 30:1), to give 20 as a clear oil (1.02 g, 2.99 mmol, 65%).
H), 2.19 (d, J = 5.2 Hz, 1 H), 1.79 (m, 3 H), 1.66 (m, 1 H), 1.56
(dt, J = 13.7, 3.5 Hz, 1 H), 1.51 (s, 3 H), 1.46 (m, 1 H), 1.32 (m, 2
H), 1.01 (s, 3 H), 0.99 (m, 1 H), 0.87 (m, 1 H), 0.81 (s, 3 H), 0.77
(s, 3 H), 0.60 (td, J = 12.9, 3.5 Hz, 1 H) ppm. 13C NMR (100 MHz,
CDCl3, 25 °C): δ = 189.9, 160.6, 151.0, 106.2, 97.9, 74.2, 65.0, 55.9,
55.2, 46.9, 46.2, 41.4, 41.0, 40.2, 33.4, 33.3, 26.4, 21.3, 20.3, 18.4,
20: 1H NMR (400 MHz, CDCl3, 25 °C): δ = 6.36 (d, J = 2.3 Hz, 2
H), 6.30 (t, J = 2.7 Hz, 1 H), 5.34 (t, J = 7.3 Hz, 1 H), 5.15–5.08
(m, 2 H), 3.78 (s, 6 H), 3.31 (d, 2 H), 2.16–1.96 (m, 8 H), 1.71 (s,
3 H), 1.69 (s, 3 H), 1.60 (s, 6 H) ppm. 13C NMR (100 MHz, CDCl3,
25 °C): δ = 160.8, 160.8, 144.2, 136.5, 135.1, 131.2, 124.4, 124.1,
122.6, 106.4, 106.4, 97.6, 55.2, 55.2, 39.7, 39.7, 34.4, 26.7, 26.6,
25.7, 17.6, 16.2, 16.0 ppm. HRESIMS [M + Na]+ calcd. for
C23H35O2Na 343.2637, found 343.2628.
15.9, 14.1, 13.0 ppm. HRESIMS [M
C25H38O4NaS2 489.2109, found 489.2112.
+
Na]+ calcd. for
Preparation of 16: Following the procedure used to prepare 9, the
following amounts were used; xanthate 15 (1.1 g, 2.36 mmol),
Bu3SnH (1.25 mL, 4.72 mmol) in toluene (6 mL); AIBN (10 mg,
1.64 mmol) added every hour until reaction was complete. Yields
Preparation of (10S)-22: Epoxide 22 was prepared according to lit-
erature procedures using the ent-Shi catalyst 21.[11,15] Polyene 20
(1 g, 2.90 mmol) was oxidized to 22 (113.0 mg, 0.315 mmol, 11%),
which was purified by flash chromatography (hexanes/EtOAc,
16 (681 mg, 1.88 mmol, 80%): 16: 1H NMR (400 MHz, CDCl3, 12:1). Based on recovered starting material 20 (622.5 mg,
25 °C): δ = 6.46 (d, J = 2.2 Hz, 2 H), 6.25 (t, J = 2.2 Hz, 1 H), 3.77
(s, 6 H), 2.73 (dd, J = 14.6, 5.5 Hz, 1 H), 2.59 (dd, J = 14.6, 4.6 Hz,
1.82 mmol), the yield of 22 was 28 %. 22: 1H NMR (400 MHz,
CDCl3, 25 °C): δ = 6.34 (d, J = 2.2 Hz, 2 H), 6.29 (t, J = 2.2 Hz,
1 H), 1.86 (dt, J = 12.4, 3.1 Hz, 1 H), 1.61–1.72 (m, 3 H), 1.57 (dt, 1 H), 5.33 (t, J = 6.1 Hz, 1 H), 5.18 (t, J = 5.7 Hz, 1 H), 3.76 (s, 6
J = 13.5, 3.1 Hz, 1 H), 1.45 (m, 1 H), 1.40 (m, 3 H), 1.29 (m, 1 H),
1.26 (s, 3 H), 1.10 (td, J = 13.5, 4.1 Hz, 1 H), 0.95 (dd, J = 12.1,
2.0 Hz, 1 H), 0.89 (s, 3 H), 0.86 (s, 3 H), 0.80 (s, 3 H) ppm. 13C
NMR (100 MHz, CDCl3, 25 °C): δ = 160.6, 147.2, 107.1, 97.1,
74.0, 63.0, 56.1, 55.2, 55.2, 44.1, 41.7, 40.3, 39.2, 33.4, 33.2, 31.6,
24.5, 21.5, 20.3, 18.5, 15.4 ppm. HRESIMS [M + Na]+ calcd. for
C23H36O3Na 383.2562, found 383.2567.
H), 3.29 (d, J = 7.2 Hz, 2 H), 2.68 (t, J = 6.2 Hz, 1 H), 2.11–2.14
(m, 4 H), 2.04–2.08 (m, 4 H), 1.71 (s, 3 H), 1.62 (s, 3 H), 1.29 (s, 3
H), 1.25 (s, 3 H) ppm. 13C NMR (100 MHz, CDCl3, 25 °C): δ =
160.6, 143.9, 136.1, 134.0, 124.6, 122.7, 106.3, 97.4, 63.9, 58.0, 55.0,
39.5, 36.1, 34.3, 27.3, 26.4, 24.7, 18.6, 16.0, 15.9 ppm. HRESIMS
[M + Na]+ calcd. for C23H34O3Na 381.2406, found 381.2415.
Preparation of Racemic 22: To polyene 20 (9.62 g, 27.9 mmol) dis-
solved in CH2Cl2 (100 mL) was added mCPBA (5.06 g, 29.3 mmol)
dissolved in CH2Cl2 (100 mL). The reaction was allowed to stir at
Preparation of 17: Following the procedure used to prepare 10, the
following amounts were used; 16 (680 mg, 1.88 mmol) in CH2Cl2
(20 mL); SnCl4 (2 mL, 17.0 mmol). Yields 17 (540 mg, 1.56 mmol, room temp. for 3.5 h, after which it was quenched with saturated
1
83% yield). 17: H NMR (400 MHz, CDCl3, 25 °C): δ = 6.41 (s, 1 NaHCO3 (100 mL), and extracted 3ϫ with CH2Cl2 (300 mL). The
H), 6.21 (s, 1 H), 3.78 (s, 3 H), 3.76 (s, 3 H), 2.62 (m, 1 H), 2.52
organic extracts were combined, dried with MgSO4, and concen-
8
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Eur. J. Org. Chem. 0000, 0–0

Job/Unit: O20631
/KAP1
Date: 02-08-12 17:00:27
Pages: 14
SHIP1-Activating Analogs of the Sponge Meroterpenoid Pelorol
trated. The crude mixture was purified with flash chromatography
to give racemic 22 (2.24 g, 6.24 mmol, 22%). 1H, 13C, and mass
spectrometry data matched that of (10S)-22 listed above.
