Synthesis and evaluation of A-ring diastereomers of 1α,25-dihydroxy-22-oxavitamin D3 (OCT)

Article abstract of DOI:10.1016/S0968-0896(00)00259-5

A-ring diastereomers of 1α,25-dihydroxy-22-oxavitamin D₃ (OCT) (2), 3-epi-1α,25-dihydroxy-22-oxavitamin D₃ (3-epiOCT) (3) and 1,3-diepi-1α,25-dihydroxy-22-oxavitamin D₃ (1,3-diepiOCT) (4) were synthesized by the convergent method. In vitro binding affinity for rat vitamin D binding protein and calf-thymus vitamin D receptor, differentiation-inducing activity on HL-60 cells, and transcriptional activity of 3-epiOCT (3) and 1,3-diepiOCT (4) were evaluated in comparison with OCT (2), 1-epi-1α,25-dihydroxy-22-oxavitamin D₃ (1-epiOCT) (5) and 1α,25-dihydroxyvitamin D₃ (1).

Full text of DOI:10.1016/S0968-0896(00)00259-5

Bioorganic & Medicinal Chemistry 9 (2001) 403±415
Synthesis and Evaluation of A-Ring Diastereomers of
1ꢀ,25-Dihydroxy-22-Oxavitamin D3 (OCT)1
Susumi Hatakeyama,a Toshio Okano,b Junji Maeyama,a Tomoyuki Esumi,a
Hiroko Hiyamizu,a Yoshiharu Iwabuchi,a Kimie Nakagawa,b
Keiichi Ozono,c Akira Kawased and Noboru Kuboderad,*
aFaculty of Pharmaceutical Sciences, Nagasaki University, Nagasaki 852±8521, Japan
bDepartment of Hygienic Sciences, Kobe Pharmaceutical University, Kobe 658±8558, Japan
cDepartment of Environmental Medicine, Osaka Medical Center for Material and Children Health, Osaka 594±1101, Japan
dChugai Pharmaceutical Co., Ltd., Tokyo 104±8301, Japan
Received 3 August 2000; accepted 23 September 2000
AbstractÐA-ring diastereomers of 1a,25-dihydroxy-22-oxavitamin D3 (OCT) (2), 3-epi-1a,25-dihydroxy-22-oxavitamin D3 (3-
epiOCT) (3) and 1,3-diepi-1a,25-dihydroxy-22-oxavitamin D3 (1,3-diepiOCT) (4) were synthesized by the convergent method. In
vitro binding anity for rat vitamin D binding protein and calf-thymus vitamin D receptor, di€erentiation-inducing activity on
HL-60 cells, and transcriptional activity of 3-epiOCT (3) and 1,3-diepiOCT (4) were evaluated in comparison with OCT (2), 1-epi-
1a,25-dihydroxy-22-oxavitamin D3 (1-epiOCT) (5) and 1a,25-dihydroxyvitamin D3 (1). # 2001 Elsevier Science Ltd. All rights
reserved.
Introduction
dihydroxyvitamin D3 (3-epi-1,25(OH)2D3) was isolated
in human keratinocytes9 or rat osteosarcoma cells10 incu-
bated with 1,25(OH)2D3. 3-Epi-1,25(OH)2D3 was also
found in the serum of rats treated with 1,25(OH)2D3.11 In
the case of 24,25-dihydroxyvitamin D3 (24,25(OH)2D3),
the other major natural metabolite of vitamin D3, 3-epi-
24,25-dihydroxyvitamin D3 was recently identi®ed in
the bile of rats administered with 24,25(OH)2D3.12
Although the biological characterization of the epimer-
ized vitamin D3 compounds at 3-position as yet remains
to be clari®ed, we have been interested in the new
metabolic pathway of vitamin D3 compounds at the A-
ring part in addition to the classic metabolic pathway at
the side chain. It is a matter of no little interest to us to
synthesize putative A-ring metabolites of OCT (2) and
investigate their biological characteristics. In this paper,
we describe the synthesis of 3-epi-1a,25-dihydroxy - 22 -
oxavitamin D3 (3-epiOCT) (3) and 1,3-diepi-1a,25-dihy-
droxy-22-oxavitamin D3 (1,3-diepiOCT) (4) as A-ring
diastereomers of OCT (2). Their in vitro binding anity
for calf-thymus vitamin D receptor (VDR) and rat
vitamin D binding protein (DBP), di€erentiation-indu-
cing activity on HL-60 cells, and transcriptional activity
using rat 24-hydroxylase gene and human osteocalcin gene
are also described as the preliminary biological evaluation
of synthesized A-ring diastereomers in comparison with
1,25(OH)2D3 (1), OCT (2), and 1-epi-1a,25-dihydroxy-
The active vitamin D3, 1a,25-dihydroxyvitamin D3 (1,25-
(OH)2D3) (1), is now well recognized as one of the
potent regulators of cell proliferation and di€erentiation
processes in addition to possessing a regulatory e€ect on
calcium and phosphorus metabolism.2 Various analogues
of 1,25(OH)2D3 (1) have been synthesized to separate
di€erentiation-induction and antiproliferation activities
from calcemic activity with the aim of obtaining useful
analogues for the medical treatment of psoriasis, cancer,
etc., without risk of hypercalcemia.3 1a,25-Dihydroxy-
22-oxavitamin D3 (OCT) (2) was obtained in such syn-
thetic studies and 2 has been shown to be highly potent
in stimulating monocytic di€erentiation of human pro-
myelocytic leukemic HL-60 cells but less calcemic than
1,25(OH)2D3 (1).4À6 OCT (2) is now under the process
of approval as an injection for the treatment of second-
ary hyperparathyroidism underlying renal insuciency7
and as an ointment for skin disease, psoriasis.8
Recently, the epimerization of the 3-hydroxy group of
vitamin D3 compounds has been reported. 3-Epi-1a,25-
*Corresponding author. Tel.: +81-3-3273-8558, fax: +81-3-3281-6675;
e-mail: kuboderanbr@chugai-pharm.co.jp
0968-0896/01/$ - see front matter # 2001 Elsevier Science Ltd. All rights reserved.
PII: S0968-0896(00)00259-5

404
S. Hatakeyama et al. / Bioorg. Med. Chem. 9 (2001) 403±415
22-oxavitamin D3 (1-epiOCT) (5), which was previously
prepared as 1b-hydroxylated OCT.13 OCT (2), 3-
epiOCT (3), 1,3-diepi OCT (4), and 1-epiOCT (5) con-
sist of all possible A-ring diastereomers of OCT (2)
(Fig. 1).
Synthesis of the A-ring fragment (35) of 1,3-diepiOCT (4)
For the synthesis of the A-ring fragment (35) of 1,3-
diepiOCT (4), we selected a more stereoselective route
than that employed in the above-mentioned synthesis of
the A-ring fragment (21) of 3-epiOCT (3), in order to
construct the C3 asymmetric center of 35 (the vitamin D
numbering) without formation of stereoisomers. Horner±
Emmons reaction between triethyl phosphonoacetate and
the aldehyde (12b), obtained from the allyl alcohol (6) in
the same manner as described for the preparation of the
enantiomer (12a), produced the ester (22) in 86% yield,
which was reduced with DIBAL to give the allyl alcohol
(23) in 87% yield. Katsuki±Sharpless epoxidation of 23
using diisopropyl d-tartrate (d-DIPT) was accomplished
quantitatively to a€ord the epoxide (24). Treatment of 24
with bis(2-methoxyethoxy)aluminum hydride (Red-Al)18
allowed regioselective reductive opening of the epoxy
ring to give the alcohol (25). Upon monopivaloylation,
silylation, and saponi®cation, 25 a€orded the anti-
diTBS ether (27) in 80% yield together with the corre-
sponding syn-diTBS ether (8%). The latter was derived
from the minor product of the Katsuki±Sharpless
epoxidation of 23 and was easily separated from 27 by
column chromatography at this stage. Swern oxidation of
27, condensation of the resulting aldehyde (28) with
methyl acetate, and subsequent Dess±Martin oxidation of
29 gave rise to the ketone (30). According to the method
developed by Takahashi and co-workers,19 the ketone
(30) was transformed into the alcohol (33) in 51%
overall yield by a three-step sequence involving tri¯a-
tion, DIBAL reduction, and intramolecular Heck reac-
tion. The A-ring fragment (35) for the synthesis of 1,3-
diepiOCT (4) was obtained from 33 by the same method
as described in the preparation of 21 from 18 (Fig. 3).
Results and Discussion
Synthesis of the A-ring fragment (21) of 3-epiOCT (3)
To synthesize 3-epiOCT (3) and 1,3-diepiOCT (4), we
adopted the convergent method, in which the A-ring
fragments (21 and 35) are coupled with the C/D-ring
fragment (37) for the construction of the triene system of
vitamin D3 structures. First, we undertook the synthesis
of the A-ring fragment (21) of 3-epiOCT (3). The epoxide
(8a), obtained by Katsuki±Sharpless epoxidation14 of the
allyl alcohol (6) using diisopropyl l-tartrate (l-DIPT)
and subsequent iodination of 7a, was subjected to
reductive cleavage using zinc in methanol containing ace-
tic acid to give the alcohol (9a) in 92% yield. After pro-
tection of the hydroxy group as its tert-butyldimethylsilyl
(TBS) ether, deprotection of the 4-methoxybenzyl (MPM)
group of 10a, followed by Swern oxidation of the
resulting alcohol (11a), gave the aldehyde (12a) in 63%
overall yield. The aldehyde (12a) was then reacted with
the dianion generated by the action of methyl aceto-
acetate and lithium diisopropylamide (LDA) to provide
the keto-ester (13) as a 1:1 epimeric mixture, which,
upon silylation, a€orded the TBS ether (14) and the TBS
enol ether (15) in 28% and 32% yields from 12a, respec-
tively. Treatment of 15 with silica gel in methanol resulted
in the formation of 14 in 67% yield. Tri¯ation of the
sodium enolate of 14 with 2-[N,N-bis(tri¯uoromethylsul-
fonyl)amino]pyridine (2-Py-N-Tf2)15 gave the Z-vinyl tri-
¯ate (16) in 70% yield, accompanied by the E-isomer (6%),
which was easily separated out by column chromato-
graphy. Upon treatment of 16 with a catalytic amount of
tetrakis(triphenylphosphine)palladium(0) ((Ph3P)4Pd)
(0.1 equiv) and silver oxide (Ag2O) (1 equiv) in boiling
tetrahydrofuran (THF), intramolecular Heck reaction16
took place cleanly to produce the cyclized ester (17) in
78% yield. Reduction of 17 with diisobutylaluminum
hydride (DIBAL) gave the alcohols (18 and 19) each in
40% yield, after separation by column chromatography.
