A chiron approach to the total synthesis of cytotoxic (+)-muricatacin and (+)-5-epi-muricatacin from d-ribose

Article abstract of DOI:10.1016/j.carres.2009.09.021

A chiron approach strategy toward the total synthesis of (+)-muricatacin and (+)-5-epi-muricatacin starting from commercially available and inexpensive d-ribose through the key intermediate (S)-5-((R)-1-hydroxyallyl)furan-2(5H)-one has been disclosed.

Full text of DOI:10.1016/j.carres.2009.09.021

Carbohydrate Research 345 (2010) 41–44
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A chiron approach to the total synthesis of cytotoxic (+)-muricatacin
and (+)-5-epi-muricatacin from D-ribose q
*
Partha Ghosal, Vikas Kumar, Arun K. Shaw
Medicinal and Process Chemistry Division, Central Drug Research Institute, CSIR, Lucknow 226 001, India
a r t i c l e i n f o
a b s t r a c t
Article history:
Received 26 August 2009
Received in revised form 18 September 2009
Accepted 21 September 2009
Available online 24 September 2009
A chiron approach strategy toward the total synthesis of (+)-muricatacin and (+)-5-epi-muricatacin start-
ing from commercially available and inexpensive
D
-ribose through the key intermediate (S)-5-((R)-1-
hydroxyallyl)furan-2(5H)-one has been disclosed.
Ó 2009 Elsevier Ltd. All rights reserved.
Keywords:
D-Ribose
Muricatacin
epi-Muricatacin
1. Introduction
2
3
2
3
C12H25
1
4
C12H25
4
1
The naturally occurring c-butenolides are an emerging class of
5
5
O
O
compounds with potent antitumor, antiparasitic, and pesti-
cidalactivities. Muricatacin (1, Fig. 1), which was isolated in 1991
from the seeds of Annona muricata, is the structural prototype.1 It
shows cytotoxic activity on tumor cell lines (A-549 (lung carci-
O
O
OH
OH
(+)-epi-Muricatacin (2)
(+)-Muricatacin (1)
noma) with ED50 = 23.3 lg/mL, MCF-7 (breast carcinoma) with
Figure 1.
ED50 => 9.8
l
g/mL, and HT-29 (colon adenocarcinoma) with
ED50 = 14.0
l
g/mL). Because of its simple structure and potent bio-
logical activity, muricatacin (1) has garnered much attention from
the synthetic community. Several groups have reported the total
synthesis of (+) or (ꢀ)-muricatacin or both and also their epi-
reported total synthesis of (ꢀ)-muricatacin by desymmetrization
of dienedioate.34
mers.2–29 Cyclization of
L-glutamic acid by nitrous acid deamina-
In addition, muricatacin has also been used as the starting
material for the total synthesis of various natural products.35–42
Thus, simple structural features of muricatacin and its analogues,
along with their biological activity, motivated us to develop an effi-
cient total synthesis of this interesting natural product.
tion,2 Sharpless asymmetric dihydroxylation,3,26 epoxidation,6
acetylene–vinylidene rearrangement,8 photo-induced rearrange-
ment of epoxy diazomethyl ketones,10 enantioselective cis-dihydr-
oxylation of double bond using chiral auxiliary,14 enantioselective
1,2-addition of 2-[(trimethylsilyl)oxy]furan to aldehydes,15 ruthe-
nium-catalyzed cycloisomerization oxidation of homopropargyl
alcohols,18 Lewis acid-catalyzed ring-opening of vinyl epoxide,19
stereoselective addition of a Grignard reagent to a suitably pro-
The chiron approach is one of the most widely used approaches
toward the total synthesis of natural products in which chiral tem-
plates such as amino acids, carbohydrates, hydroxy acids, and terp-
enes are used as the starting materials.43 Over the last few years
we have been working on the synthetic development of enantio-
merically pure scaffolds by the chiron approach from commercially
available inexpensive sugars and their utilization toward the total
synthesis of natural products or natural product-like molecules.
tected a a
-hydroxy aldehyde,21 and - and a0-C–H bond functional-
ization of tetrahydrofuran24 were the major strategies used in the
total synthesis of this class of natural products. Moreover,
syntheses of 7-oxamuricatacin, b-substituted derivatives,30 and
aza-analogues31–33 have also been reported. Recently Barros et al.
