A short synthesis of optically active corey lactone by means of the dirhodium(II)-catalyzed intramolecular C-H insertion reaction of an α-diazo ketone

Article abstract of DOI:10.1055/s-1998-2095

Optically active Corey lactone 8 has been synthesized using a dirhodium(II)-catalyzed intramolecular C-H insertion reaction of chiral α- diazo-β-oxo ester 2 as a key step.

Full text of DOI:10.1055/s-1998-2095

SYNTHESIS
July 1998
973
A Short Synthesis of Optically Active Corey Lactone by Means of the Dirhodium(II)-
Catalyzed Intramolecular CÐH Insertion Reaction of an α-Diazo Ketone
Takayuki Yakura, Seiji Yamada, Miki Azuma, Akiharu Ueki, Masazumi Ikeda*
Kyoto Pharmaceutical University, Misasagi, Yamashina, Kyoto 607, Japan
Fax +81(75)5954763
Received 4 November 1997; revised 8 January 1998
Abstract: Optically active Corey lactone 8 has been synthesized
using a dirhodium(II)-catalyzed intramolecular C–H insertion
reaction of chiral α-diazo-β-oxo ester 2 as a key step.
Key words: dirhodium(II)-catalyzed intramolecular C–H inser-
tion, α-diazo ketone, 2-oxocyclopentanecarboxylate, Corey lac-
tone, dirhodium(II) tetraacetate
Corey lactone and its derivatives are versatile intermedi-
ates for the synthesis of prostaglandins and their ana-
logs.1–6 Herein, we describe a short and facile synthesis of
optically active Corey lactone 8 as an application of our
recently developed diastereoselective dirhodium(II)-cata-
lyzed intramolecular C–H insertion reaction of α-diazo-β-
oxo esters.7–9
Our synthesis started from known optically active alde-
hyde, (–)-(R)-3-(tert-butyldimethylsilyloxy)hept-6-enal
(1),10 which is readily available by enzymatic reduction of
potassium 3-oxohept-6-enoate, followed by protection of
the resultant secondary hydroxy group with silyl group
and subsequent reduction with diisobutylaluminum hy-
dride (DIBAL-H) in toluene. Homologation of 1 with me-
thyl diazoacetate11 and diazo transfer reaction produced
α-diazo-β-oxo ester 2 in 68% yield. Treatment of 2 with
1 mol% of dirhodium(II) tetraacetate [Rh2(OAc)4] in
dichloromethane under reflux7 for 15 minutes afforded a
80:20 mixture of (1R,2R,3S)-cyclopentanecarboxylate 3
and its (1S,2S,3S)-isomer 4 in 75% yield, from which pure
3 was obtained in 50% yield after chromatographic puri-
fication.12
Reduction of 3 with lithium aluminum hydride in THF at
room temperature proceeded in a stereoselective manner
to give diol 5, as a result of attack of hydride ion on the
less hindered Si-face of the ketonic carbonyl group. When
DIBAL-H was used as a reducing agent, the stereoselec-
tivity was reduced to 3:1. The selective protection of the
primary hydroxy group in 5 with tert-butyldiphenylsilyl
group followed by acylation of the secondary hydroxy
Mps were determined using a Yanaco micro melting point apparatus
and are uncorrected. IR spectra were recorded on a JASCO IR-1 spec-
1
group of the resulting 6 with p-phenylbenzoyl chloride
(PPB-Cl) and pyridine in the presence of 4-(dimethylami-
no)pyridine gave PPB-ester 7. Oxidation–lactonization of
7 was accomplished by treatment with a catalytic amount
of ruthenium(III) chloride and sodium periodate in carbon
tetrachloride/acetonitrile/water (1:1:1)13 at room tempera-
ture, followed by desilylation with 10% HCl to give Corey
lactone 8 in 53% yield, whose spectroscopic data and spe-
cific rotation were identical with those of an authentic
sample.4
trophotometer for solutions in CCl4. H NMR spectra (300 MHz)
were determined with a Varian XL-300 spectrometer for solutions in
CDCl3. δ-Values quoted are relative to TMS. Specific rotations were
recorded on a JASCO DIP-360 polarimeter in CHCl3. Column chro-
matography was performed on silica gel 60 PF254 (Nacalai Tesque,
Inc.) under pressure.