Preparation of 28 and 29: To a suspension of ketone 27 (250 mg,
0.761 mmol) in MeOH (50 mL) was added NaBH3CN (71.7 mg,
1.14 mmol) and NH4OAc (586.5 mg, 7.61 mmol). The reaction was
refluxed at 70 °C overnight. Upon the disappearance of staring ma-
terial, the reaction mixture was cooled, then concentrated to dry-
ness. The crude material was partitioned between H2O (150 mL)
and CH2Cl2 (150 mL) and acidified to pH 5 with 6 m HCl. The
H2O phase was then extracted 5ϫ with CH2Cl2 (200 mL). The re-
sultant H2O phase was frozen and lyophilized overnight, which
gave a white amorphous solid. To this solid was added H2O
(10 mL) and the suspension was sonicated to give a heterogeneous
mixture which was loaded on to a 10 g reversed phase Sep-pak.
[which had been pre-washed with MeOH (100 mL) followed by
H2O (100 mL)]. Once loaded, the column was flushed with water
(100 mL), 60:40 H2O:MeOH (100 mL, 3ϫ ), and MeOH (100 mL).
The fractions of interest were the first 60:40 H2O:MeOH fraction
containing 78.2 mg of 28 pure, and the second and third fraction
contained 50.7 mg of a 2:1 mixture of 28 and 29 which was sub-
sequently repurified using the same method. When fully purified
the result was 28 (112 mg, 0.306 mmol, 40%), and 29 (16.9 mg,
0.0461 mmol, 6%), with a diastereomeric ratio between the two
epimers of 20:3.
Preparation of 23: To epoxide 22 (3.53 g, 9.86 mmol) dissolved in
CH2Cl2 (105 mL) was added InBr3 (6.99 g, 19.7 mmol), and the
reaction mixture was allowed to stir at room temp. for 1 h, before
being quenched with saturated NaHCO3 (150 mL). The aqueous
layer was extracted 3ϫ with CH2Cl2 (300 mL) and the organic ex-
tracts were combined and dried with MgSO4, then concentrated.
The crude reaction mixture was purified with flash chromatography
(hexanes/EtOAc, 3:1), to give a mixture of 23 and various uncy-
clized products. The product mixture was crystallized using boiling
solvent (hexanes/EtOAc, 15:1), to give 23 (860 mg, 2.39 mmol,
24%). The structure and absolute configuration of 23 were con-
firmed by single-crystal X-ray diffraction anlysis. (See Supporting
Information). Subsequent reaction with (R)-MTPA-Cl gave the
Mosher derivatives 24. 23: [α]2D4 = +19 (c = 0.16). 1H NMR
(400 MHz, CDCl3, 25 °C): δ = 6.40 (d, J = 1.8 Hz, 1 H), 6.26 (d,
J = 1.9 Hz, 1 H), 3.77 (s, 3 H), 3.75 (s, 3 H), 3.22 (m, 1 H), 2.62
(m, 1 H), 2.50 (dd, J = 14.4, 6.2 Hz, 1 H), 2.45 (dd, J = 9.5, 3.2 Hz,
1 H), 1.74–1.55 (m, 7 H), 1.18–1.11 (m, 1 H), 1.08 (s, 3 H), 1.03 (s,
3 H), 0.99 (s, 3 H), 0.91 (m, 1 H), 0.84 (s, 3 H) ppm. 13C NMR
(100 MHz, CDCl3, 25 °C): δ = 159.3, 155.8, 144.8, 133.4, 101.9,
96.8, 79.1, 64.4, 56.1, 55.4, 55.0, 46.0, 38.8, 38.5, 38.2, 36.6, 29.5,
27.9, 27.1, 20.3, 19.2, 16.2, 15.1 ppm. HRESIMS [M + Na]+ calcd.
for C23H34O3Na 381.2406, found 381.2415.
Compound 28: [α]2D4 = –8.27 (c = 3.68). 1H NMR (600 MHz,
CD3OD, 25 °C): δ = 6.16 (s, 1 H, 17-H), 6.02, (d, J = 1.5 Hz, 1 H,
19-H), 2.93 (dd, J = 12.5, 4.3 Hz, 1 H, 3-H), 2.57 (t, J = 13.6 Hz,
1 H, 15-H), 2.51 (dt, J = 12.5, 2.9 Hz, 1 H, 7-H), 2.42 (dd, J =
14.3, 6.0 Hz, 1 H, 15-H), 1.85 (qd, J = 13.1, 3.4 Hz, 1 H, 2-H),
1.79–1.73 (m, 2 H, 1-H/2-H), 1.71–1.67 (m, 3 H, 6-H/7-H), 1.63
(td, J = 12.3, 3.5 Hz, 1 H, 9-H), 1.27 (td, J = 13.3, 3.4 Hz, 1 H, 1-
H), 1.11 (dd, J = 11.3, 2.3 Hz, 1 H, 5-H), 1.085 (s, 3 H, 13-H),
1.081 (s, 3 H, 14-H), 1.076 (s, 3 H, 11-H), 0.94 (s, 3 H, 12-H) ppm.
13C NMR (150 MHz, CD3OD, 25 °C): δ = 157.5 (C-18), 154.2 (C-
20), 145.9 (C-16), 131.7 (C-21), 104.7 (C-17), 101.9 (C-19), 65.6 (C-
9), 61.7 (C-3), 57.6 (C-5), 46.8 (C-8), 39.6 (C-7), 39.2 (C-6), 37.8
(C-1), 37.7 (C-4), 30.1 (C-15), 28.2 (C-10), 24.3 (C-2), 20.8 (C-13),
20.2 (C-11), 16.4 (C-14), 15.9 (C-12) ppm. HRESIMS [M + H]+
calcd. for C21H32NO2 330.2433, found 330.2441.