The alcohol 18 is the precursor of the A-ring fragment
of 3-epiOCT (3), whereas 19 corresponds to that of
OCT (2). According to the established procedure,17 the
A-ring fragment (21) of 3-epiOCT (3) was ®nally
obtained from 18 via the chloride (20) (Fig. 2).
Preparation of the C/D-ring fragment (37)
The C/D-ring fragment (37) was prepared from OCT (2)
via 36 in 23% overall yield by a three-step sequence; i)
silylation with trimethylsilyl tri¯uoromethanesulfonate
(TMSOTf), ii) ozonolysis followed by sodium borohydride
reduction, and iii) oxidation using tetrapropylammonium
perruthenate (TPAP)20 and N-methylmorpholine N-oxide
(Fig. 4).
Coupling of the A-ring fragments (21 and 35) and C/D-
ring fragment (37)
Having obtained the A-ring fragments (21 and 35) and
the C/D-ring fragment (37), we performed the coupling
Figure 1. Structures of active vitamin D3 and OCT analogues.

S. Hatakeyama et al. / Bioorg. Med. Chem. 9 (2001) 403±415
405
Figure 2. Synthesis of the A-ring fragment (21) of 3-epiOCT (3). (b)-Series of 7±12 correspond to enantiomers of (a)-series for the synthesis of the
A-ring fragment (35) of 1,3-diepiOCT (4); (a) l-DIPT/tert-BuOOH/Ti(OiPr)4/CH2Cl2; (b) Ph3P/I2/THF±MeOH; (c) Zn/AcOH±MeOH; (d) TBSCl/
Et3N/DMAP/CH2Cl2; (e) DDQ/CH2Cl2±H2O; (f) (COCl)2/DMSO/Et3N/CH2Cl2; (g) MeCOCH2COOMe/LDA/THF; (h) TBSOTf/Et3N/CH2Cl2;
(i) SiO2/MeOH; (j) 2-Py-N-Tf2/NaH/THF; (k) Pd(tpp)4/Ag2O/THF; (l) DIBAL/CH2Cl2; (m) NCS/Me2S/CH2Cl2; (n) 1) HPPh2/n-BuLi/THF, 2)
H2O2/CHCl3±H2O.
Figure 3. Synthesis of the A-ring fragment (35) of 1,3-diepiOCT (4); (a) (EtO)2P(O)CH2COOEt/NaH/THF; (b) DIBAL/CH2Cl2; (c) d-DIPT/tert-
BuOOH/Ti(OiPr)4/CH2Cl2; (d) Red-Al/toluene; (e) PivCl/pyridine/CH2Cl2; (f) 1) TBSCl/2,6-lutidine/DMF, 2) 10 N NaOH/MeOH; (g) (COCl)2/
DMSO/Et3N/CH2Cl2; (h) MeCOOMe/n-Buli/diisopropylamine/THF; (i) Dess±Martin reagent/CH2Cl2; (j) 2-Py-N-Tf2/NaH/THF; (k) DIBAL/
CH2Cl2; (l) Ph3P/Et3N/Pd(OAc)2/DMF; (m) NCS/Me2S/CH2Cl2; (n) 1) HPPh2/n-BuLi/THF, 2) H2O2/CHCl3±H2O.
Biological evaluation
reaction17 in the presence of n-butyllithium (n-BuLi) to
give 38 and 39 in 45% and 33% yields, respectively.
Finally, deprotection of the silyl protecting groups of 38
and 39 with tetrabutylammonium ¯uoride (TBAF) furn-
ished 3-epiOCT (3) and 1,3-diepiOCT (4), respectively
(Fig. 5).
The preliminary biological characteristics of 3-epiOCT (3)
and 1,3-diepiOCT (4) were evaluated in comparison with
1,25(OH)2D3 (1), OCT (2) and 1-epiOCT (5). 1-EpiOCT
(5) was previously synthesized as 1b-hydroxylated OCT13
taking the relationship between 1,25(OH)2D3 (1) and

406
S. Hatakeyama et al. / Bioorg. Med. Chem. 9 (2001) 403±415
Figure 4. Preparation of the C/D-ring fragment (37). (a) 1) TMSOTf/Et3N/CH2Cl2, 2) O3/MeOH±CH2Cl2, 3) NaBH4/MeOH; (b) TPAP/NMO/CH2Cl2.
Figure 5. Synthesis of 3-epiOCT (3) and 1,3-diepiOCT (4). (a) n-BuLi/THF; (b) TBAF/THF.
1b-hydroxylated 1,25(OH)2D3, which seemed to be a
potent stereospeci®c antagonist of 1, into considera-
tion.21 The results of in vitro binding anity for rat
DBP and calf-thymus VDR, di€erentiation-inducing
activity on human promyelocytic leukemic HL-60 cells,
and transcriptional activities on rat 24-hydroxylase gene
and human osteocalcin gene in transfected human
osteosarcoma MG-63 cells are summarized in Table 1.
Among the A-ring diasteromers of OCT, 1,3-diepiOCT
(4) and 1-epiOCT (5) showed weak binding anity for
DBP, although OCT (2) and 3-epiOCT (3) did not
reveal anity in this experiment, compared to 1,25-
(OH)2D3 (1). b-Hydroxy con®guration at 1-position of
OCT diastereomers might be important to realize bind-
ing anity for DBP. As for binding anity for VDR,
OCT (2) showed 1/20 anity of 1,25(OH)2D3 (1), as
reported previously.6 1-EpiOCT (5) did not bind VDR,
as also reported before.13 The VDR binding anity of
both 3-epiOCT (3) and 1,3-diepiOCT (4) was approxi-
mated as 1/200 of OCT (2) and 1/4000 of 1,25(OH)2D3
(1). The combination between hydroxy substituents at
1- and 3-positions of A-ring diastereomers had a great
in¯uence on binding ability for VDR. In di€erentiation-
inducing e€ects and transcriptional activities, only OCT
(2) showed more potent e€ects than 1,25(OH)2D3 (1).
Slight ecacy was found in 3-epiOCT (3); however, it
was not found in both 1,3-diepiOCT (4) and 1-epiOCT
(5). This might be explained by the fact that a natural a-
hydroxy con®guration at 1-position of OCT diaster-
eomers plays an important role in the realization of
di€erentiation-inducing and transcriptional activities.
The detailed biological characteristics of A-ring diaster-
eomers of OCT and metabolic epimerization at A-ring
moiety incubated with OCT (2) will be discussed else-
where soon.
Experimental
General
Optical rotations were measured with Horiba SEPA-200
and JASCO DIP-140 polarimeters. Infrared (IR) spec-
tra were obtained using Horiba FT-730, JASCO ET/IR-
5300, JEOL JIR-6000, and Hitachi 270-30 spectro-
1
photometers. H and 13C NMR spectra were recorded
on VARIAN Gemini-300, JEOL FX-200, and JNM-
270EX spectrometers using CDCl3 as a solvent. Che-
mical shifts are reported in parts per million (ppm)
down®eld from tetramethylsilane or calibrated from
CHCl3. Mass spectra (MS) were measured with JEOL
JMS-HX-100, Shimadzu GCMS QP-5050A, and Hita-
chi M1200H instruments. High resolution mass spectra
(HRMS) were recorded on JEOL JMS-AX-500 and VG
Auto Spec Q instruments. Ultraviolet (UV) spectra were
obtained with a Shimadzu UV-240 spectrometer using
EtOH as a solvent. All reactions were carried out under
an atmosphere of argon unless otherwise noted. All
extracts were dried over MgSO4 and evaporated under
reduced pressure with a rotary evaporator. Chromato-
graphic puri®cation was carried out with Merck silica
gel 60 (column) or Merck silica gel 60 PF254 (peparative
TLC).
Table 1. Biological characteristics of 1,25(OH)2D3 (1), OCT (2) and
analogues 3±5
DBPa VDRb HL-60c Rat 24-
OHased osteocalcine
Human
1,25(OH)2D3 (1)
OCT (2)
3-EpiOCT (3)
1,3-DiepiOCT (4)
1-EpiOCT (5)
100
N.B
N.B.
7.2 <0.1
0.9 N.B.
100
5.1
<0.1
100
130
5
<1
<1
100
433
19
<1
<1
100
422
10
<1
<1.
aDBP: Anity for rat vitamin D binding protein (N.B.: no binding).
bVDR: Anity for calf-thymus vitamin D receptor (N.B.: no binding).
cHL-60: Di€erentiation-inducing e€ect on HL-60 cells.
dRat 24-OHase: Transcriptional activity on rat 24-hydroxylase gene.
eHuman osteocalcin: Transcriptional activity on human osteocalcin
gene.