(–)-Methyl (R)-5-(tert-Butyldimethylsilyloxy)-2-diazo-3-oxonon-
8-enoate (2):
According to the procedure of Holmquist and Roskamp,11 a solution
of 110 {[α]D26 +0.85 (c = 1.05), lit.10 [α]D25 +0.84 (c = 1.43, CHCl3),
1.38 g, 6.44 mmol} was added to a suspension of methyl diazoacetate
(709 mg, 7.08 mmol) and SnCl2 (121 mg, 0.64 mmol) in CH2Cl2
(35 mL) at r.t. The mixture was stirred for 1 h and concentrated. The
In summary, we succeeded in the synthesis of Corey lac-
tone 8 in 18% overall yield and in 6 steps from 2.

SYNTHESIS
Short Papers
974
residue was chromatographed on silica gel (hexane/EtOAc 80:1) to
give (–)-methyl (R)-5-(tert-butyldimethylsilyloxy)-3-oxonon-8-
enoate14 as a colorless oil; yield: 1.48 g (73%); [α]D26 –17.9 (c = 1.01).
A solution of the thus obtained oxo ester (1.29 g, 4.09 mmol), Et3N
(826 mg, 8.18 mmol), and p-toluenesulfonyl azide (968 mg,
4.91 mmol) in MeCN (40 mL) was stirred at r.t. for 36 h and then di-
luted with Et2O (50 mL). The mixture was washed with 9% aq KOH
(20 mL) and brine, dried (MgSO4), and concentrated. The residue was
chromatographed on silica gel (hexane/EtOAc 50:1) to give 214 as a
pale yellow oil; yield: 1.29 g (93%); [α]D27 –26.3 (c = 1.23).
(m, 2H, =CH2), 5.51 (ddd, 1H, J = 8.1, 5.4, 2.7 Hz, 1-H), 5.72–5.87
(m, 1H, CH=), 7.30–7.51 (m, 9H, ArH), 7.62–7.69 (m, 8H, ArH),
8.08–8.13 (m, 2H, ArH).
Anal. Calcd for C44H56O4Si2: C, 74.95; H, 8.01. Found: C, 74.98; H,
8.13.
(–)-[3aR-(3aα,4α,5â,6aα)]-Hexahydro-4-hydroxymethyl-2-oxo-
2H-cyclopenta[b]furan-5-yl 1,1'-Biphenyl-4-carboxylate (8):
A suspension of 7 (295 mg, 0.42 mmol), NaIO4 (449 mg, 2.10 mmol),
and RuCl3•xΗ2O (1 mg) in CCl4/MeCN/H2O (1:1:1, 15 mL) was
stirred at r.t. for 5.5 h. The mixture was extracted with Et2O (3 ×
10 mL) and the extracts were dried (MgSO4), and concentrated. The
residue was dissolved in MeOH (10 mL) and 10% HCl (3 mL) was
added to this mixture. The resultant mixture was stirred at r.t. for 15 h
and was diluted with H2O (20 mL) and then was extracted with EtOAc
(3 × 20 mL). The extracts were washed with sat. aq NaHCO3 (10 mL),
dried (MgSO4), and concentrated. The residue was chromatographed
on silica gel (hexane/EtOAc 1:1) to give 8 as colorless plates; yield:
76 mg (53%); mp 130.5–132.0 ˚C (CH2Cl2/hexane); [α]D26 –86.9 (c =
1.19); {lit.4 mp 130–131 ˚C; [α]D –87.3 (c = 1.0, CHCl3)}.
(–)-Methyl (1R,2R,3S)-3-(tert-Butyldimethylsilyloxy)-5-oxo-2-
(prop-2-enyl)cyclopentanecarboxylate (3):
A solution of 2 (848 mg, 2.49 mmol) in CH2Cl2 (10 mL) was added
to a boiling solution of Rh2(OAc)4 (9 mg, 0.02 mmol) in CH2Cl2
(90 mL) and the mixture was refluxed for 15 min. After evaporation
of the solvent, the crude material was chromatographed on silica gel
(hexane/EtOAc 10:1) to give a 80:20 mixture of 3 and its (1S,2S,3S)-
isomer 4 as a colorless oil; yield: 584 mg (75%). The mixture was re-
chromatographed on silica gel (hexane/EtOAc 80:1) to give pure 314
as a colorless oil; yield: 389 mg (50%); [α]D25 –28.3 (c = 0.93).