44–49
In this endeavor we herein wish to report a simple and effi-
cient chiron approach synthesis of (+)-muricatacin (1) and (+)-5-
epi-muricatacin (2) starting from commercially available and inex-
q
CDRI Communication No. 7802.
pensive
D-ribose via 5-(1-hydroxyallyl)furan-2(5H)-one (7), a key
* Corresponding author.
intermediate.
E-mail address: akshaw55@yahoo.com (A.K. Shaw).
0008-6215/$ - see front matter Ó 2009 Elsevier Ltd. All rights reserved.
doi:10.1016/j.carres.2009.09.021

42
P. Ghosal et al. / Carbohydrate Research 345 (2010) 41–44
2
idene deprotection of compound 6 with trifluoroacetic acid34 gave
rise to cyclized ,b-unsaturated -lactone 7 in 79% yield (Scheme
2). It is worth mentioning here that the enantiomerically pure lac-
tone 7 is an integral structural component of an ever increasing
number of biologically and chemically significant natural products,
including many members of the annonaceous acetogenins (family
Annonaceae).35–42
3
3
2
a
c
6
C10H21
1
C12H25
1
4
4
5
5
O
O
7
O
O
OH
OH
(+)-Muricatacin (1)
8
The cross-metathesis25 of lactone 7 with 1-dodecene in the pres-
ence of Grubb’s 2nd generation catalyst delivered compound 8 that
was the precursor of (+)-5-epi-muricatacin (2). It was observed that
by increasing equivalentof 1-dodecene the yield of cross-metathesis
product was enhanced. Thus, by using 10 equiv of 1-dodecene, the
cross product 8 was obtained in 95% yield (Table 1).
2
3
MeO2C
6
1
4
D-Ribose
5
4
O
5
7
O
OP
OH
OP
7
P = Protecting group
7a
Hydrogenation of compound 8 in the presence of 10% Pd/C gave
(+)-5-epi-muricatacin (2) in 92% yield. In order to synthesize com-
pound 1, the stereochemistry of the hydroxyl group at C-5 in com-
pound 2 had to be inverted. In spite of performing hydrogenation
reaction prior to the inversion of C-5 under Mitsunobu26 condi-
tions to prevent elimination,54 the inversion was futile. Therefore,
in order to obtain the natural product 1 from 2, the latter was sub-
jected to oxidation with Dess–Martin periodinane (DMP) to deliver
the ketone which, on reduction with K-selectride, furnished com-
pound 1 with >99% selectivity and in 90% yield after two steps
(Scheme 2). The spectral data for synthetic 1 and 2 (1H and 13C
NMR, see Supplementary data) were consistent with those previ-
Scheme 1. Retrosynthesis of (+)-muricatacin.
2. Results and discussion
The retrosynthetic strategy for (+)-muricatacin (1) is depicted in
Scheme 1. We envisaged that 1 could be elaborated from lactone 8
by hydrogenation of the double bonds, followed by epimerization
at C-5. The lactone 8 was expected to be obtained from 7 by cross
metathesis with the required olefin counterpart. The synthesis of
compound 7 could be possible from diene 7a by deprotection of
protecting groups that leads to cyclization. The stereochemistry
at C4 and C5 in all these intermediates and those at C2 and C3 in
ously reported, and the optical rotation for compound 1 (½a D28
ꢁ
+22.4 (c 0.42, CHCl3, lit. ½a D20
ꢁ
+23.0 (c 1.6, CHCl3) for (+)-muricata-
cin13) and that for compound 2 (½a 2D8
ꢁ
+16.4 (c 0.3, CHCl3), lit. ½a D25
ꢁ
D
-ribose are similar. Therefore, D-ribose is the starting material of
+14.3 (c 7.4, CHCl3) for (+)-5-epi-muricatacin16) were comparable
choice for the chiron approach synthesis of both 1 and 2.