(2S,3S)-2,3-Epoxy-5-(4-methoxybenzyl)oxy-1-pentanol
(7a). To a stirred solution of l-DIPT (474 mg, 2.03
mmol) and molecular sieves (4 A, 405 mg) in CH2Cl2
(12 mL) at À23 ꢀC was added Ti(OiPr)4 (468 mL, 1.58
mmol). The resulting mixture was stirred at À23 ꢀC for

S. Hatakeyama et al. / Bioorg. Med. Chem. 9 (2001) 403±415
407
10 min and a solution of 6 (5.00 g, 22.5 mmol) in CH2Cl2
(11 mL) and tert-BuOOH (2.97 M solution in CH2Cl2,
15 mL, 45.0 mmol) were added at À23 ꢀC. After being
stirred at À15 ꢀC for 2.5 d, the reaction mixture was
quenched by the addition of saturated Na2SO4 and Et2O.
The mixture was stirred at rt for 2 h, ®ltered through
Celite, evaporated, and chromatographed on silica gel.
Elution with AcOEt:hexane (2:3) gave 7a (4.92 g, 92%,
91% ee) as a colorless oil. IR (neat) 3426, 1512, 1462,
NaHCO3, saturated NaHSO3 and saturated NaCl, dried,
evaporated, and chromatographed on silica gel. Elution
with AcOEt:hexane (1:3) gave 8b (40.5 g, 99%) as a col-
1
orless oil. The results of IR, H NMR, 13C NMR, MS,
HRMS and optical rotation (opposite) were identical
with 8a.
(3S)-5-(4-Methoxybenzyl)oxy-1-penten-3-ol (9a). Amix-
ture of 8a (5.39 g, 15.5 mmol) and Zn (3.04 g, 46.5
mmol) in MeOH (200 mL) and AcOH (8 mL) was stir-
red under sonication at 37 ꢀC for 1 h. The mixture was
diluted with Et2O, ®ltered through Celite, washed with
5% HCl, saturated NaHCO3 and saturated NaCl, dried,
evaporated, and chromatographed on silica gel. Elution
with AcOEt:hexane (2:7) gave 9a (3.18 g, 92%) as a
colorless oil. IR (neat) 3427, 1612, 1513, 1249, 1095,
1
1248, 1176, 1097cmÀ1. H NMR d: 1.70±1.99 (3H, m),
2.97 (1H, d, t, J=2.7, 4.2 Hz), 3.10 (1H, d, d, d, J=2.7,
5.1, 6.6 Hz), 3.58 (2H, t, J=5.7Hz), 3.62 (1H, d, d, d,
J=4.2, 7.2, 12.3 Hz), 3.81 (3H, s), 3.90 (1H, d, d, d,
J=2.7, 5.7, 12.3 Hz), 4.45 (2H, s), 6.88 (2H, d, J=8.7Hz),
7.26 (2H, d, J=8.7 Hz). 13C NMR d: 32.0, 53.7, 55.2, 58.5,
61.8, 66.5, 72.7, 113.8, 129.2, 130.2, 159.1. MS (m/z) 238
(M+), 207, 137, 121, 83 (100%). HRMS calcd for
C13H18O4 238.1205, found 238.1222. [a]1d8 À27.7ꢀ (c
0.90, CHCl3).
1
1033 cmÀ1. H NMR d: 1.73±1.92 (2H, m), 2.98 (1H, d,
J=3.6 Hz), 3.56±3.73 (2H, m), 3.81 (3H, s), 4.28±4.38
(1H, m), 4.45 (2H, s), 5.10 (1H, d, t, J=1.2, 10.8 Hz),
5.27 (1H, d, t, J=1.2, 17.4 Hz), 5.87 (1H, d, d, d, J=5.4,
10.8, 17.4 Hz), 6.88 (2H, d, J=8.7 Hz), 7.25 (2H, d,
J=8.4 Hz). 13C NMR d: 36.1, 55.4, 68.1, 72.3, 73.1,
113.9, 114.7, 129.5, 129.8, 140.3, 159.3. MS (m/z) 222
(M+), 221, 121 (100%). HRMS calcd for C13H18O3
222.1256, found 222.1249. [a]2d0 +8.5ꢀ (c 0.98, CHCl3).
(2R,3R)-2,3-Epoxy-5-(4-methoxybenzyl)oxy-1-pentanol
(7b). To a stirred solution of d-DIPT (1.21 g, 5.15
mmol) and molecular sieves (4 A, 8 g) in CH2Cl2 (500
mL) at À25 ꢀC was added Ti(OiPr)4 (1.18 mL, 3.99
mmol). The resulting mixture was stirred at À25 ꢀC for
30 min and a solution of 6 (12.72 g, 57 mmol) in CH2Cl2
(50 mL) and tert-BuOOH (2.97 M solution in CH2Cl2,
38.4 mL, 114 mmol) at À25 ꢀC were added. After being
stirred at À15 ꢀC for 40.5 h, the reaction mixture was
quenched by the addition of saturated Na2SO4 and
Et2O. The mixture was stirred at rt for 2 h, ®ltered
through Celite, evaporated, and chromatographed on
silica gel. Elution with AcOEt:hexane (2:3) gave 7b
(12.44 g, 92%, 91% ee) as a colorless oil. The results of
IR, 1H NMR, 13C NMR, MS (m/z), HRMS and optical
rotation (opposite) were identical with 7a.
(3R)-5-(4-Methoxybenzyl)oxy-1-penten-3-ol (9b). Amix-
ture of 8b (13.9 g, 40 mmol) and Zn (7.85 g, 120 mmol)
in MeOH (400 mL) and AcOH (20.6 mL) was stirred
under sonication at 37 ꢀC for 2.5 h. The mixture was
diluted with AcOEt, ®ltered through Celite, washed
with 5% HCl, saturated NaHCO3 and saturated NaCl,
dried, evaporated, and chromatographed on silica gel.
Elution with AcOEt:hexane (2:7) gave 9b (8.79 g, 98%)
as a colorless oil. The results of IR, 1H NMR, 13C
NMR, MS, HRMS and optical rotation (opposite) were
identical with 9a.
(2R,3R)-2,3-Epoxy-1-iodo-5-(4-methoxybenzyl)oxypen-
tane (8a). Amixture of 7a (4.00 g, 16.8 mmol), imida-
zole (8.58 g, 126 mmol), Ph3P (13.2 g, 50.4 mmol), and I2
(12.8 g, 50.4 mmol) in THF (240 mL) and CH3CN (60
mL) was stirred at rt for 30 min. The mixture was dilu-
ted with Et2O, washed with saturated NaHCO3, satu-
rated NaHSO3 and saturated NaCl, dried, evaporated,
and chromatographed on silica gel. Elution with
AcOEt:hexane (1:20) gave 8a (5.88 g, 100%) as a pale
yellow oil. IR (neat) 1612, 1512, 1460, 1361, 1301, 1249,
(3S)-3-(tert-Butyldimethylsilyl)oxy-5-(4-methoxybenzyl)
oxy-1-pentene (10a). To a stirred solution of 9a (5.15 g,
35.9 mmol) in CH2Cl2 (100 mL) at 0 ꢀC were added Et3N
(5.0mL, 35.9 mmol), 4-(dimethylamino)pyridine (DMAP)
(169 mg, 1.38 mmol), and TBSCl (97%, 5.15 g, 33.1 mmol).
The resulting mixture was stirred at rt for 16 h, quenched
with saturated NaHCO3, extracted with AcOEt, dried,
evaporated, and chromatographed on silica gel. Elution
with AcOEt:hexane (1:10) gave 10a (4.33 g, 93%) as a
colorless oil. IR (neat) 1620, 1515, 1405, 1360, 1300, 1250,
1
1174, 1100, 1033 cmÀ1. H NMR d: 1.73±1.95 (2H, m),
1
2.98 (1H, d, d, d, J=1.8, 5.1, 6.3 Hz), 3.06 (1H, d, d, d,
J=1.8, 6.6, 8.7 Hz), 3.07 (1H, d, d, J=6.3, 12.6 Hz),
3.22 (1H, d, d, J=8.7, 12.6 Hz), 3.57 (2H, t, J=5.7 Hz),
3.81 (3H, s), 6.89 (2H, d, J=9.0 Hz), 7.27 (2H, d,
J=9.0 Hz). 13C NMR d: 5.0, 32.2, 55.3, 58.3, 60.3, 66.4,
72.8, 113.8, 129.3, 130.2, 159.2. MS (m/z) 348 (M+), 221,
121 (100%). HRMS calcd for C13H17O3I 348.0222,
found 348.0216. [a]1d9 +4.3ꢀ (c 1.04, CHCl3).
1090, 1040cmÀ1. H NMR d: 0.03 (3H, s), 0.05 (3H, s),
0.89 (9H, s), 1.77 (2H, q, J=7.7 Hz), 3.43±3.60 (2H, m),
3.81 (3H, s), 4.28 (1H, q, J=6.6Hz), 4.38 (1H, d, J=
11.0Hz), 4.45 (1H, d, J=11.0 Hz), 5.01 (1H, d, t, J=2.0,
10.0Hz), 5.14 (1H, d, t, J=2.0, 17.0 Hz), 5.80 (1H, d, d, d,
J=6.6, 10.0, 17.0 Hz), 6.88 (2H, d, J=8.7 Hz), 7.26 (2H,
d, J=8.7 Hz). 13C NMR d: À4.8, À4.3, 18.3, 38.2, 55.4,
66.5, 70.9, 72.7, 113.7, 113.8, 129.4, 130.7, 141.7, 159.2.
MS (m/z) 336 (M+), 279, 122 (100%). HRMS calcd for
C19H32O3Si 336.2121, found 336.2066. [a]1d8 +2.0ꢀ (c
0.99, CHCl3).