Preparation of 26: To alcohol 23 (600 mg, 1.67 mmol) dissolved in
CH2Cl2 (85 mL) was added Dess–Martin periodinane (1.41 g,
3.34 mmol) and the mixture was allowed to stir at room temp. for
1.5 h. The reaction was quenched by addition of saturated
NaHCO3 (75 mL), and the aqueous phase was extracted 3ϫ with
CH2Cl2 (200 mL). The organic extracts were combined, dried with
MgSO4, and concentrated. The crude product was purified using
flash chromatography (hexanes/EtOAc, 7:1), to give 26 (476 mg,
1.34 mmol, 80%) as a white crystalline solid. 26: [α]2D4 = +26.78 (c
= 0.083). 1H NMR (400 MHz, CDCl3, 25 °C): δ = 6.41 (s, 1 H),
6.27 (s, 1 H), 3.77 (s, 3 H), 3.75 (s, 3 H), 2.71–2.65 (m, 1 H), 2.64–
2.56 (m, 2 H), 2.54–2.41 (m, 2 H), 1.87–1.81 (m, 1 H), 1.78–1.73
(m, 2 H), 1.71–1.48 (m, 4 H), 1.13 (s, 3 H), 1.11 (s, 6 H), 1.09 (s, 3
H) ppm. 13C NMR (100 MHz, CDCl3, 25 °C): δ = 217.2, 159.5,
155.8, 144.4, 132.9, 101.9, 96.8, 63.4, 55.4, 55.3, 54.9, 47.5, 45.8,
38.8, 37.4, 36.2, 33.9, 29.5, 26.5, 20.7, 20.5, 19.8, 15.5 ppm. HRES-
IMS [M + Na]+ calcd. for C23H32O3Na 379.2249, found 379.2243.
Compound 29: [α]2D4 = +6.98 (c = 1.80). 1H NMR (600 MHz,
CD3OD, 25 °C): δ = 6.16 (s, 1 H), 6.02 (d, J = 1.2 Hz, 1 H), 3.09
(m, 1 H), 2.58 (t, J = 13.7 Hz, 1 H), 2.51 (m, 1 H), 2.44 (dd, J =
14.2, 6.0 Hz, 1 H), 2.29 (tt, J = 14.9, 3.3 Hz, 1 H), 1.83 (dd, J =
12.9, 6.1 Hz, 1 H), 1.71–1.69 (m, 1 H), 1.68–1.66 (m, 1 H), 1.64–
1.59 (m, 1 H), 1.49 (dt, J = 11.4, 2.1 Hz, 1 H) 1.39 (d, J = 8.5 Hz,
1 H), 1.34–1.27 (m, 2 H), 1.11 (s, 3 H), 1.09 (s, 3 H), 1.07 (s, 3 H),
1.01 (s, 3 H) ppm. 13C NMR (150 MHz, CD3OD, 25 °C): δ = 157.5,
154.2, 146.0, 131.8, 104.7, 101.9, 65.1, 59.5, 51.4, 47.1, 39.6, 37.9,
36.6, 34.1, 30.1, 28.4, 22.9, 22.7, 20.9, 20.2, 16.5 ppm. HRESIMS
[M + H]+ calcd. for C21H32NO2 330.2433, found 330.2440.
Preparation of 27: To ketone 26 (240 mg, 0.67 mmol), dissolved in
CH2Cl2 (20 mL) stirring at 0 °C was added BBr3 (1.0 m, 2.7 mL,
2.69 mmol). After stirring for 1 h at 0 °C, 26 was still present, so
the reaction was allowed to reach room temp. over the next 2 h.
The reaction was quenched with MeOH (1 mL), and H2O (50 mL)
was added to the mixture. The aqueous phase was extracted 3ϫ
with CH2Cl2 (150 mL). The combined organic extracts were dried
with MgSO4 and concentrated. The crude mixture was purified
with flash chromatography (hexanes/EtOAc, 3:2) to give 27
Preparation of 31: To dimethoxybromobenzene 12 (21.7 g, 0.1 mol)
dissolved in THF (200 mL) and cooled to –78 °C, nBuLi (69 mL,
1.6 m in hexanes, 0.11 mol) was added dropwise by syringe over a
period of 30 min, and the solution was stirred for 20 min. Bromide
30 (17.1 g, 0.11 mol) in THF (50 mL) was added dropwise over a
period of 30 min, and the reaction mixture was stirred at –78 °C
for 45 min. The reaction was then quenched with H2O (25 mL),
and the reaction mixture was extracted into EtOAc (200 mL) and
washed with 2ϫ H2O (150 mL). The organic phase was dried with
Na2SO4, filtered, and concentrated to dryness. The crude product
was purified by column chromatography to yield 31 (16.5 g,
(190 mg, 0.578 mmol, 86%) as a white crystalline solid. 27: [α]2D4
=
+24.07 (c = 0.81). 1H NMR [400 MHz, (CD3)2CO, 25 °C]: δ = 7.76
(s, 1 H), 7.73 (s, 1 H), 6.24 (t, J = 1.0 Hz, 1 H), 6.13 (d, J = 1.6 Hz),
2.66–2.61 (m, 1 H), 2.59–2.52 (m, 2 H), 2.49–2.46 (m, 1 H), 2.44–
2.37 (m, 1 H), 1.86–1.82 (m, 1 H), 1.81–1.77 (m, 1 H), 1.76–1.71
(m, 1 H), 1.67–1.55 (m, 4 H), 1.15 (s, 3 H), 1.13 (s, 3 H), 1.07 (s, 3
H), 1.09 (s, 3 H) ppm. 13C NMR [100 MHz, (CD3)2CO, 25 °C]: δ
= 216.9, 158.5, 154.8, 146.7, 131.9, 105.8, 102.8, 65.4, 57.2, 48.9,
47.3, 40.5, 39.6, 38.0, 35.4, 30.9, 27.9, 22.2, 22.1, 21.3, 16.9 ppm.
HRESIMS [M + Na]+ calcd. for C21H28O3Na 351.1936, found
351.1929.