As per the retrosynthesis shown above, the synthesis of (+)-
muricatacin began with acetonide-protected methyl furanoside 4
to that reported in the literature.
derived from D
-ribose (3) in two steps.50,51 The acetonide protec-
Table 1
tion was essential here as it gives a good Z-selective Wittig prod-
uct.34,52 Zinc dust-mediated ring-opening of compound 4 under
sonication53 afforded aldehyde 5, which was used as such without
further purification. Z-Selective Wittig reaction34,52 of this crude
aldehyde with methyl (triphenylphosphoranylidene)acetate fur-
Optimization of cross-metathesis of compound 7 with 1-dodecene
Entry
Equivalent of 1-dodecene
Time (h)
Yield of 8 (%)
1
2
3
3
6
10
8
8
8
72
84
95
nished
a
,b-unsaturated ester 6 with 8.2:1 Z/E selectivity. Isopropyl-
HO
I
HO
O
O
OMe
OMe
O
1
4
OH
a
5
b
c
3
2
O
O
O
O
HO
OH
3a
3
4
CHO
MeO2C
e
f
d
O
4
4
5
5
O
O
O
O
OH
O
6
7
5
C12H25
C12H25
C10H21
g
h
O
O
O
O
O
O
OH
OH
OH
(+)-Muricatacin (1)
(+)-5-epi-muricatacin (2)
8
Scheme 2. Reagents and conditions: (a) MeOH, acetone, HCl, 55 °C, 1h (Ref. 50 or 51); (b) I2, PPh3, imidazole, PhMe–CH3CN, 0–100 °C, 5 min (Ref. 51); (c) activated Zn, THF,
H2O, sonication, 50 °C, 3 h; (d) Ph3PCHCO2Me, dry MeOH, 0 °C, 12 h, 62% over two steps; (e) TFA, THF, H2O, 65 °C, 2 h, 79%; (f) Grubbs 2nd generation catalyst, 1-dodecene
(10 equiv), dry DCM, 12 h, 95%; (g) H2, Pd/C, MeOH, 6 h, 92%; and (h) (i) DMP, dry DCM, 0 °C to rt; (ii) K-Selectride, THF, ꢀ78 °C, 2 h, 90%.

P. Ghosal et al. / Carbohydrate Research 345 (2010) 41–44
43
(dd, 1H, J 1.5, 11.6 Hz), 6.17 (dd, 1H, J 7.5, 11.8 Hz); 13C NMR
(50 MHz, CDCl3): d 25.5 (CH3), 28.2 (CH3), 51.8 (CH3), 76.0 (CH),
80.0 (CH), 109.5 (qC), 118.1 (CH2), 121.3 (CH), 134.3 (CH), 147.1
(CH), 166.3 (C@O); DART–HRESIMS: Calcd for C11H17O4 [MꢀH]+:
m/z 213.1127; found m/z 213.1143.
3. Conclusions
In summary, we have achieved a short and efficient route for
the total synthesis of (+)-muricatacin and (+)-5-epi-muricatacin
starting from
stereochemistry inherited from C2 and C3 of
D
-ribose through a key intermediate, lactone 7. The
-ribose at C4 and
D
4.3. (5S)-5-((R)-1-Hydroxyallyl)furan-2(5H)-one (7)
C5 was translated to the desired stereochemistry of the C12 side
chain of 2. The highly functionalized stereochemically pure lactone
7 should find wide applications as a scaffold toward the syntheses
of simple and complex oxygenated alkylbutyrolactone natural
products in general and acetogenin derivatives in particular. It
has been reported that the activity of this natural product is af-
fected by the side chain;55 therefore, by using different cross olefin
counterparts, various analogues of muricatacin might be synthe-
sized. Work in this direction is underway in our laboratory.
Compound 6 (800 mg, 3.77 mmol) dissolved in 15 mL of 4:1
THF–H2O was heated at 65 °C with 3 mL of CF3CO2H. After comple-
tion of reaction (TLC, 2 h), the reaction was quenched with satd aq
NaHCO3, and the product was extracted with EtOAc (3 ꢂ 30 mL).