(2S,3S)-2,3-Epoxy-1-iodo-5-(4-methoxybenzyl)oxypen-
tane (8b). Amixture of 7b (27.9 g, 117 mmol), imida-
zole (59.8 g, 878 mmol), Ph3P (92.2 g, 352 mmol), and I2
(89.3 g, 352 mmol) in THF (680 mL) and CH3CN (170
mL) was stirred under ice cooling for 30 min. The mix-
ture was diluted with hexane, washed with saturated
(3R)-3-(tert-Butyldimethylsilyl)oxy-5-(4-methoxybenzyl)
oxy-1-pentene (10b). To a stirred solution of 9b (10.9 g,
49 mmol) in CH2Cl2 (250 mL) at 0 ꢀC were added Et3N

408
S. Hatakeyama et al. / Bioorg. Med. Chem. 9 (2001) 403±415
(20.4 mL, 147 mmol), DMAP (600 mg, 5 mmol), and
TBSCl (97%, 22.1 g, 147 mmol). The resulting mixture
was stirred at rt for 21 h, quenched with saturated
AcOEt, washed with 0.5 N HCl, saturated NaHCO3,
and saturated NaCl, dried, evaporated, and chromato-
graphed on silica gel. Elution with AcOEt:hexane (1:30)
gave 10b (16.5 g, 100%) as a colorless oil. The results of
IR, 1H NMR, 13C NMR, MS, HRMS and optical
rotation (opposite) were identical with 10a.
J=2.7, 6.6, 15.6 Hz), 4.65 (1H, br q, J=5.1 Hz), 5.13
(1H, d, t, J=1.5, 10.5 Hz), 5.27 (1H, d, t, J=1.5,
17.1 Hz), 5.88 (1H, d, d, d, J=5.7, 10.5, 17.1 Hz), 9.79
(1H, br t, J=2.5 Hz). MS (m/z) 185 (M+ÀCHO), 171,
157, 75 (100%).
(3R)-3-(tert-Butyldimethylsilyl)oxy-4-pentenal (12b). To
a stirred solution of (COCl)2 (7.2 mL, 82 mmol) in
CH2Cl2 (150 mL) at À63 ꢀC was added DMSO (11.6
mL, 164 mmol) in CH2Cl2 (50 mL). The resulting mix-
ture was stirred at the same temperature for 15 min. To
the mixture was added 11b (8.0 g, 41 mmol) in CH2Cl2
(50 mL) at À63 ꢀC. The resulting mixture was stirred at
the same temperature for 40 min. After addition of Et3N
(46 mL, 328 mmol) at À63 ꢀC, the resulting mixture was
allowed to warm to rt and the stirring was continued at
room temperature for 1 h. To the mixture was added
0.1 M HCl. The mixture was extracted with Et2O,
washed with saturated NaCl, dried, and evaporated to
give practically pure 12b (7.8 g, 97%) as a pale yellow
oil, which was used without further puri®cation. The
(3S)-3-(tert-Butyldimethylsilyl)oxy-4-penten-1-ol (11a).
To a stirred mixture of 10a (531 mg, 1.58 mmol) in 5%
aqueous CH2Cl2 (5 mL) was added 2,3-dichloro-5,6-
dicyano-1,4-benzoquinone (DDQ) (539 mg, 2.38 mmol)
at rt. The resulting mixture was stirred for 15 min and
saturated NaHCO3 (5 mL) was added. The mixture was
extracted with CH2Cl2, washed with saturated NaHCO3,
dried, evaporated, and chromatographed on silica gel.
Elution with AcOEt:hexane (1:10) gave 11a (377 mg,
100%) as a pale yellow oil. IR (neat) 3350, 1467, 1405,
1
1362, 1254, 1087, 1024 cmÀ1. H NMR d: 0.06 (3H, s),
1
0.10 (3H, s), 0.91 (9H, s), 1.65±1.78 (1H, m), 1.79±1.91
(1H, m), 2.46 (1H, br t, J=5.4 Hz), 3.66±3.76 (1H, m),
3.78±3.88 (1H, m), 4.42 (1H, br q, J=6.0 Hz), 5.11 (1H,
d, t, J=1.8, 9.3 Hz), 5.23 (1H, d, t, J=1.8, 17.4 Hz), 5.85
(1H, d, d, d, J=5.7, 9.3, 17.4 Hz). 13C NMR d: À5.0,
À4.3, 18.2, 25.9, 39.2, 60.2, 73.3, 114.5, 140.7. MS (m/z)
216 (M+), 171, 160, 159, 75 (100%). HRMS calcd for
C9H19OSi 171.1205, found 171.1204. [a]2d0 +3.3ꢀ (c
0.94, CHCl3).
results of H NMR and MS were identical with 12a.
Methyl (5RS,7S)-5,7-bis(tert-butyldimethylsilyl)oxy-3-
oxo-8-nonenoate (14). To a stirred mixture of LDA
(0.7 M solution in THF, 41.6 mL, 29.1 mmol) at À78 ꢀC
was added methyl acetoacetate (1.4 mL, 13.0 mmol).
The resulting mixture was stirred at 0 ꢀC for 1.5 h and a
solution of 12a (1.18 g, 5.22 mmol) in THF (2 mL) was
added at 0 ꢀC. After being stirred at the same temperature
for 40 min, the reaction mixture was quenched with satu-
rated NH4Cl, extracted with AcOEt, washed with satu-
rated NH4Cl, dried, and evaporated to give 13 (1.70 g) as a
yellow oil, which was used for the next reaction without
puri®cation. Asample for 1H NMR spectrum was
obtained by preparative TLC developed with AcOEt:hex-
(3R)-3-(tert-Butyldimethylsilyl)oxy-4-penten-1-ol (11b).
To a stirred mixture of 10b (16.1 g, 48 mmol) in 5%
aqueous CH2Cl2 (200 mL) was added DDQ (12.0 g,
53 mmol) under ice cooling. The resulting mixture was
stirred for 1 h at the same temperature and ®ltered
through Celite. The ®ltrate was washed with saturated
NaHCO3 and saturated NaCl, dried, and evaporated.
The residue was dissolved in MeOH (150 mL) and trea-
ted with NaBH4 (0.875 g, 23 mmol). The resulting mix-
ture was stirred at room temperature for 30 min and
extracted with Et2O. The extract was washed with
saturated NH4Cl and saturated NaCl, dried, evaporated,
and chromatographed on silica gel. Elution with AcOEt:
hexane (1:10) gave 11b (8.3 g, 81%) as a colorless oil. The
1
ane (2:5). H NMR d: 0.06 (3H, s), 0.10 (3H, s), 0.90
(4.5H, s), 0.91 (4.5H, s), 1.52±1.79 (2H, m), 2.58±2.78
(2H, m), 3.51 (1H, s), 3.52 (1H, s), 3.74 (3H, s), 4.20±
4.28 (0.5H, m), 4.38 (1H, m), 4.46±4.56 (0.5H, m), 5.08
(0.5H, br d, J=10.5 Hz), 5.12 (0.5H, br d, J=12.0 Hz),
5.18 (0.5H, br d, J=17.1 Hz), 5.25 (0.5H, br d,
J=17.1 Hz), 5.74±5.92 (1H, m). To a stirred solution of
crude 13 (1.70 g, 5.15 mmol) in CH2Cl2 (50 mL) at
À78 ꢀC were added Et3N (1.08 mL, 7.74 mmol) and tert-
butyldimethylsilyl tri¯uoromethanesulfonate (TBSOTf,
1.42 mL, 6.18 mmol). After being stirred at À78 ꢀC for
20 min, the reaction mixture was quenched with satu-
rated NaHCO3 (20 mL), extracted with AcOEt, washed
with saturated NH4Cl and saturated NaCl, dried, eva-
porated, and chromatographed on silica gel. Elution
with AcOEt:hexane (1:15) gave 14 (649 mg, 28% from
12a) as a colorless oil and the silyl enolate (15) (962 mg,
32%) as a colorless oil. Compound 15 was converted to
14 as follows. Amixture of 15 (586 mg, 1.05 mmol) and
silica gel (5.90 g) in MeOH (58 mL) was stirred at room
temperature for 5 days. The mixture was diluted with
AcOEt, ®ltered through silica gel, evaporated, and chro-
matographed on silica gel. Elution with AcOEt:hexane
(1:30) gave 14 (314 mg, 67%) as a colorless oil. 1H
NMR d: 0.00±0.10 (12H, m), 0.86 (4.5H, s), 0.87 (4.5H,
s), 0.88 (4.5H, s), 0.89 (4.5H, s), 1.57±1.82 (2H, m),
2.24±2.47 (0.5H, m), 2.69±2.74 (1.5H, m), 3.47 (0.75H,
1
results of IR, H NMR, 13C NMR, MS, HRMS and
optical rotation (opposite) were identical with 11a.
(3S)-3-(tert-Butyldimethylsilyl)oxy-4-pentenal (12a). To
a stirred solution of (COCl)2 (0.9 mL, 10.3 mmol) in
CH2Cl2 (40 mL) at À63 ꢀC was added DMSO (1.46 mL,
20.6 mmol). The resulting mixture was stirred at the same
temperature for 30 min. To the mixture was added 11a
(1.11 g, 5.16 mmol) in CH2Cl2 (5 mL) at À63 ꢀC. The
resulting mixture was stirred at the same temperature for
30 min. After addition of Et3N (5.8 mL, 41.3 mmol) at
À63 ꢀC, the resulting mixture was allowed to warm to
rt. 0.1 M HCl was added and the mixture was extracted
with AcOEt, washed with saturated NaCl, dried, and
evaporated to give crude 12a (1.08 g, 97%) as a pale
yellow oil, which was used without further puri®cation.