1
0.08 mol, 80% yield) as a pale yellow oil. 31: H NMR (400 MHz,
CD2Cl2, 25 °C): δ = 6.40 (s, 2 H), 6.34 (s, 1 H), 5.38 (t, J = 7.2 Hz,
1 H), 3.81 (s, 6 H), 3.34 (d, J = 7.2 Hz, 2 H), 1.81 (s, 3 H), 1.78 (s,
Eur. J. Org. Chem. 0000, 0–0
© 0000 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
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9

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/KAP1
Date: 02-08-12 17:00:27
Pages: 14
R. J. Andersen et al.
warmed to room temp. and concentrated to half its original volume
FULL PAPER
3 H) ppm. 13C NMR (100 MHz, CD2Cl2, 25 °C): δ = 161.3, 144.7,
133.0, 123.3, 106.7, 97.9, 55.5, 34.9, 25.9, 17.9 ppm. HRESIMS [M under vacuum. H2O (250 mL) and EtOAc (400 mL) were added
+ H]+ calcd. for C13H19O2 207.1385, found 207.1380.
and the organic phase was washed with 2ϫ H2O (200 mL). The
organic phase was dried with Na2SO4, and concentrated to dryness.
The crude product was purified by column chromatography to
yield 36 (2.5 g, 8.11 mmol, 80%) as a colorless semisolid. 36: 1H
NMR (400 MHz, CD2Cl2, 25 °C): δ = 7.69 (d, J = 8.2 Hz, 2 H),
7.32 (d, J = 7.9 Hz, 2 H), 5.19 (t, J = 6.8 Hz, 1 H), 3.77 (d, J =
7.9 Hz, 2 H), 2.61 (t, J = 6.2 Hz, 1 H), 2.42 (s, 3 H), 2.11 (m, 2 H),
1.53 (m, 2 H), 1.34 (s, 3 H), 1.25 (s, 3 H), 1.21 (s, 3 H) ppm. 13C
NMR (100 MHz, CD2Cl2, 25 °C): δ = 145.7, 145.0, 136.2, 129.9,
128.7, 111.4, 63.7, 58.3, 56.3, 36.7, 27.5, 24.9, 21.7, 18.8, 16.3 ppm.
HRESIMS [M + Na]+ calcd. for C17H24O3NaS 331.1344, found
331.1338.
Preparation of 32: SeO2 (1.34 g, 12.1 mmol) was slurried in CH2Cl2
(100 mL). tBuOOH solution (6.95 mL, 70% in H2O, 48.6 mmol)
was then added and the resulting mixture was stirred until all solids
had dissolved. A solution of 31 (5 g, 24.3 mmol) in CH2Cl2 (25 mL)
was added and the reaction mixture was stirred rapidly at room
temp. for 20 h. The CH2Cl2 was removed under reduced pressure,
and the resulting residue was dissolved in Et2O (100 mL). The or-
ganic phase was washed with 3ϫ 10% KOH (200 mL), dried with
Na2SO4, filtered and concentrated to yield a pale yellow oil. This
residue was dissolved in 40 mL of MeOH, cooled to 0 °C and
NaBH4 (920 mg, 24.3 mmol) was added in portions. Once added,
the reaction mixture was stirred for 1 h. The reaction was quenched
by the addition of 1 m HCl, and the crude product was extracted
into EtOAc. The organic phase was washed with saturated
NaHCO3 (100 mL), dried with Na2SO4, and concentrated in vacuo.
The crude product was purified by column chromatography (hex-
anes/EtOAc, 2:1) to yield 32 (2.59 g, 11.7 mmol, 48%) as a pale
Preparation of 37: Sulfone 36 (355 mg, 1.15 mmol) and bromide 35
(393 mg, 1.38 mmol) were dissolved in THF (12 mL) and cooled to
–78 °C. KOtBu (143 mg, 1.27 mmol) was then added and the reac-
tion mixture was stirred at –78 °C for 2 h. The reaction was
quenched with H2O (100 mL) and extracted into EtOAc (150 mL).
The organic phase was dried with Na2SO4, filtered and concen-
trated. The crude reaction mixture was purified by column
chromatography to yield 37 (574 mg, 1.12 mmol, 97%) as a color-
1
yellow oil. 32: H NMR (400 MHz, CD2Cl2, 25 °C): δ = 6.34 (s, 2
H), 6.29 (s, 1 H), 5.57 (t, J = 7.1 Hz, 1 H), 3.99 (s, 2 H), 3.75 (s, 6
H), 3.32 (d, J = 7.1 Hz, 2 H), 1.88 (s, 1 H), 1.74 (s, 3 H) ppm. 13C
NMR (100 MHz, CD2Cl2, 25 °C): δ = 161.2, 143.9, 136.4, 124.1,
106.7, 97.9, 68.6, 55.5, 34.4, 13.8 ppm. HRESIMS [M + Na]+
calcd. for C13H18O3Na 245.1154, found 245.1147.
1
less oil. 37: H NMR (400 MHz, CD2Cl2, 25 °C): δ = 7.68 (d, J =
7.9 Hz, 2 H), 7.68 (d, J = 7.9 Hz, 2 H), 7.31 (d, J = 7.8 Hz, 2 H),
6.25 (s, 3 H), 4.91 (m, 1 H), 3.92 (m, 1 H), 3.72 (s, 6 H), 3.22 (d, J
= 7.2 Hz, 2 H), 2.86 (d, J = 13.1 Hz, 1 H), 2.58 (m, 1 H), 2.42 (s,
3 H), 2.30 (m, 1 H), 2.03 (m, 1 H), 1.64 (s, 3 H), 1.43 (m, 2 H),
1.26 (s, 3 H), 1.25 (s, 3 H), 1.22 (s, 3 H) ppm. 13C NMR (100 MHz,
CD2Cl2, 25 °C): δ = 161.2, 144.9, 144.8, 144.7, 143.8, 135.5, 135.4,
131.7, 129.7, 129.5, 126.9, 117.9, 106.7, 97.7, 63.6, 63.6, 58.2, 55.5,
38.1, 37.9, 36.6, 36.5, 34.7, 27.5, 24.9, 21.7, 18.8, 16.6, 16.3,
Preparation of 33: Alcohol 32 (2.59 g, 11.7 mmol) and PPh3 (3.65 g,
13.9 mmol) were dissolved in CH2Cl2 (20 mL) and cooled to 0 °C.
CBr4 (4.25 g, 12.8 mmol) was added and the reaction mixture was
stirred for 1 h at 0 °C. The solution was concentrated to dryness
and the crude product was purified by flash chromatography (hex-
anes/EtOAc, 2:1) to yield bromide 33 (2.53 g, 8.87 mmol, 76%) as
16.2 ppm. HRESIMS [M
535.2494, found 535.2507.