The combined organic layers were dried over anhydrous Na2SO4
and concentrated under reduced pressure to give a residue that
was purified by flash column chromatography to afford compound
7 (418 mg, 79%) as a light-yellow oil. Eluent for column chroma-
tography: 1:14 EtOAc–hexane (v/v); ½a D28
ꢀ488 (c 0.53, CHCl3); Rf
ꢁ
4. Experimental
4.1. General
0.38 (1:1 EtOAc–hexane); IR (Neat, cmꢀ1): 3449, 3021, 2359,
1756, 1597, 1216, and 1042; 1H NMR (300 MHz, CDCl3): d 3.89
(br s, 1H), 4.44 (t, 1H, J 4.4 Hz), 4.99–5.02 (m, 1H), 5.23–5.29 (m,
1H), 5.37–5.43 (m, 1H), 5.79–5.93 (m, 1H), 6.13 (dd, 1H, J 2.0,
Organic solvents were dried by standard methods. All the prod-
ucts were characterized by 1H, 13C, two-dimensional homonuclear
COSY (correlation spectroscopy), IR, and ESIMS. Analytical TLC was
performed using 2.5 ꢂ 5 cm plates coated with a 0.25 mm thick-
ness of silica gel (60F-254), and visualization was accomplished
with CeSO4 (1% in 2 N H2SO4) and subsequent charring over a hot
plate. Column chromatography was performed using silica gel
(100–200 and 230–400 mesh). NMR spectra were recorded on Bru-
ker Avance DPX 200FT, Bruker Robotics, and Bruker DRX 300 Spec-
trometers at 200 and 300 MHz (1H) and 50 and 75 MHz (13C),
respectively. Experiments were recorded in CDCl3 and CD3OD at
25 °C. Chemical shifts are given on the d scale and are referenced
to the TMS at 0.00 ppm for 1H and 0.00 ppm for 13C. For 13C NMR
reference CDCl3 appeared at 77.4 ppm. IR spectra were recorded
on Perkin–Elmer 881 and FTIR-8210 PC Shimadzu spectrophotom-
eters. Mass spectra were recorded on a JEOLJMS-600H high-resolu-
tion spectrometer in the electron-impact (EI) mode at 70 eV, or on
a JEOL Accutof-DART instrument in the electrospray-ionization
(ESI, positive-ion) DART mode. Optical rotations were determined
on an Autopol III polarimeter using a 1-dm cell at 28 °C in chloro-
form as the solvent; concentrations indicated are in g/100 mL.
5.8 Hz), 7.47 (dd, 1H,
J
1.4, 5.8 Hz); 13C NMR (75 MHz,
CDCl3 + CCl4): d 72.0 (CH), 86.2 (CH), 118.4 (CH2), 123.3 (CH),
135.2 (CH), 153.9 (CH), 173.7 (C@O); HREIMS: Calcd for C7H9O3
[MꢀH]+: m/z 141.0552; found m/z 141.0525.
4.4. (5S)-5-((R, Z)-1-Hydroxytridec-2-enyl)furan-2(5H)-one (8)
To a 50-mL two-necked oven-dried round-bottomed flask fitted
with a reflux condenser and septum was added Grubbs 2nd genera-
tion catalyst (16 mg, 0.018 mmol) under an argon atmosphere. Dry
degassed CH2Cl2 (5 mL) was then added to the above-mentioned
solution through a syringe, and the solution was kept stirring. Com-
pound 7 (100 mg, 0.71 mmol) and 1-dodecene (1.2 g, 7.1 mmol) in
DCM (2 mL each) were added through a syringe to the stirring solu-
tion. The septum was replaced with a glass stopper while the stirring
was continued. The solution was refluxed for 12 h. The mixture was
cooled slowly to room temperature. The organic solvent was then
evaporated under reduced pressure to give a black residue that
was purified by column chromatography to give 8 as a semisolid
compound (195 mg, 95%). Eluent for column chromatography: 1:7
EtOAc–hexane (v/v); ½a D28
ꢀ154 (c 0.43, CHCl3); Rf 0.50 (1:1 EtOAc–
ꢁ
hexane); IR (KBr, cmꢀ1): 3442, 3021, 2927, 2858, 2362, 1755, 1604,
1217, 1042; 1H NMR (300 MHz, CDCl3): d 0.88 (t, 3H, J 6.0 Hz), 1.26
(m, 14H), 1.32–1.38 (m, 2H), 2.06 (dd, 2H, J 6.8, 13.7 Hz), 4.37 (t,
1H, J 5.2 Hz), 4.94–4.97 (m, 1H), 5.47 (dd, 1H, J 6.2, 15.5 Hz), 5.79–
5.86 (m, 1H), 6.16 (dd, 1H, J 1.9, 5.7 Hz), 7.47(dd, 1H, J 1.4, 5.8 Hz);
13C NMR (75 MHz, CDCl3 + CCl4): d 14.6 (CH3), 23.2 (CH2), 29.4–
30.1 (6 ꢂ CH2), 32.4 (CH2), 32.8 (CH2), 72.3 (CH), 86.3 (CH), 123.5
(CH), 126.8 (CH), 135.9 (CH), 153.6 (CH), 173.1 (C@O); HREIMS:
Calcd for C17H27O3 [MꢀH]+: m/z 279.1960; found m/z 279.1946.