1H NMR d: 0.06 (3H, s), 0.07 (3H, s), 0.88 (9H, s), 2.50
(1H, d, d, d, J=2.1, 4.8, 15.6 Hz), 2.62 (1H, d, d, d,

S. Hatakeyama et al. / Bioorg. Med. Chem. 9 (2001) 403±415
409
s), 3.48 (0.75H, s), 4.07±4.35 (2H, m), 5.02 (0.25H, s),
5.05 (1H, br d, J=10.2 Hz), 5.14 (0.5H, br d,
J=17.4 Hz), 5.16 (0.5H, br d, J=15.9 Hz), 5.72±5.87
(1H, m).
(1H, d, d, J=4.2, 8.7 Hz), 4.98 (1H, t, J=1.0 Hz), 5.18
(1H, t, J=1.0 Hz), 5.63 (1H, br s). MS (m/z) 426 (M+),
411, 369 (100%).
(Z,3S,5S)-2-[3,5-Bis(tert-butyldimethylsilyl)oxy-2-methyl-
enecyclohexylidene]ethanol (18) and (Z,3S,5R)-2-[3,5-
bis(tert - butyldimethylsilyl)oxy - 2 - methylenecyclohexyli-
dene] ethanol (19). To a stirred solution of DIBAL
(1.0 M solution in toluene, 1.3 mL, 1.3 mmol) at À78 ꢀC
was added a solution of 17 (206 mg, 0.483 mmol) in
CH2Cl2 (4.4 mL) dropwise. The resulting mixture was
stirred at À78 ꢀC for 30 min, quenched with 10% NaOH
at À78 ꢀC, and ®ltered through Celite. The ®ltrate was
diluted with CH2Cl2, washed with 10% citric acid, dried,
evaporated, and chromatographed on silica gel. Elution
with CH2Cl2 gave 18 (77 mg, 40%) as a colorless oil and
19 (77 mg, 40%) as a colorless solid.
Methyl (2Z,5RS,7S)-5,7-bis(tert-butyldimethylsilyl)oxy-
3 - (tri¯uoromethanesulfonyl)oxy - 2,8 - nonadienoate (16)
and methyl (2E,5RS,7S)-5,7-bis(tert-butyldimethylsilyl)
oxy-3-(tri¯uoromethanesulfonyl)oxy2,8-nonadienoate (E-
isomer). Amixture of 14 (393 mg, 0.885 mmol) and
NaH (60%, 41 mg, 1.03 mmol) in THF (4.7 mL) was
stirred at À5 ꢀC for 1 h. To the stirred mixture was
added 2-Py-N-Tf2 (333 mg, 1.05 mmol) and the mixture
was stirred at rt for 19.5 h. The reaction mixture was
quenched at 0 ꢀC with H2O (1 mL), diluted with Et2O
(80 mL), washed with H2O, 10% citric acid, 10% NaOH
and saturated NaCl, dried, evaporated, and chromato-
graphed on silica gel. Elution with AcOEt:hexane (1:50)
gave 16 (321 mg, 63%) as a colorless oil, E-isomer
(28 mg, 6%) as a colorless oil and the recovered 14
(72 mg, 18%).
18. IR (neat) 3353, 1512, 1467, 1254, 1080 cmÀ1 1H
.
NMR d: 0.06 (6H, s), 0.07 (3H, s), 0.08 (3H, s), 0.89 (9H,
s), 0.93 (9H, s), 1.56 (1H, q, J=11.7 Hz), 2.15±2.21 (2H,
m), 2.42 (1H, d, d, d, J=2.4, 5.1, 12.9 Hz), 3.73 (1H, t, t,
J=2.1, 11.1 Hz), 4.14 (1H, br d, J=12.6 Hz), 4.28 (1H,
d, d, J=8.4, 12.6 Hz), 4.76 (1H, t, J=2.4 Hz), 5.33 (1H, t,
J=2.4Hz), 5.55 (1H, d, d, d, J=1.8, 5.1, 7.5 Hz). 13C
NMR d: À4.9, À4.6, 18.2, 18.5, 25.9, 46.4, 46.5, 60.0, 68.3,
70.1, 109.9, 126.9, 138.4, 147.4. MS (m/z) 398 (M+), 380,
341, 73 (100%). HRMS calcd for C21H42O3Si2 398.2672,
found 398.2647.
1
16. H NMR d: 0.01±0.07 (12H, m), 0.86 (9H, s), 0.89
(9H, s), 1.62±1.88 (2H, m), 2.47 (0.5H, d, d, J=8.1,
15.3 Hz), 2.53 (0.5H, d, d, J=5.3, 15.3 Hz), 2.63 (0.5H, d,
d, J=5.1, 15.3 Hz), 2.75 (0.5H, d, d, J=4.2, 15.3 Hz), 3.75
(0.5H, s), 3.76 (0.5H, s), 4.06 (1H, m J=3.3Hz), 4.15
(0.5H, q, J=6.3 Hz), 4.27 (0.5H, q, J=4.8Hz), 5.09 (1H,
br d, J=10.5 Hz), 5.14 (0.5H, br d, J=16.8 Hz), 5.17
(0.5H, br d, J=16.8 Hz), 5.70±5.84 (1H, m), 5.81 (1H, s).
(Z,3S,5S)-2-[3,5-Bis(tert-butyldimethylsilyl)oxy-2-methyl-
enecyclohexylidene]-1-chloroethane (20). Amixture of N-
chlorosuccinimide (NCS, 181 mg, 1.36 mmol) and
dimethyl sul®de (DMS, 100 mL, 1.36 mmol) in CH2Cl2
(4.4 mL) was stirred at 0 ꢀC for 40 min. This solution
(1.2 mL) was then added dropwise to a stirred solution
of 18 (74 mg, 0.186 mmol) in CH2Cl2 (0.6 mL) at
À20 ꢀC. After being stirred at À20 ꢀC for 45 min and at
rt for 30 min, the reaction mixture was diluted with
hexane, washed with H2O and saturated NaCl, dried,
and evaporated to give 20 (70.6 mg, 91%) as a pale yel-
low oil, which was used without further puri®cation. IR
(neat) 1467, 1377, 1255, 1078cmÀ1. 1H NMR d: 0.07 (6H,
s), 0.08 (3H, s), 0.09 (3H, s), 0.89 (9H, s), 0.93 (9H, s), 1.56
(1H, q, J=11.4 Hz), 2.18 (2H, m), 2.43 (1H, d, d, d,
J=2.1, 4.8, 12.9 Hz), 3.71 (1H, t, t, J=4.5, 11.1 Hz),
3.94 (1H, d, d,t, J=2.1, 4.5, 11.7 Hz), 4.10 (1H, d, d,
J=1.5, 11.1 Hz), 4.18 (1H, d, d, J=8.1, 11.1 Hz), 4.96
(1H, t, J=2.1 Hz), 5.39 (1H, t, J= 2.1 Hz), 5.57 (1H, d,
t, J=2.1, 8.1 Hz). 13C NMR d: À4.8, À4.6, 18.2, 18.5,
25.9, 41.5, 46.4, 46.5, 68.1, 70.0, 110.1, 123.2, 141.1,
146.9. MS (m/z) 416 (M+), 401, 381, 73 (100%), 57.
HRMS calcd for C20H38O2Si2 (M+ÀCH3) 401.2099,
found 401.2065.
1
E-Isomer. H NMR d: 0.01±0.07 (12H, m), 0.85 (9H, s),
0.87 (4.5H, s), 0.89 (4.5H, s), 1.62±1.89 (2H, m), 2.96
(0.5H, d, d, J=5.4, 14.4 Hz), 3.09 (0.5H, d, d, J=5.4,
14.4 Hz), 3.26 (0.5H, d, d, J=6.0, 14.4 Hz), 3.28 (0.5H,
d, d, J=6.0, 14.4 Hz), 3.74 (1.5H, s), 3.75 (1.5H, s), 5.07
(1H, br d, J=10.2 Hz), 5.78 (1H, d, d, d, J=5.4, 10.2,
16.8 Hz), 5.98 (0.5H, s), 5.99 (0.5H, s).
Methyl (Z,3S,5RS)-[3,5-bis(tert-butyldimethylsilyl)oxy-
2-methylenecyclohexylidene]acetate (17). Amixture of
16 (356 mg, 0.617 mmol), Ag2O (158 mg, 0.676 mmol),
and Pd(tpp)4 (72 mg, 0.063 mmol) in THF (35 mL) was
stirred at 60 ꢀC for 24 h. The mixture was ®ltered
through silica gel, evaporated, and chromatographed on
silica gel. Elution with AcOEt:hexane (1:50) gave 17
(207 mg, 78%) as a colorless oil, which was used with-
out further puri®cation. The analytically pure sample
was obtained by preparative TLC.
5R-17. IR (neat) 1729, 1643, 1255, 1079 cmÀ1. 1H NMR
d: 0.06 (6H, s), 0.09 (3H, s), 0.10 (3H, s), 0.87 (9H, s),
0.94 (9H, s), 1.57 (1H, q, J=11.7 Hz), 2.15±2.27 (2H,
m), 2.38±2.50 (1H, m), 3.63 (3H, s), 3.64±3.80 (1H, m),
4.06±4.12 (1H, m), 4.96 (1H, t, J=2.1 Hz), 5.25 (1H, t,
J=2.1 Hz), 5.67 (1H, d, J=2.1 Hz). MS (m/z) 426
(M+), 411, 369 (100%).