+
Na]+ calcd. for C30H40O5NaS
1
a colorless oil. 33: H NMR (400 MHz, CD2Cl2, 25 °C): δ = 6.33
(s, 2 H), 6.31 (s, 1 H), 5.79 (t, J = 7.3 Hz, 1 H), 4.04 (s, 2 H), 3.76
(s, 6 H), 3.33 (d, J = 7.3 Hz, 2 H), 1.87 (s, 3 H) ppm. 13C NMR
(100 MHz, CD2Cl2, 25 °C): δ = 161.3, 142.9, 133.6, 129.7, 106.6,
98.2, 55.5, 41.8, 34.9, 14.9 ppm. HREIMS [M]+ calcd. for
C13H17O279Br 284.04119, found 284.04102.
Preparation of 22: Sulfone 37 (400 mg, 0.78 mmol) and
PdCl2(dppp) (92 mg, 0.156 mmol) were slurried in THF (16 mL)
and cooled to 0 °C. LiBEt3H (1.0, 1.56 mL, 1.56 mmol) was then
added dropwise over a period of 10 min. The reaction mixture was
stirred at 0 °C for 1 h, then H2O was added (100 mL). The reaction
mixture was extracted into EtOAc (200 mL) and washed with H2O
(150 mL). The organic phase was dried with Na2SO4, filtered, and
concentrated. The crude product was purified by column
chromatography to yield 22 (212 mg, 0.59 mmol, 76%) as a color-
Preparation of 35: Geranyl bromide (34) (10 g, 46 mmol), Bu4NI
(1.7 g, 4.6 mmol) and sodium p-toluenesulfonate (12.3 g, 69 mmol)
were combined in THF (500 mL) and stirred at room temp. for
24 h. The reaction was quenched by the addition of saturated
Na2S2O5 (100 mL) and the crude product was extracted into
EtOAc (400 mL). The organic phase was washed with 2ϫ H2O
(200 mL) and 1ϫ saturated NaHCO3 (100 mL), dried with Na2SO4
and concentrated to yield 35 (13.4 g, 46 mmol, quantitative yield)
as a yellow oil that crystallized upon standing. 35: 1H NMR
(400 MHz, CD2Cl2, 25 °C): δ = 7.71 (d, J = 8.1 Hz, 2 H), 7.35 (d,
J = 7.9 Hz, 2 H), 5.15 (t, J = 7.3 Hz, 1 H), 5.05 (m, 1 H), 3.77 (d,
J = 7.9 Hz, 2 H), 2.44 (s, 3 H), 2.01 (s, 4 H), 1.68 (s, 3 H), 1.59 (s,
3 H), 1.32 (s, 3 H) ppm. 13C NMR (100 MHz, CD2Cl2, 25 °C): δ
= 146.4, 144.9, 136.4, 132.2, 129.9, 128.8, 123.9, 110.9, 56.5, 40.1,
26.6, 25.7, 21.7, 17.7, 16.3 ppm. HRESIMS [M + Na]+ calcd. for
C17H24O2NaS 315.1395, found 315.1388.
1
less oil. 22: H NMR (400 MHz, CDCl3, 25 °C): δ = 6.34 (d, J =
2.2 Hz, 2 H), 6.29 (t, J = 2.2 Hz, 1 H), 5.33 (t, J = 6.1 Hz, 1 H),
5.18 (t, J = 5.7 Hz, 1 H), 3.76 (s, 6 H), 3.29 (d, J = 7.2 Hz, 2 H),
2.68 (t, J = 6.2 Hz, 1 H), 2.11–2.14 (m, 4 H), 2.04–2.08 (m, 4 H),
1.71 (s, 3 H), 1.62 (s, 3 H), 1.29 (s, 3 H), 1.25 (s, 3 H) ppm. 13C
NMR (100 MHz, CDCl3, 25 °C): δ = 160.6, 143.9, 136.1, 134.0,
124.6, 122.7, 106.3, 97.4, 63.9, 58.0, 55.0, 39.5, 36.1, 34.3, 27.3,
26.4, 24.7, 18.6, 16.0, 15.9 ppm. HRESIMS [M + Na]+ calcd. for
C23H34O3Na 381.2406, found 381.2415.
Preparation of 24 and 25: Alcohol 23 (219.4 mg, 0.610 mmol) ob-
tained by flash chromatography purification (hexanes/EtOAc, 3:1)
of the reaction mixture produced by cyclization of epoxide 22
(Scheme 3) was dissolved in CH2Cl2 (4 mL) and to this mixture
was added pyridine (0.074 mL, 0.92 mmol) and DMAP (7.4 mg,
0.061 mmol) and the solution was cooled to 0 °C. (R)-(–)-MTPA-
Cl (169.5 mg, 0.671 mmol) was added and the mixture was warmed
to room temp. overnight. The reaction was quenched with satu-
rated NH4Cl (50 mL) and the H2O layer was extracted 3ϫ with
CH2Cl2 (200 mL). The organic extracts were combined, dried with
MgSO4, and concentrated. The product mixture was the purified
Preparation of 36: Sulfone 35 (3 g, 10.3 mmol) was dissolved in a
mixture of CH3CN:dimethoxymethane (51 mL:103 mL). Na2B7O7
(0.5 m, 103 mL) in 4ϫ10–4 m Na2(EDTA) was added, followed by
the ent-Shi catalyst 21 (810 mg, 3.1 mmol) and NH4HSO4
(153.9 mg, 0.45 mmol). The mixture was cooled to –10 °C, and
solutions of oxone (8.73 g, 14.2 mmol) in Na2(EDTA) (4ϫ10–4 m,
67 mL) and K2CO3 (8.22 g, 59.5 mmol) in H2O (67 mL) were
added using a syringe pump over 2 h. The reaction mixture was
10
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© 0000 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
Eur. J. Org. Chem. 0000, 0–0

Job/Unit: O20631
/KAP1
Date: 02-08-12 17:00:27
Pages: 14
SHIP1-Activating Analogs of the Sponge Meroterpenoid Pelorol
using flash chromatography (hexanes/EtOAc, 12:1), to give a mix-