4.2. (Z)-Methyl 3-((4S,5R)-2,2-dimethyl-5-vinyl-1,3-dioxolan-4-
yl)acrylate (6)
To a solution of the iodofuranoside 4 (1.0 g, 3.18 mmol) in
10 mL of THF (with two drops of water) was added 2.0 g of zinc
preactivated with 2 N HCl. The reaction mixture was sonicated at
50 °C for 3 h. After completion of the reaction, it was filtered
through a Celite pad, washed twice with EtOAc, and the filtrate
was concentrated under reduced pressure at low temperature to
give the labile aldehyde 5, which was immediately used for the
next step without further purification. The crude aldehyde 5 was
dissolved in 50 mL of dry MeOH under an argon atmosphere and
cooled to 0 °C. Methyl (triphenylphosphoranylidene)acetate
(1.67 g, 5 mmol) was added portionwise to aldehyde 5, and the
reaction mixture was stirred at 0 °C for 12 h. After completion of
the reaction, the organic solvent was evaporated to give a residue
that was purified by flash column chromatography to furnish com-
pound 6 (420 mg, 62% over two steps).
4.5. (+)-5-epi-Muricatacin (2)
A catalytic amount of 10% Pd/C (20 mg) was added to a solution
of 8 (195 mg, 0.696 mmol) in MeOH (10 mL). A vacuum was cre-
ated in a round-bottomed flask containing the above-mentioned
reaction mixture with the help of a pump, and the mixture was left
stirring under H2 in a balloon at 1 atmosphere. After completion of
the reaction (TLC control, 6 h), the catalyst was removed by filtra-
tion, washed twice with MeOH and the combined filtrate was con-
centrated to afford a solid residue that was purified by column
chromatography to give 2 (182 mg, 0.64 mmol, 92%) as a white so-
lid: (mp 71–73 °C), (lit. mp 70–72 °C).26 Eluent for column chroma-
Eluent for column chromatography: 1:4 EtOAc–hexane (v/v);
½
a 2D8
+224 (c 0.16, CHCl3); Rf 0.59 (1:9, EtOAc–hexane); IR (Neat,
ꢁ
cmꢀ1): 3021, 2360, 1720, 1601, 1216, 1046; 1H NMR (200 MHz,
CDCl3): d 1.38 (s, 3H, CH3), 1.51 (s, 3H, CH3), 3.68 (s, 3H, CH3),
4.84 (t, 1H, J 7.0 Hz), 5.08–5.29 (m, 2H), 5.54–5.71 (m, 2H), 5.86
tography: 1:7 EtOAc–hexane (v/v); ½a D28
ꢁ
+16.6 (c 0.078, CHCl3), lit.