(Z,3S,5S)-2-[3,5-Bis(tert-butyldimethylsilyl)oxy-2-methyl-
enecyclohexylidene]ethyl]diphenylphosphine oxide (21). To
a stirred solution of HPPh2 (136 mg, 0.728 mmol) in
THF (2.4 mL) at 0 ꢀC was added n-BuLi (1.58 M solu-
tion in hexane, 460 mL, 0.727 mmol) and the stirring was
continued for 10 min. The mixture was cooled to À50 ꢀC
and a solution of 20 (67.5 mg, 0.162 mmol) in THF
(1 mL) was added. The resulting mixture was stirred at
5S-17. IR (neat) 1722, 1641, 1253, 1077 cmÀ1. 1H NMR
d: 0.05 (6H, s), 0.09 (6H, s), 0.89 (9H, s), 0.90 (9H, s),
1.76 (1H, d, d, d, J=3.0, 9.0, 12.1 Hz), 1.93 (1H, d, t,
J=5.1, 12.1 Hz), 2.26 (1H, d, d, J=5.6, 13.1 Hz), 2.34
(1H, br d, J=13.1 Hz), 3.63 (3H, s), 4.24 (1H, m), 4.53

410
S. Hatakeyama et al. / Bioorg. Med. Chem. 9 (2001) 403±415
À50 ꢀC for 10 min, and quenched with H2O. CHCl3
(15 mL) and 5% H2O2 (5.4 mL) were added at rt and the
mixture was stirred for 1.5 h. The reaction mixture was
diluted with CHCl3, washed with saturated NaHCO3 and
H2O, dried, evaporated, and chromatographed on silica
gel. Elution with AcOEt:hexane (1:2) gave 21 (68.0 mg,
72%) as a colorless oil. IR (neat) 1437, 1253, 1120,
(645mg, 3 mmol) and molecular sieves (4 A, 1 g) in
CH2Cl2 (150mL) at À30ꢀC was added Ti(OiPr)4 (632mL,
2 mmol) and the resulting mixture was stirred at À30ꢀC
for 30min. Asolution of 23 (7.4g, 31mmol) in CH2Cl2
(25 mL) and tert-BuOOH (2.97 M solution in CH2Cl2,
20.5mL, 61mmol) were added at À30ꢀC and the mixture
was stirred at À15ꢀC for 30h. To the stirred mixture were
added saturated Na2SO4 and Et2O. The resulting mixture
was stirred at rt for 2 h, ®ltered through Celite, evapo-
rated, and chromatographed on silica gel. Elution with
AcOEt:hexane (1:4) gave 24 (8.0 g, 100%) as a colorless
1
1073cmÀ1. H NMR d: 0.03 (6H, s), 0.04 (3H, s), 0.05
(3H, s), 0.86 (9H, s), 0.92 (9H, s), 1.45 (1H, q, J=11.5 Hz),
2.05±2.15 (2H, m), 2.37 (1H, d, d, d, J=2.0, 4.5, 12.0 Hz),
3.15 (1H, d, d, d, d, J=2.5, 5.5, 15.0, 18.0 Hz), 3.32 (1H,
br d, t, J=10.0, 15.0 Hz), 3.40 (1H, t, t, J=4.0, 11.5 Hz),
3.53 (1H, d, d, t, J=2.0, 5.0, 9.0 Hz), 4.76 (1H, t,
J=2.5 Hz), 5.28 (1H, t, J=2.5 Hz), 5.49 (1H, d, d, t,
J=2.0, 5.0, 7.5 Hz), 7.42±7.76 (6H, m). 13C NMR d:
À4.8, À4.7, À4.6, À4.5, 25.8, 25.9, 31.1, 32.2, 46.6, 46.8,
68.3, 69.2, 109.7, 115.7. MS (m/z) 582 (M+), 525
(100%). HRMS calcd for C33H51O3PSi2 582.3115,
found 582.3088. [a]2d2 À38.0ꢀ (c 1.02, CHCl3).
1
oil. IR (neat) 3434, 1468, 1254, 1077 cmÀ1. H NMR d:
À0.05 (3H, s), À0.02 (3H, s), 1.50±1.70 (2H, m), 2.84
(1H, d, t, J=2.1, 4.5 Hz), 3.82 (1H, d, d, d, J=2.7, 6.0,
12.6 Hz), 4.96 (1H, d, t, J=1.5, 10.5 Hz), 5.11 (1H, d, t,
J=1.5, 17.1 Hz), 5.73 (1H, d, d, d, J=5.7, 10.5, 17.4 Hz).
13C NMR d: À4.9, À4.4, 18.2, 25.7, 40.5, 59.2, 61.8, 71.3,
114.1, 127.0, 141.1. MS (m/z) 201 (M+ÀC4H9), 146
(100%). HRMS calcd for C9H17O3Si (M+ÀC4H9)
201.0945, found 201.0957. [a]2d5 +15.4ꢀ (c 1.00, CHCl3).
Ethyl (5R)-5-(tert-butyldimethylsilyl)oxy-2,6-heptadieno-
ate (22). To a stirred mixture of NaH (60%, 3.26g,
82mmol) in THF (185mL) at 0 ꢀC was added dropwise
(EtO)2P(O)CH2COOEt (13.5 mL, 68mmol) and the
resulting mixture was stirred at rt for 1 h. To the cooled
(À78ꢀC) mixture was added 12b (7.8 g) in THF (50 mL)
dropwise. The resulting mixture was stirred at À78ꢀC for
30min, quenched with saturated NH4Cl at À78 ꢀC,
extracted with AcOEt, dried, evaporated, and chroma-
tographed on silica gel. Elution with AcOEt:hexane
(1:4) gave 22 (10.1 g, 86% from 11b) as a colorless oil. IR
(3S,5R)-5-(tert-Butyldimethylsilyl)oxy-6-hepten-1,3-diol
(25). To a stirred solution of 24 (1.4 g, 5.42 mmol) in
toluene (28 mL) at À30 ꢀC was added dropwise Red-Al
(65% solution in toluene, 3.25 mL, 10.83 mmol). The
resulting mixture was stirred at À30 ꢀC for 21 h, quen-
ched with saturated Na2SO4, ®ltered through Celite,
evaporated, and chromatographed on silica gel. Elution
with AcOEt:hexane (1:4) gave 25 (0.99 g, 70%) as a
1
colorless oil. IR (neat) 3365, 1467, 1254, 1072 cmÀ1. H
NMR d: 0.07 (3H, s), 0.10 (3H, s), 0.91 (9H, s), 1.52±
1.78 (3H, m), 1.85 (1H, d, d, J=4.5, 10.8 Hz), 2.85 (1H,
t, J=5.0 Hz), 3.82 (1H, d, t, J=5.1, 6.0 Hz), 3.93 (1H,
s), 4.19 (1H, m), 4.57 (1H, m), 5.10 (1H, d, t, J=1.5,
10.5 Hz), 5.26 (1H, d, t, J=1.5, 17.4 Hz), 5.87 (1H, d, d,
d, J=4.8, 10.5, 17.1 Hz). 13C NMR d: À4.6, À3.7, 25.9,
38.8, 44.4, 61.5, 71.4, 75.2, 114.8, 14.1.3. MS (m/z) 229
[M+À(H+2CH3)], 81 (100%). HRMS calcd for
C13H29O3Si (M++1) 261.1886, found 261.1933. [a]2d5
+1.7ꢀ (c 1.03, CHCl3).
1
(neat) 1722, 1259, 1083cmÀ1. H NMR d: 0.02 (3H, s),
0.04 (3H, s), 0.88 (9H, s), 1.27 (3H, t, J=7.2 Hz), 2.38 (2H,
t, J=7.5Hz), 4.17 (2H, q, J=7.2 Hz), 4.21 (1H, m), 5.07
(1H, d, J=10.5 Hz), 5.19 (1H, d, J=12.9 Hz), 5.80 (1H, d,
d, d, J=6.0, 10.5, 16.5 Hz), 5.83 (1H, d, J=16.2 Hz), 6.34
(0.003H, d, t, J=7.2, 14.4 Hz), 6.92 (0.997H, d, t,
J=7.5, 15.0 Hz). 13C NMR d: À4.9, À4.4, 14.3, 18.3,
25.9, 41.2, 60.2, 72.7, 114.6, 123.6, 140.6, 145.4. MS
(m/z) 269 (M+ÀCH3), 227 (100%). HRMS calcd for
C14H25O3Si (M+ÀCH3) 269.1573, found 269.1558. [a]2d0
À6.3ꢀ (c 0.82, CHCl3).
(3S,5R)-5-(tert-Butyldimethylsilyl)oxy-1-pivaloyloxy-6-
hepten-3-ol (26). To a stirred solution of 25 (2.7 g,
10.2 mmol) and pyridine (2.1 mL, 10.2 mmol) in CH2Cl2
(130 mL) at 0 ꢀC was added pivaloyl chloride (PivCl,
1.9 mL, 15.3 mmol). The resulting mixture was stirred at
rt for 3.5 h, quenched with H2O, extracted with CH2Cl2,
dried, evaporated, and chromatographed on silica gel.
Elution with AcOEt:hexane (1:20) gave 26 (3.3 g, 95%)
as a colorless oil. IR (neat) 1722, 1471, 1288, 1254, 1163,
(5R)-5-(tert-Butyldimethylsilyl)oxy-2,6-heptadien-1-ol (23).
To a stirred solution of 22 (10.1 g, 35 mmol) in CH2Cl2
(296 mL) at À78 ꢀC was added dropwise DIBAL (1 M
solution in toluene, 96 mL, 96 mmol). The resulting
mixture was stirred at À78 ꢀC for 1 h, quenched with
10% NaOH (4.6 mL), ®ltered through Celite, evapo-
rated, and chromatographed on silica gel. Elution with
AcOEt:hexane (1:10) gave 23 (7.4 g, 87%) as a colorless
1
1080 cmÀ1. H NMR d: 0.06 (3H, s), 0.09 (3H, s), 0.90
1
oil. IR (neat) 3352, 1253, 1082, 1031 cmÀ1. H NMR d:
(9H, s), 1.18 (9H, s), 1.59 (1H, d, d, d, J=2.1, 5.1,
14.1 Hz), 1.67±1.77 (3H, m), 3.94±4.02 (1H, m), 5.12
(1H, d, t, J=1.5, 10.8 Hz), 5.24 (1H, d, t, J=1.5,
17.4 Hz), 5.84 (1H, d, d, d, J=5.4, 10.8, 17.4 Hz). 13C
NMR d: À5.1, À4.5, 18.2 25.9, 27.3, 36.8, 38.8, 43.3,
61.3, 65.1, 72.4, 114.6, 140.2, 178.9. MS (m/z) 287
(M+ÀC4H9), 171, 131, 93 (100%). HRMS calcd for
C14H28O4Si (M+ÀC4H9) 287.1678, found 287.1693.