IR: ν = 3800–3300, 1770, 1710 cm–1.
1H NMR: δ = 2.22–2.31 (m, 1H), 2.36–2.45 (m, 4H), 2.86–2.98 (m,
2H, 3-H2), 3.62–3.79 (m, 2H, CH2O), 5.08 (td, 1H, J = 6.1, 1.7 Hz,
6a-H), 5.42 (dt, 1H, J = 6.3, 4.3 Hz, 5-H), 7.36–7.50 (m, 3H, ArH),
7.59–7.69 (m, 4H, ArH), 8.04–8.09 (m, 2H, ArH).
(+)-(1R,2S,3R,4S)-4-(tert-Butyldimethylsilyloxy)-2-[(tert-butyl-
diphenylsilyloxy)methyl]-3-(prop-2-enyl)cyclopentanol (6):
A solution of 3 (377 mg, 1.21 mmol) in THF (7 mL) was added to a
suspension of LiAlH4 (184 mg, 4.84 mmol) in THF (18 mL) at 0°C
under N2. After the mixture had been stirred at r.t. for 1 h, 5% aq
NaOH (1 mL) was added to the mixture. The resulting mixture was
dried (MgSO4) and concentrated to give crude (+)-(1S,2R,3S,5R)-3-
(tert-butyldimethylsilyloxy)-5-hydroxy-2-(prop-2-enyl)cyclopentane-
methanol (5) (271 mg, 78%), which was used without further purifi-
cation in the next step. A mixture of the crude 5 (141 mg, 0.49 mmol),
TBDPS-chloride (71 mg, 0.99 mmol), Et3N (111 mg, 1.10 mmol),
and DMAP (4 mg, 0.03 mmol) in CH2Cl2 (10 mL) was stirred at r.t.
for 27 h. The mixture was diluted with Et2O (30 mL) and washed with
sat. aq NH4Cl (10 mL), dried (MgSO4), and concentrated. The residue
was chromatographed on silica gel (hexane/EtOAc 3:1) to give 6 as a
colorless oil; yield: 249 mg (76% from 3); [α]D24 +25.3 (c = 1.26).
IR: ν = 3700–3500 cm–1.
Anal. Calcd for C21H20O5: C, 71.58; H, 5.72. Found: C, 71.77; H, 5.72.
(1) Corey, E. J.; Weinshenker, N. M.; Schaaf, T. K.; Huber, W.
J. Am. Chem. Soc. 1969, 91, 5675.
(2) Corey, E. J.; Schaaf, T. K.; Huber, W.; Koelliker, U.; Weinshen-
ker, N. M. J. Am. Chem. Soc. 1970, 92, 397.
(3) Corey, E. J.; Shirahama, H.; Yamamoto, H.; Terashima, S.;
Venkateswarlu, A.; Schaaf, T. K. J. Am. Chem. Soc. 1971, 93,
1490.
(4) Corey, E. J.; Albonico, S. M.; Koelliker, U.; Schaaf, T. K.; Var-
ma, R. K. J. Am. Chem. Soc. 1971, 93, 1491.
(5) For reviews, see: Roberts, S. M.; Scheinmann, F. New Synthetic
Routes to Prostaglandins and Thromboxanes; Academic Press:
1982.
1H NMR: δ = 0.08 (s, 3H, SiMe), 0.11 (s, 3H, SiMe), 0.91 (s, 9H, t-
Bu), 1.04 (s, 9H, t-Bu), 1.71–1.97 (m, 4H, 2-H, 3-H, and 5-H2), 2.04-
2.14 (m, 1H, one of CH2CH=), 2.25–2.37 (m, 1H, one of CH2CH=),
2.94 (d, 1H, J = 10.0 Hz, 1-OH), 3.53 (dd, 1H, J = 10.1, 5.5 Hz, one
of CH2O), 3.84 (dd, 1H, J = 10.1, 4.1 Hz, one of CH2O), 4.12–4.21
(m, 1H, 1-H), 4.25–4.31 (m, 1H, 4-H), 4.87–5.04 (m, 2H, =CH2),
5.62–5.77 (m, 1H, CH=), 7.34–7.46 (m, 6H, ArH), 7.62–7.68 (m, 4H,
ArH).