½
a 2D5 +14.3 (c 7.4, CHCl3);16 Rf 0.5 (1:1 EtOAc–hexane); IR (KBr,
ꢁ

44
P. Ghosal et al. / Carbohydrate Research 345 (2010) 41–44
cmꢀ1): 3401, 3021, 2926, 2359, 1768, 1598, 1216, 1040; 1H NMR
(300 MHz, CDCl3): d 0.87 (t, 3H, J 13.2 Hz), 1.25 (m, 19H), 1.38–
1.42 (m, 2H), 1.50 (d, 1H, J 6.8 Hz), 2.10–2.30 (m, 2H), 2.49–2.60
(m, 2H), 3.89–3.94 (m, 1H), 4.40–4.46 (m, 1H); 13C NMR
(75 MHz. CDCl3): d 14.0 (CH3), 20.9 (CH2), 22.6 (CH2), 25.5 (CH2),
28.6 (CH2), 29.2 (CH2), 29.4–29.5 (6 ꢂ CH2), 31.8 (2 ꢂ CH2), 71.2
(CH), 82.8 (CH), 177.4 (C@O); DART–HRESIMS: Calcd for
C17H33O3 [M+H]+: m/z 285.2429; found m/z 285.2425.
5. Tochtermann, W.; Scholz, G.; Bunte, G.; Wolff, C.; Peters, E.-M.; Peters, K.; Von
Schnering, H. G. Liebigs Ann. Chem. 1992, 1069–1080.
6. Saïah, M.; Bessodes, M.; Antonakis, K. Tetrahedron Lett. 1993, 34, 1597–1598.
7. Marshall, J. A.; Welmaker, G. S. J. Org. Chem. 1994, 59, 4122–4125.
8. Quayle, P.; Rahman, S.; Herbert, J. Tetrahedron Lett. 1995, 36, 8087–8088.
9. Sanière, M.; Charvet, I.; Le Merrer, Y.; Depezay, J.-C. Tetrahedron 1995, 51,
1653–1662.
10. Van Aar, M. P. M.; Thijs, L.; Zwanenburg, B. Tetrahedron 1995, 51, 11223–11234.
11. Somfai, P. J. Chem. Soc., Perkin Trans. 1 1995, 817–819.
12. Bonini, C.; Federici, C.; Rossi, L.; Righi, G. J. Org. Chem. 1995, 60, 4803–4812.
13. Rassu, G.; Pinna, L.; Spanu, P.; Zanardi, F.; Battistini, L.; Casiraghi, G. J. Org.
Chem. 1997, 62, 4513–4517.
4.6. (+)-Muricatacin (1)
14. Chang, S.-W.; Hung, C.-Y.; Liu, H.-H.; Uang, B.-J. Tetrahedron: Asymmetry 1998,
9, 521–529.
15. Szlosek, M.; Franck, X.; Figadère, B.; Cavé, A. J. Org. Chem. 1998, 63, 5169–5172.
16. Yoon, S.-H.; Moon, H.-S.; Hwang, S.-K.; Choi, S. R.; Kang, S.-K. Bioorg. Med. Chem.
1998, 6, 1043–1049.
17. Couladouros, E. A.; Mihou, A. P. Tetrahedron Lett. 1999, 40, 4861–4862.
18. Trost, B. M.; Rhee, Y. H. J. Am. Chem. Soc. 1999, 121, 11680–11683.
19. Baylon, C.; Prestat, G.; Heck, M.-P.; Mioskowski, C. Tetrahedron Lett. 2000, 41,
3833–3835.
20. Chandrasekhar, M.; Chandra, K. L.; Singh, V. K. Tetrahedron Lett. 2002, 43, 2773–
2775.
21. Carda, M.; Rodríguez, S.; González, F.; Castillo, E.; Villanueva, A.; Marco, J. A.
Eur. J. Org. Chem. 2002, 2649–2655.