ture of 24 and 25. The structure and absolute configuration of 25
were confirmed by single-crystal X-ray diffraction analysis. (See
Supporting Information). Integration of signals for diastereomers
in the 1H NMR spectrum of the crude mixture gave a dia-
stereomeric ratio of 97:3 (24:25) meaning that the epoxidation pro-
ceeded in ca. 95% ee. 24: [α]2D4 = –32 (c = 0.65). 1H NMR
(400 MHz, CDCl3, 25 °C): δ = 7.54 (m, 2 H), 7.41 (m, 3 H), 6.40
(d, J = 1.7 Hz, 1 H), 6.26 (d, J = 1.8 Hz, 1 H), 4.72 (dd, J = 11.5,
4.9 Hz, 1 H), 3.77 (s, 3 H), 3.75 (s, 3 H), 3.54 (s, 3 H), 2.62 (m, 1
H), 2.51 (dd, J = 14.4, 6.1 Hz, 1 H), 2.46 (dd, J = 8.4, 2.9 Hz, 1
H), 1.85–1.76 (m, 1 H), 1.74–1.67 (m, 3 H), 1.65–1.57 (m, 3 H),
1.23 (td, J = 13.4, 4.1 Hz, 1 H), 1.07 (s, 3 H), 1.04 (s, 3 H), 1.04
(m, 1 H), 0.92 (s, 3 H), 0.87 (s, 3 H) ppm. 13C NMR (100 MHz,
CDCl3, 25 °C): δ = 166.3, 159.5, 155.8, 144.7, 133.2, 132.3, 129.5,
128.3, 128.3, 127.6, 127.6, 124.9, 122.0 101.9, 96.9, 84.5, 64.2, 56.2,
55.4, 55.3, 55.1, 46.1, 38.1, 38.0, 37.9, 36.5, 29.5, 28.1, 23.0, 20.3,
Preparation of ent-18: To 39 (20 mg, 0.058 mmol) dissolved in
CH2Cl2 (20 mL) and was added boron tribromide (0.17 mL,
0.175 mmol, 1.0 m solution in CH2Cl2). After stirring for 90 min
the reaction was quenched with the addition of MeOH (0.1 mL),
and concentrated under a stream of nitrogen. The crude mixture
was the purified with flash chromatography to give ent-18 (12.1 mg,
0.038 mmol, 66%). The 1H and 13C NMR spectra were identical
to 18. [α]2D4 = –18.1 (c = 0.05). HRESIMS [M + H]+ calcd. for
C21H29O2 313.2176, found 313.2168.
Preparation of 40: To 27 (20 mg, 0.060 mmol) dissolved in pyridine
(1 mL) was added hydroxylamine hydrochloride (33.8 mg,
0.49 mmol), and heated at 50 °C. After 3.5 h the reaction mixture
was cooled to room temp., saturated NH4Cl (10 mL) solution was
added, and the aqueous phase was extracted three times with
CH2Cl2 (75 mL). The organic extracts were combined and dried
with MgSO4, and concentrated. The crude was purified with flash
chromatography (hexanes/EtOAc, 1:1) to give 40 as a white solid
(15.5 mg, 0.045 mmol, 75%). [α]2D4 = –14.94 (c = 0.02). 1H NMR
[400 MHz, (CD3)2CO, 25 °C]: δ = 6.22 (s, 1 H), 6.12 (s, 1 H), 3.06
(ddd, J = 15.9, 3.2, 2.7 Hz, 1 H), 2.59 (t, J = 14.1 Hz, 1 H), 2.53
(dt, J = 12.1, 3.1 Hz, 1 H), 2.44 (dd, J = 14.4, 6.1 Hz, 1 H), 2.29
(ddd, J = 18.5, 6.4, 5.8 Hz, 1 H), 1.75–1.72 (m, 1 H), 1.71–1.69 (m,
2 H), 1.68–1.66 (m, 1 H), 1.65–1.61 (m, 1 H), 1.29–1.23 (m,2 H),
1.15 (s, 3 H), 1.14 (s, 3 H), 1.11 (s, 3 H), 1.08 (s, 3 H) ppm. 13C
NMR [100 MHz, (CD3)2CO, 25 °C]: δ = 171.9, 165.8, 158.5, 154.8,
146.8, 132.1, 105.8, 102.8, 65.9, 61.5, 58.3, 47.4, 41.7, 40.0, 38.4,
29.2, 24.3, 21.7, 18.1, 16.8, 15.5 ppm. HRESIMS [M + H]+ calcd.
for C21H30O3N 344.2226, found 344.2230.
19.0, 16.2, 16.1 ppm. HRESIMS [M
C33H41O5F3Na 597.2804, found 597.2814.
+
Na]+ calcd. for
25: [α]2D4 = –23 (c = 1.20). H NMR (400 MHz, CDCl3, 25 °C): δ
= 7.57 (m, 2 H), 7.41 (t, 3 H), 6.41 (s, 1 H), 6.26 (d, J = 1.5 Hz, 1
H), 4.75 (dd, J = 10.4, 5.9 Hz, 1 H), 3.77 (s. 3 H), 3.75 (s, 3 H),
3.58 (s, 3 H), 2.64 (t, J = 13.8 Hz, 1 H), 2.52 (dd, J = 14.3, 6.1 Hz,
1 H), 2.46 (m, 1 H), 1.91–1.79 (m, 2 H), 1.75–1.70 (m, 2 H), 1.66–
1.62 (m, 4 H), 1.25 (td, J = 12.5, 4.9 Hz, 1 H), 1.08 (s, 3 H), 1.07
(s, 3 H), 0.86 (s, 3 H), 0.83 (s, 3 H) ppm. 13C NMR (100 MHz,
CDCl3, 25 °C): δ = 166.1, 159.5, 155.8, 144.7, 133.2, 132.7, 129.5,
128.3, 127.3, 124.9, 122.1, 101.9, 96.9, 84.3, 64.2, 56.2, 55.42, 55.39,
55.1, 46.1, 38.1, 38.0, 37.9, 36.5, 29.5, 27.7, 23.4, 20.3, 19.0, 16.2,
1
Preparation of 41: To 40 (10.3 mg, 0.029 mmol) dissolved in
CH2Cl2 (1 mL) at 0 °C was added trfifluoroacetic anhydride
(0.11 mL, 0.79 mmol) and allowed to stir for 1 h. The reaction was
quenched with H2O (0.1 mL) and the reaction mixture was concen-
trated under a stream of nitrogen. The crude was purified with
flash chromatography (CH2Cl2:MeOH 12:1) to give 41 (10.0 mg,
15.9 ppm. HRESIMS [M
597.2804, found 597.2814.