Collins, P. W.; Djuric, S. W. Chem. Rev. 1993, 93, 1533.
(6) A recent report on the synthesis of the optically active Corey
lactone: Node, M.; Nakamura, D.; Nishide, K.; Inoue, T. Hete-
rocycles 1997, 46, 535, and references cited therein.
(7) Yakura, T.; Yamada, S.; Kunimune, Y.; Ueki, A.; Ikeda, M.
J. Chem. Soc., Perkin Trans. 1 1997, 3643.
Yakura, T.; Yamada, S.; Ueki, A.; Ikeda, M. Synlett 1997, 185.
(8) Taber, D. F.; Song, Y. J. Org. Chem. 1997, 62, 6603.
Taber, D. F.; You, K. K.; Rheingold, A. L. J. Am. Chem. Soc.
1996, 118, 547, and references cited therein.
Anal. Calcd for C31H48O3Si2: C, 70.94; H, 9.22. Found: C, 71.20; H,
9.37.
(9) For recent reviews of Rh(II)-catalyzed reactions, see: Doyle, M.
P. Aldrichimica Acta 1996, 29, 3.
(+)-(1R,2S,3R,4S)-4-(tert-Butyldimethylsilyloxy)-2-[(tert-butyl-
diphenylsilyloxy)methyl]-3-(prop-2-enyl)cyclopentyl 1,1'-Bi-
phenyl-4-carboxylate (7):
Hashimoto, S.; Watanabe, N.; Anada, M.; Ikegami, S. J. Synth.
Org. Chem., Jpn. 1996, 54, 988.
A mixture of 6 (240 mg, 0.46 mmol), 4-phenylbenzoyl chloride
(199 mg, 0.92 mmol), and DMAP (1 mg, 0.005 mmol) in pyridine
(10 mL) was heated at 100°C for 2.5 h. After the mixture had been
cooled to r.t., MeOH (5 mL) was added. The resulting mixture was
stirred for a further 10 min. The mixture was diluted with EtOAc (30
mL) and washed with 10% HCl (10 mL), dried (MgSO4), and concen-
trated. The residue was chromatographed on silica gel (hexane/
EtOAc 50:1) to give 7 as a colorless oil; yield: 295 mg (91%); [α]D25
+19.2 (c = 1.28).
(10) Hayakawa, K.; Nagatsugi, F.; Kanematsu, K. J. Org. Chem.
1988, 53, 860.
(11) Holmquist, C. R.; Roskamp, E. J. J. Org. Chem. 1989, 54, 3258.
(12) In practice, it is not necessary to separate the two isomers 3 and
4 at this stage. The mixture of 3 and 4 was converted into 8 in
18% overall yield from α-diazo ketone 2. The oxidation of the
(2S,3S,4S)-isomer of 7 derived from 4 gave the corresponding
carboxylic acid which could be easily removed by washing with
a weak base solution.
IR: ν = 1710 cm–1.
(13) Carlsen, P. H. J.; Katsuki, T.; Martin, V. S.; Sharpless, K. B.
J. Org. Chem. 1981, 46, 3936.
1H NMR: δ = 0.02 (s, 3H, SiMe), 0.06 (s, 3H, SiMe), 0.89 (s, 9H, t-
Bu), 1.04 (s, 9H, t-Bu), 1.85–2.42 (m, 6H, 2-H, 3-H, 5-H2, and
CH2CH=), 3.69 (dd, 1H, J = 10.5, 4.2 Hz, one of CH2O), 3.95 (dd, 1H,
J = 10.5, 3.5 Hz, one of CH2O), 4.26–4.31 (m, 1H, 4-H), 4.94–5.09
1
(14) The spectroscopic properties (IR and H NMR) of these com-
pounds were identical with those of the corresponding racemic
samples.7