[a]2d4 À12.8ꢀ (c 0.98, CHCl3).
0.03 (3H, s), 0.04 (3H, s), 0.89 (9H, s), 2.21±2.28 (2H,
m), 4.10 (2H, br s), 4.15 (1H, t, J=6.0 Hz), 5.04 (1H, d,
t, J=5.7, 10.5 Hz), 5.16 (1H, d, t, J=1.8, 17.1 Hz), 5.64
(2H, m), 5.81 (1H, d, d, d, J=5.7, 10.5, 17.4 Hz). 13C
NMR d: À4.3, 16.6, 25.0, 41.2, 63.9, 73.5, 114.0, 129.2,
131.6, 141.1. MS (m/z) 241 (M+ÀC4H9), 171 (100%).
HRMS calcd for C9H17O2Si (M+) 185.0998, found
185.1000. [a]2d4 À10.8ꢀ (c 1.01, CHCl3).
(2R,3R,5R)-5-(tert-Butyldimethylsilyl)oxy-2,3-epoxy-6-
hepten-1-ol (24). To a stirred solution of d-DIPT
(3S,5R)-3,5-Bis(tert-butyldimethylsilyl)oxy-6-hepten-1-ol
(27). To a stirred solution of 26 (668 mg, 1.94 mmol) in

S. Hatakeyama et al. / Bioorg. Med. Chem. 9 (2001) 403±415
411
CH2Cl2 (6 mL) at 0 ꢀC were added 2,6-lutidine (0.29 mL,
2.52 mmol) and TBSOTf (0.53 mL, 2.32 mmol). The
resulting mixture was stirred at 0 ꢀC for 30 min, quen-
ched with MeOH, evaporated, and chromatographed
on silica gel. Elution with AcOEt:hexane (1:20) gave the
TBS ether of 26 as a colorless oil (860 mg, 97%). IR
1645, 1431, 1169, 1088 cmÀ1. H NMR d: 0.00 (3H, s),
0.03 (3H, s), 0.05 (3H, s), 0.06 (3H, s), 0.85 (18H, s),
1.52±1.90 (4H, m), 2.35±2.51 (2H, m), 3.66 (3H, s),
3.96±4.19 (2H, m), 4.30 (1H, t, t, J=2.7, 9.9 Hz), 5.02
(1H, d, d, J=1.5, 10.2 Hz), 5.09 (1H, d, d, J=1.5,
15.6 Hz), 5.74 (1H, d, d, d, J=6.9, 10.2, 15.6 Hz). 13C
NMR d: À4.6, À4.4, À4.3, À4.0, 17.9, 18.2, 25.8, 25.9,
42.0, 45.2, 51.6, 65.1, 68.3, 71.8, 114.6, 141.3, 172.5. MS
(m/z) 431 (M+ÀCH3), 389, 317, 243, 203, 171 (100%).
HRMS calcd for C21H43O5Si2 (M+ÀCH3) 431.2649
found 431.2596. [a]2d4 À13.9ꢀ (c 0.82, CHCl3).
1
1
(neat) 1732, 1157, 1090 cmÀ1. H NMR d: 0.03 (3H, s),
0.04 (3H, s), 0.06 (3H, s), 0.07 (3H, s), 0.88 (18H, s),
1.19 (9H, s), 1.54±1.92 (3H, m), 3.87 (1H, q, J=6.6 Hz),
4.04±4.25 (3H, m), 5.04 (1H, d, t, J=0.9, 10.2 Hz), 5.11
(1H, d, J=17.4 Hz), 5.78 (1H, d, d, d, J=7.2, 10.2,
17.4 Hz). 13C NMR d: À4.5, À4.3, À4.1, 18.1, 25.9, 26.0,
27.3, 36.7, 38.8, 46.8, 61.2, 66.6, 72.0, 114.5, 141.8,
178.6. MS (m/z) 401 (M+ÀC4H9), 245, 159, 93 (100%).
HRMS calcd for C20H41O4Si2 (M+ÀC4H9) 401.2543,
found 401.2517. [a]d24 À30.2ꢀ (c 1.59, CHCl3). To a stir-
red solution of the above-mentioned TBS ether of 26
(831 mg, 1.81 mmol) in MeOH (8 mL) at room tem-
perature was added 10 N NaOH (2.4 mL). The stirring
was continued for 11 h at room temperature. The reac-
tion mixture was quenched with saturated NH4Cl, dilu-
ted with AcOEt, washed with saturated NaCl, dried,
evaporated, and chromatographed on silica gel. Elution
with AcOEt:hexane (1:20) gave 27 (543 mg, 80%) as a
colorless oil and the syn-alcohol (54 mg, 8%). 27: IR
Methyl (5S,7R)-bis(tert-butyldimethylsilyl)oxy-3-oxo-8-
nonenoate (30). To a stirred solution of 29 (1.50 g,
3.4 mmol) in CH2Cl2 (160 mL) at room temperature was
added Dess±Martin reagent (8.20 g, 19.4 mmol). The
mixture was stirred at room temperature for 15 h, dilu-
ted with hexane, and ®ltered through Celite. The ®ltrate
was diluted with Et2O, washed with saturated NaCl,
dried, evaporated and chromatographed on silica gel.
Elution with AcOEt:hexane (1:20) gave 30 (1.00 g, 69%)
as a colorless oil. IR (neat) 1751, 1651, 1250, 1084 cmÀ1
.
1H NMR d: 0.01 (3H, s), 0.03 (3H, s), 0.06 (3H, s), 0.07
(3H, s), 0.85 (9H, s), 0.88 (9H, s), 1.58±1.81 (2H, m), 2.69
(2H, d, J=6.0 Hz), 3.47 (2H, d, J=1.8 Hz), 3.72 (3H, s),
4.06±4.19 (1H, m), 4.24 (1H, q, J=6.0 Hz), 5.05 (1H, d,
J=10.8 Hz), 5.13 (1H, d, J=17.4 Hz), 5.77 (1H, d, d, d,
J=6.6, 10.8, 17.4 Hz). 13C NMR d: À4.6, À4.5, À4.3,
À3.9, 18.0, 18.2, 25.9, 26.0, 46.3, 50.6, 50.9, 66.8, 71.8,
91.1, 114.7, 141.5, 167.5, 175.9. MS (m/z) 413
(M+ÀOCH3), 387, 243, 201, 171 (100%). HRMS calcd
for C21H41O4Si2 (M+ÀOCH3) 413.2543, found
413.2559. [a]2d4 À18.0ꢀ (c 1.02, CHCl3).
1
(neat) 3420, 1470, 1255, 1090, 1035 cmÀ1. H NMR d:
0.03 (3H, s), 0.06 (3H, s), 0.07 (3H, s), 0.09 (3H, s), 0.88
(9H, s), 0.89 (9H, s), 1.65±1.78 (2H, m), 1.78±1.96 (2H,
m), 3.66±3.78 (1H, m), 3.79±3.90 (1H, m), 3.92±4.02
(1H, m), 4.10 (1H, q, J=6.9 Hz), 5.05 (1H, br d,
J=10.5 Hz), 5.12 (1H, br d, J=17.1 Hz), 5.77 (1H, d, d,
d, J=6.9, 10.5, 17.1 Hz). 13C NMR d: À4.5, À4.4, À4.2,
À3.9, 18.3, 25.9, 26.0, 38.4, 45.7, 60.3, 69.5, 72.0, 114.6,
141.5. MS (m/z) 373 (M+À1), 73 (100%). HRMS calcd
for C19H41O3Si2 (M+À1) 373.2594, found 373.2627.
[a]2d7 À14.2ꢀ (c 0.60, CHCl3).
Methyl (Z,5S,7R)-bis(tert-butyldimethylsilyl)oxy-3-(tri-
¯uoromethanesulfonyl)oxy-2,8-nonadienoate (31). To a
stirred solution of 30 (500 mg, 1.1 mmol) in THF (6 mL)
at À5 ꢀC was added NaH (60% oil dispersion, 90 mg,
2.2 mmol) and stirring was continued at the same tem-
perature for 1 h. 2-Py-N-Tf2 (725 mg, 2.0 mmol) was
added at À5 ꢀC and the mixture was stirred at room
temperature for 7.5 h. The reaction mixture was quen-
ched with H2O, extracted with Et2O, washed with 10%
citric acid and saturated NaCl, dried, evaporated and
chromatographed on silica gel. Elution with Et2O:hex-
ane (1:50) gave 31 (492 mg, 85%) as a colorless oil. IR
Methyl (5S,7R)-bis(tert-butyldimethylsilyl)oxy-3-hydroxy-
8-nonenoate (29). To a stirred solution of (COCl)2
(0.23 mL, 2.62 mmol) in CH2Cl2 (3.6 mL) at À78 ꢀC was
added DMSO (0.37 mL, 5.24 mmol). The resulting mix-
ture was stirred at the same temperature for 30 min and
a solution of 27 (491 mg, 1.31 mmol) in CH2Cl2 (5 mL)
at À78 ꢀC was added. After being stirred at the same
temperature for 20 min, Et3N (1.46 mL, 10.48 mmol)
was added and the mixture was allowed to warm to
room temperature. The reaction mixture was diluted
with hexane, ®ltered through Celite, and evaporated to
give crude 28 (1.97 g) as a colorless oil, which was used
without further puri®cation. To a stirred solution of
diisopropylamine (3.7 mL, 26.7 mmol) in THF (55 mL)
at À78 ꢀC was added n-BuLi (1.53 M in hexane,
17.5 mL, 26.7 mmol). The mixture was stirred at À25 ꢀC
for 20 min and then re-cooled to À78 ꢀC. MeCOOMe
(2.1 mL, 26.7 mmol) was added at À78 ꢀC and the stir-
ring was continued at the same temperature for 1 h. A
solution of 28 (1.97 g) in THF (10 mL) was added
dropwise at À78 ꢀC and the mixture was stirred at the
same temperature for 1 h. The reaction mixture was
quenched with saturated NH4Cl, diluted with Et2O,
dried, evaporated and chromatographed on silica gel.