+
Na]+ calcd. for C33H41O5F3Na
Preparation of ent-28 and ent-29: Preparation was identical to 28
and 29, with the exception that the original Shi catalyst[11] was used
1
in the epoxidation step in place of the ent-Shi catalyst 21. H, and
1
0.029 mmol, 100%) as a white solid. [α]2D4 = +122.1 (c = 0.07). H
13C NMR spectroscopic data for ent-28 and ent-29 matched that
of 28 and 29, respectively. The structure and absolute configuration
of ent-28 were confirmed by single-crystal X-ray diffraction anlysis.
(See Supporting Information). ent-28: [α]2D4 = +8.3 (c = 3.21). ES-
IMS [M + H]+ calcd. for C21H32NO2 330.2433, found 330.2440.
ent-29: [α]2D4 = –5.7 (c = 1.47). HRESIMS [M + H]+ calcd. for
C21H32NO2 330.2433, found 330.2433.
NMR (400 MHz, CD3OD, 25 °C): δ = 6.17 (d, J = 1.7 Hz, 1 H),
6.02 (d, J = 1.9 Hz, 1 H), 3.45 (s, 1 H), 2.65–2.56 (m, 2 H), 2.51–
2.43 (m, 3 H), 1.83–1.70 (m, 4 H), 1.69–1.61 (m, 2 H), 1.59–1.52
(m, 1 H), 1.33 (s, 3 H), 1.32 (s, 3 H), 1.22 (s, 3 H), 1.11 (s, 3 H) ppm.
13C NMR (100 MHz, CD3OD, 25 °C): δ = 179.3, 157.5, 154.3,
145.8, 131.6, 104.6, 101.9, 65.5, 57.8, 56.9, 46.6, 41.2, 39.3, 39.0,
33.7, 32.6, 30.6, 26.4, 24.3, 20.3, 17.5 ppm. HRESIMS [M + Na]+
calcd. for C21H29NO3Na 366.2045, found 366.2035.
Preparation of 39: To sodium hydride (8.0 mg, 60% in mineral oil,
0.20 mmol) washed two times with hexanes (1 mL) was added THF
(0.5 mL). To this heterogeneous mixture was added 38 (24.3 mg,
067 mmol) dissolved in THF (2 mL) and allowed to stir for 10 min.
To this mixture was added CS2 (0.024 mL, 0.402 mmol), and al-
lowed to stir for thirty minutes, after which methyl iodide
(0.037 mL, 0.60 mmol) was added neat and the mixture allowed to
stir overnight at room temp. The mixture was quenched with
MeOH (0.1 mL), concentrated under a stream of nitrogen and fil-
tered through a plug of Si gel with hexanes/EtOAc (20 mL, 3:1),
and concentrated. The crude mixture was used in the following step
without further purification. The mixture was dissolved in toluene
(3 mL) to which was added tributyltin hydride (87.5 mg,
Preparation of 42: To 41 (8.0 mg, 0.023 mmol) dissolved in THF
(4 mL) was added LiAlH4 (0.072 mL. 2.0 m in THF, 0.14 mmol)
and allowed to reflux overnight. Upon completion, the reaction
was quenched with MeOH (0.1 mL), and HCl (6 m, 0.1 mL) was
added. The mixture was concentrated and lyophilized, and purified
using a 2 g reversed phase Sep-Pak (which was washed with 10 mL
of MeOH followed by 10 mL of H2O). Once loaded, the column
was flushed with H2O (20 mL), 60:40 H2O:MeOH (50 mL), and
MeOH (50 mL). The H2O:MeOH fraction after concentration and
lyophilization contained 42 (4 mg, 0.011 mmol, 47%) as a white
solid. [α]2D4 = +20.50 (c = 0.02). 1H NMR (600 MHz, CD3OD,
25 °C): δ = 6.16 (s, 1 H), 6.03 (d, J = 1.5 Hz, 1 H), 3.23–3.15 (m,
0.30 mmol) and AIBN (0.06 mL, 0.012 mmol), and the reaction 2 H), 2.62 (t, J = 13.9 Hz, 1 H), 2.57 (dd, J = 8.2 Hz, 1 H), 2.52
mixture heated to 120 °C for thirty min. The reaction was then
allowed to cool down to room temp., and concentrated under a
stream of nitrogen. The crude mixture was purified with flash
chromatography (hexanes/EtOAc, 15:1), to give 39 (18.8 mg,
(dt, J = 12.9, 2.9 Hz, 1 H), 2.00–1.96 (m, 1 H), 1.94–1.87 (m, 3 H),
1.75–1.72 (m, 2 H), 1.70–1.66 (m, 1 H), 1.64–1.58 (m, 1 H), 1.48
(s, 3 H), 1.42 (s, 3 H), 1.39 (m, 1 H), 1.22 (s, 3 H), 1.13 (s, 3 H) ppm.
13C NMR (150 MHz, CD3OD, 25 °C): δ = 157.7, 154.3, 145.2,
131.2, 104.4, 101.9, 64.6, 63.6, 54.7, 46.2, 43.9, 42.6, 42.2, 38.3,
31.2, 27.9, 24.9, 24.3, 24.0, 19.5, 14.9 ppm. HREIMS [M]+ calcd.
for C21H31NO2 329.23548, found 329.23569.
1
0.054 mmol, 82% over two steps). The H and 13C NMR spectra
were identical to compound 17. [α]2D4 = –4.25 (c = 0.07). HRESIMS
[M + H]+ calcd. for C23H35O2 343.2637, found 343.2640.
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R. J. Andersen et al.
FULL PAPER
His-hSHIP1 Enzyme Assay: His-hSHIP1 enzyme assay was per-
formed in 96-well microtiter plates with 2.5 to 10 ng enzyme/well
and 50 ng/well, respectively, in a total volume of 25 μL of SHIP1
passive cutaneous anaphylaxis. Sixty minutes after dosing, each an-
imal was given a tail vein injection of 2% Evans’ blue (0.22 μm
filtered, in 200 μL saline) followed by a second tail intravenous in-
assay buffer [20 mm Tris HCl (pH 7.5), 10 mm MgCl2 and 0.02% jection of 100 μg DNP-HSA (in 200 μL PBS) (Sigma). Sixty min-
Tween-20]. Recombinant His-hSHIP1 enzyme was incubated with
test articles or vehicle (2% ethanol) and 50 μm inositol-1,3,4,5-tet-
rakisphosphate (IP4) for 15 min at 37 °C in a shaking incubator.