To an ice cooled solution of 2 (51 mg, 0.18 mmol) in dry DCM
(6 mL) was added Dess–Martin periodinane (115 mg, 0.27 mmol),
and the reaction mixture was allowed to stir for 1.5 h. The resulting
mixture was dilutedwith satd aq NaHCO3 and 10% aq Na2S2O3. It was
stirred for another 30 min and then extracted with CH2Cl2
(3 ꢂ 10 mL). The combined organic layer was dried (Na2SO4) and
concentrated under reduced pressure to afford the desired ketolac-
tone, a solid residue. The solid, without further purification was
taken in a 50-mL two-necked oven-dried round-bottomed flask in
dry THF (5 mL) at ꢀ78 °C, and theketo group was selectively reduced
by K-Selectride (0.2 mL 1 N solution in THF, 1.1 equiv) under an ar-
gon atmosphere. After completion of reaction (TLC control, 2 h), satd
aq NH4Cl was added, and the resulting solution was extracted with
EtOAc (3 ꢂ 15 mL). The combined organic layer was dried (Na2SO4)
and concentrated in vacuo to a residue that was purified by column
chromatography to give pure compound 1 as a white solid material
(46 mg, 0.16 mmol, 90%): mp 68–70 °C, (lit. mp 68–70 °C).26 Eluent
´
22. Popsavin, V.; Krstic, I.; Popsavin, M. Tetrahedron Lett. 2003, 44, 8897–8900.
23. Raghavan, S.; Joseph, S. C. Tetrahedron: Asymmetry 2003, 14, 101–105.
24. Yoshimitsu, T.; Makino, T.; Nagaoka, H. J. Org. Chem. 2003, 68, 7548–7550.
25. Quinn, K. J.; Isaacs, A. K.; Arvary, R. A. Org. Lett. 2004, 6, 4143–4145.
26. Ahmed, M. M.; Cui, H.; O’Doherty, G. A. J. Org. Chem. 2006, 71, 6686–6689.
27. Prasad, K. R.; Anbarasan, P. Tetrahedron: Asymmetry 2006, 17, 2465–2467.
28. Ito, M.; Osaku, A.; Shiibashi, A.; Ikariya, T. Org. Lett. 2007, 9, 1821–1824.
29. Prasad, K. R.; Gandi, V. Tetrahedron: Asymmetry 2008, 19, 2616–2619.
30. Navarro, C.; Moreno, A.; Csákÿ, A. G. J. Org. Chem. 2009, 74, 466–469.
31. Baussanne, I.; Schwardt, O.; Royer, J.; Pichon, M.; Figadère, B.; Cavé, A.
Tetrahedron Lett. 1997, 38, 2259–2262.
32. Pichon, M.; Jullian, J.-C.; Figadère, B.; Cavé, A. Tetrahedron Lett. 1998, 39, 1755–
1758.
33. Andrés, J. M.; de Elena, N.; Pedrosa, R.; Pérez-Encabo, A. Tetrahedron:
Asymmetry 2001, 12, 1503–1509.
34. Barros, M. T.; Charmier, M. A. J.; Maycock, C. D.; Michaud, T. Tetrahedron 2009,
65, 396–399.
35. Konno, H.; Makabe, H.; Tanaka, A.; Oritani, T. Tetrahedron Lett. 1996, 37, 5393–
5396.
36. Makabe, H.; Tanaka, A.; Oritani, T. Tetrahedron Lett. 1997, 38, 4247–4250.
37. Makabe, H.; Tanaka, A.; Oritani, T. Tetrahedron 1998, 54, 6329–6340.
38. Sinha, S. C.; Sinha, S. C.; Keinan, E. J. Org. Chem. 1999, 64, 7067–7073.
39. Szlosek, M.; Peyrat, J.-F.; Chaboche, C.; Franck, X.; Hocquemiller, R.; Figadère, B.
New J. Chem. 2000, 24, 337–342.
40. Yoshimitsu, T.; Makino, T.; Nagaoka, H. J. Org. Chem. 2004, 69, 1993–1998.
41. Makabe, H. Biosci. Biotechnol. Biochem. 2007, 71, 2367–2374.
42. Konno, H.; Okuno, Y.; Makabe, H.; Nosaka, K.; Onishi, A.; Abe, Y.; Sugimoto, A.;
Akaji, K. Tetrahedron Lett. 2008, 49, 782–785.