After 15 min at 37 °C, the amount of inorganic phosphate released
was assessed by the addition of BIOMOL GREEN™ reagent and
incubation for 20 min at room temp. before measuring the ab-
sorbance at 650 nm.
utes following the DNP-HSA injection, mice were euthanized using
CO2 inhalation. Ear biopsies were performed with four millimeter
punches from both ears placed into 100 μL formamide in 96 well
PCR plates to elute the Evans’ Blue dye. To minimize evaporation,
plates were then sealed during incubation in a 70 °C water bath
overnight. Eighty μL of eluents were transferred to flat-bottom 96-
well plates and read using a SpectraMax M5 spectrophotometer
(Molecular Devices, Sunnyvale, CA, USA) at 620 nm. Background
readings from all samples were taken at 740 nm and subtracted
from the 620 nm readings. A blank reading was made on a sample
of formamide and subtracted from all readings. Data are reported
as optical density.
Akt Activation Assay.
Cell Culture: MOLT-4 and Jurkat T-ALL cells were cultured in
RPMI 1640 containing 10% FBS and 1% penicillin/streptomycin
at 37 °C in a water jacketed CO2 (5%) incubator. Cells were seeded
at 0.2–0.3ϫ106 cells/mL and grown for 2 to 3 d before passaging.
Cells that exceeded 25 passages were not used for studies and were
discarded. Akt phosphorylation assay. Cells were cultured in serum
free RPMI at 1ϫ106 cells/mL. After overnight culture, 2–3ϫ106
cells were treated in a 15 mL conical tube with test article for
30 min followed by IGF-1 stimulation at 0.1 μg/mL for 60 min. The
final concentration of the drug vehicle (DMSO) was 0.1%. After
treatment, cells were washed once with ice cold DPBS and lysed
with lysis buffer (20 mm Tris-HCl, pH 7.5, 140 mm NaCl, 1% NP-
40, Complete Mini Protease Inhibitor Cocktail, 10 mm NaF, 1 mm
Na3VO4, and 1 mm β-glycerol phosphate) on ice for 30 min with
vortexing every 10 min. Samples were then centrifuged at
14,000 rpm for 20 min, and supernatants were collected as total cell
lysates. Akt phosphorylation at S473 in each sample was deter-
mined by western blotting.
Water Solubility of Pelorol Analogs: Samples were weighed accu-
rately in duplicate (ca. 3 mg each) in 4 mL glass vials. The appropri-
ate amount of deionized water was added to obtain a final concen-
tration of 6 mg/mL. A stir bar was placed in the vial and the two
mixtures were stirred for 24 h, after which the samples were filtered
using a glass filter membrane. The resulting filtrate was centrifuged
in a glass conical tube for 10 min at 10,000 rpm to sediment any
precipitate that may have passed through the glass membrane. The
supernatant was sampled for HPLC analysis. The concentration
of the test compound was determined by HPLC using a six-point
standard curve of the compound prepared in methanol. Data are
summarized in Table 1.
Supporting Information (see footnote on the first page of this arti-
cle): NMR spectra for all new synthetic compounds. Evidence for
inhibition of AKT phosphorylation by (Ϯ)-28. ORTEP diagrams
for 3, 23, 25, and 28.
Western Blotting: Protein concentration in each sample was deter-
mined colorimetrically using bicinchoninic acid (BCA) assay. Ap-
proximately 15–20 μg of total protein from each sample was mixed
with 6ϫ sample loading buffer (250 mm Tris-HCl, pH 6.8, 30%
glycerol, 10% SDS, 0.012% bromophenol blue and 0.6 m DTT) and
boiled for 5 min before loading onto a polyacrylamide gel for SDS-
PAGE. Proteins from each sample were separated on a 4–12% Tris-
Glycine gel for 1.5 h with a constant voltage of 125 Volts. After
electrophoresis, proteins were transferred to a nitrocellulose mem-
brane using the iBlot Dry Transfer system (Life Technologies,
Carlsbad, CA, USA). The membrane was then blocked in 5% BSA
in PBS containing 0.1% Tween-20 (PBS-T) for 1 h at room temp.
before probing with primary antibodies overnight at 4 °C. The fol-
lowing antibodies were used: mouse anti-SHIP1 (1:500; v/v), rabbit
anti-pAkt (S473) (1:1000; v/v), rabbit anti-Akt (1:2000), and rabbit
anti-β-actin (1:2000; v/v). The membrane was then incubated with
goat anti-rabbit IgG HRP-linked or goat anti-mouse IgG HRP-
linked secondary antibodies (1:3000; v/v) for 1 h at room temp.
Target proteins on the membrane were detected with ECL solution
and exposed on a film.
Acknowledgments
Financial support was provided by the Natural Sciences and Engi-
neering Research Council of Canada (NSERC) (to R. J. A.), the
Canadian Cancer Society Research Institute (CCSRI) (to R. J. A.,
#017289), the Canadian Institutes of Heath Research (CIHR) (to
A. L. F. M., MOP-84359) and Aquinox Pharmaceuticals Inc.
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BALB/c male mice (8 weeks old) were obtained from Charles River
Laboratories (Hollister, CA, USA). Animals were acclimated for a
minimum of five days prior to the start of the study. They were
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ear with 25 ng of anti-DNP-IgE in 20 μL PBS. The left ears were
not injected and served as a negative control. 24 h post-injection,
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SHIP1-Activating Analogs of the Sponge Meroterpenoid Pelorol
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Received: May 8, 2012
Published Online: ᭿
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R. J. Andersen et al.
FULL PAPER
Natural Product Synthesis
L. G. Meimetis, M. Nodwell, L. Yang,
X. Wang, J. Wu, C. Harwig,
G. R. Stenton, L. F. Mackenzie,
T. MacRury, B. O. Patrick, A. Ming-Lum,
C. J. Ong, G. Krystal, A. L. -F. Mui,
R. J. Andersen* ............................... 1–14
Two biomimetic routes have been used to
synthesize analogs of the SHIP1-activating
sponge meroterpenoid pelorol (1) in high
ee. Resorcinol analog 18 is the most effec-
tive SHIP1-activating pelorol analog made
to date and racemic 28·HCl, an amino ana-
log, activates SHIP1 in vitro, and has effec-
tive antiinflammatory activity in a mouse
model (ED50 ≈ 0.1 mg/kg).
Synthesis of SHIP1-Activating Analogs of
the Sponge Meroterpenoid Pelorol
Keywords: Natural products / Medicinal
chemistry / Biomimetic synthesis / En-
zymes / Terpenoids / Enantioselectivity
14
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