for column chromatography: 1:7 EtOAc–hexane (v/v); ½a D28
ꢁ
+22.4
(c 0.42, CHCl3), lit. ½a D20
ꢁ
+23.0 (c 1.6, CHCl3)13; Rf 0.46 (1:1EtOAc–hex-
ane); IR (KBr, cmꢀ1): 3417, 2925, 2855, 2360, 1751, 1664, 1596,
1197, 1101; 1H NMR (300 MHz, CDCl3): d 0.88 (t, 3H, J 6.3 Hz.),
1.26 (m, 19H) 1.52 (s, 3H), 2.04–2.29 (m, 2H), 2.46–2.67 (m, 2H),
3.52–3.58 (m, 1H), 4.38–4.44 (m, 1H); 13C NMR (75 MHz, CDCl3): d
14.1 (CH3), 22.6 (CH2), 24.1 (CH2), 25.4 (CH2), 28.7 (CH2), 29.3
(CH2), 29.5–29.6 (6 ꢂ CH2), 31.9 (CH2), 32.9 (CH2), 73.6 (CH), 82.9
(CH), 177.2 (C@O); DART–HRESIMS: Calcd for C17H33O3 [M+H]+: m/
z 285.2430; found m/z 285.2399.
Acknowledgments
43. Hanessian, S. Total Synthesis of Natural Products; The ‘Chiron’ Approach;
Pergamon: Oxford, 1983.
44. Reddy, L. V. R.; Roy, A. D.; Roy, R.; Shaw, A. K. Chem. Commun. (Cambridge) 2006,
3444–3446.
45. Reddy, L. V. R.; Reddy, P. V.; Shaw, A. K. Tetrahedron: Asymmetry 2007, 18, 542–
546.
We are thankful to Anup K. Pandey for technical assistance, and
SAIF, CDRI, for providing spectral data. P.G. and V.K. thank CSIR,
New Delhi, for financial support.
46. Kumar, V.; Gauniyal, H. M.; Shaw, A. K. Tetrahedron: Asymmetry 2007, 18, 2069–
2078.
Supplementary data
47. Kumar, V.; Shaw, A. K. J. Org. Chem. 2008, 73, 7526–7531.
48. Pal, P.; Kumar, B.; Shaw, A. K. Eur. J. Org. Chem. 2009, 2179–2184.
49. Saquib, M.; Husain, I.; Kumar, B.; Shaw, A. K. Chem. Eur. J. 2009, 15, 6041–
6049.
50. Ali, S. M.; Ramesh, K.; Borchardt, R. T. Tetrahedron Lett. 1990, 31, 1509–1512.
51. Wender, P. A.; Bi, F. C.; Buschmann, N.; Gosselin, F.; Kan, C.; Kee, J.-M.; Ohmura,
H. Org. Lett. 2006, 8, 5373–5376.
52. Minami, N.; Ko, S. S.; Kishi, Y. J. Am. Chem. Soc. 1982, 104, 1109–1111.
53. Hyldtoft, L.; Poulsen, C. S.; Madsen, R. Chem. Commun. (Cambridge) 1999, 2101–
2102.
54. Ahmed, M. M.; Akhmedov, N. G.; Cui, H.; Friedrich, D.; O’Doherty, A.
Heterocycles 2006, 70, 223–233.
Supplementary data (1H and 13C NMR spectra of all compounds)
associated with this article can be found, in the online version, at
doi:10.1016/j.carres.2009.09.021.
References
1. Rieser, M. J.; Kozlowski, J. F.; Wood, K. V.; McLaughlin, J. L. Tetrahedron Lett.
1991, 32, 1137–1140.
2. Figadère, B.; Harmange, J.-C.; Laurens, A.; Cavé, A. Tetrahedron Lett. 1991, 32,
7539–7542.
3. Wang, Z.-M.; Zhang, X.-L.; Sharpless, K. B.; Sinha, S. C.; Sinha-Bagchi, A.; Keinan,
E. Tetrahedron Lett. 1992, 33, 6407–6410.
4. Marshall, J. A.; Welmaker, G. S. Synlett 1992, 537–538.
55. Cavé, A.; Chaboche, C.; Figadére, B.; Harmange, J. C.; Laurens, A.; Peyrat, J. F.;
Pichon, M.; Szlosek, M.; Cotte-Lafitte, J.; Quéro, A. M. Eur. J. Med. Chem. 1997,
32, 617–623.