Elution with AcOEt:hexane (1:20) gave 29 (1.50 g, 63%
for 2 steps) as a pale yellow oil. IR (neat) 3511, 1736,
(neat) 1736, 1429, 1211, 1136 cmÀ1. H NMR d: 0.02
1
(3H, s), 0.03 (3H, s), 0.05 (3H, s), 0.07 (3H, s), 0.86 (9H,
s), 0.88 (9H, s), 1.73 (2H, t, J=6.0 Hz), 2.44 (1H, d, d,
J=7.8, 15.3 Hz), 2.63 (1H, d, d, J=4.8, 15.3 Hz), 3.76
(3H, s), 4.01±4.11 (1H, m), 4.54 (1H, q, J=6.3 Hz), 5.08
(1H, d, d, J=0.9, 10.2 Hz), 5.14 (1H, d, d, J=0.9,
17.6 Hz), 5.77 (1H, d, d, d, J=7.2, 10.2, 17.6 Hz), 5.82
(1H, s). 13C NMR d: À4.6, À4.2, À3.8, 18.0, 18.2, 25.8,
25.9, 43.4, 46.4, 52.0, 66.3, 71.5, 113.8, 115.2, 141.3,
156.1, 162.7, 175.9. MS (m/z) 519 (M+ÀC4H9), 465
(100%). HRMS calcd for C19H34O7F3SSi2 (M+ÀC4H9)
519.1516, found 519.1511. [a]2d4 +6.5ꢀ (c 1.02, CHCl3).
(Z,5S,7R)-Bis(tert-butyldimethylsilyl)oxy-3-(tri¯uorome-
thanesulfonyl)oxy-2,8-nonadien-1-ol (32). To a stirred
solution of 31 (45 mg, 0.077 mmol) in CH2Cl2 (0.7 mL)
at À78 ꢀC was added dropwise DIBAL (1.0 M solution

412
S. Hatakeyama et al. / Bioorg. Med. Chem. 9 (2001) 403±415
in toluene, 163 mL, 0.16 mmol). The resulting mixture
was stirred at À78 ꢀC for 30 min, quenched with 10 N
NaOH, extracted with CH2Cl2, and ®ltered through
Celite. The ®ltrate was washed with 10% citric acid and
saturated NaCl, dried, evaporated, and chromato-
graphed on silica gel. Elution with Et2O:hexane (1:5)
gave 32 (41 mg, 98%) as a colorless oil. IR (neat) 3373,
added. The resulting mixture was stirred at À50 ꢀC for
1 h, and quenched with H2O. CHCl3 (10.6 mL) and 5%
H2O2 (7.8 mL) were added at room temperature and the
mixture was stirred for 30 min. The reaction mixture was
diluted with CHCl3, washed with saturated Na2S2O3 and
H2O, dried, evaporated, and chromatographed on silica
gel. Elution with AcOEt:hexane (1:2) gave 35 (117 mg,
1
1414, 1217, 1140 cmÀ1. H NMR d: 0.02 (3H, s), 0.03
86%) as a colorless oil. IR (neat) 1467, 1253, 1083 cmÀ1
.
(3H, s), 0.06 (3H, s), 0.07 (3H, s), 0.87 (9H, s), 0.88 (9H,
s), 1.66 (1H, d, t, J=6.0, 14.1 Hz), 1.75 (1H, d, t, J=6.3,
13.8 Hz), 2.44 (1H, d, d, J=7.5, 15.0 Hz), 2.57 (1H, d, d,
J=4.8, 15.0 Hz), 4.00 (1H, quint, J=6.0 Hz), 4.15 (1H,
q, J=6.6 Hz), 4.22 (1H, d, d, J=6.9, 13.8 Hz), 4.28 (1H,
d, d, J=7.2, 13.5 Hz), 5.08 (1H, d, J=10.2 Hz), 5.14
(1H, d, J=17.4 Hz), 5.61 (1H, t, J=6.9 Hz), 5.78 (1H, d,
d, d, J=7.2, 10.2, 17.4 Hz). 13C NMR d: À4.6, À4.5,
À4.2, À3.7, 18.2, 25.8, 25.9, 42.5, 46.3, 56.9, 66.3, 71.6,
115.0, 123.1, 141.5, 146.8. MS (m/z) 491 (M+ÀC4H9),
437, 341, 209, 171, 75, 73 (100%). HRMS calcd
for C18H34O6F3SSi2 (M+ÀC4H9) 491.1567, found
491.1551. [a]2d4 +3.9ꢀ (c 1.29, CHCl3).
1H NMR d: À0.04 (3H, s), 0.00 (3H, s), 0.02 (3H, s),
0.04 (3H, s), 0.81 (9H, s), 0.88 (9H, s), 1.65±1.75 (1H,
m), 1.81±1.91 (1H, m), 2.16 (1H, br d, J=14.7 Hz), 2.33
(1H, br d, J=13.2 Hz), 3.15 (1H, d, t, J=6.6, 15.9 Hz),
3.38 (1H, d, t, J=8.7, 14.7 Hz), 4.11 (1H, br t, J=
4.2 Hz), 4.35 (1H, br q, J=4.2 Hz), 4.73 (1H, s), 5.15
(1H, s), 5.33 (1H, q, J=6.6 Hz), 7.41±7.54 (6H, m),
7.66±7.76 (1H, m). 13C NMR d: À4.9, À4.7, À4.6, 18.2,
18.3, 25.9, 31.0, 31.9, 44.9, 45.6, 67.5, 70.9, 110.3, 115.1,
115.2, 128.5, 128.7, 131.1, 131.2, 131.8, 132.5, 133.5,
141.0, 141.1, 147.8. MS (m/z) 582 (M+), 525, 393, 275,
132, 75 (100%). HRMS calcd for C33H51O3PSi2
582.3115, found 582.3098. [a]2d4 +2.9ꢀ (c 1.43, CHCl3).
(Z,3R,5S)-[3,5-Bis(tert-butyldimethylsilyl)oxy-2-methyl-
enecyclohexylidene]ethanol (33). Amixture of 32 (267
mg, 0.486 mmol), Ph3P (28 mg, 0.107 mmol), Et3N
(136mL, 0.972 mmol), and Pd(OAc)2 (22 mg, 0.097 mmol)
in DMF (10 mL) was stirred at room temperature for
24.5 h. The reaction mixture was extracted with Et2O,
washed with saturated NaCl, dried, evaporated and chro-
matographed on silica gel. Elution with AcOEt:hexane
(1:10) gave 33 (99.8 mg, 52%) as a colorless oil. IR
(1R,3aR,4S,7aR)-4-Hydroxy-1-[(S)-1-(3-methyl-3-trime-
thylsilyloxybutyloxy)ethyl] - 7a - methyloctahydro - 1H -
indene (36). To a stirred solution of OCT (2) (100 mg,
0.239 mmol) in CH2Cl2 (2.4 mL) at 0 ꢀC were added Et3N
(266 mL, 1.91 mmol) and TMSOTf (173 mL, 0.96 mmol).
The resulting mixture was stirred at 0 ꢀC for 1.5 h,
quenched with H2O, extracted with Et2O, dried, evapo-
rated, and chromatographed on silica gel. Elution with
AcOEt:hexane (1:10) gave the triTMS ether of OCT (2)
(186 mg, 75%) as a colorless oil. IR (neat) 1251,
1
(neat) 1464, 1254, 1092 cmÀ1. H NMR d: 0.05 (6H, s),
1
0.06 (6H, s), 0.87 (9H, s), 0.88 (9H, s), 1.43 (1H, br s),
1.74±1.88 (2H, m), 2.18 (1H, d, d, J=6.6, 12.9 Hz), 2.40
(1H, d, d, J=6.0, 12.9 Hz), 4.14±4.21 (3H, m), 4.39 (1H,
t, J=5.7 Hz), 4.75 (1H, t, J=1.2 Hz), 5.16 (1H, br
t, J=1.5 Hz), 5.32 (1H, t, J=6.9 Hz). 13C NMR d: À5.0,
À4.8, À4.7, 18.2, 18.3, 25.9, 44.7, 45.4, 59.8, 67.4,
71.4, 110.7, 126.7, 139.5, 147.8. MS (m/z) 367
(M+ÀCH2OH), 341, 249, 73 (100%). HRMS calcd for
C20H39O2Si2 (M+ÀCH2OH) 367.2488, found 367.2485.
[a]2d4 À21.2ꢀ (c 0.77, CHCl3).
1075 cmÀ1. H NMR d: 0.10 (9H, s), 0.12 (18H, s), 0.53
(3H, s), 1.15 (3H, d, J=6.0 Hz), 1.23 (6H, s), 1.20±2.10
(15H, m), 2.23 (1H, d, d, J=7.8, 13.8 Hz), 2.46 (1H, d,
d, J=3.8, 13.8 Hz), 2.84 (1H, br d, J=12.3 Hz), 3.20
(1H, br quint, J=6.0 Hz), 3.32 (1H, d, t, J=6.2, 8.7 Hz),
3.65 (1H, d, t, J=6.6, 8.7 Hz), 4.18 (1H, m), 4.37 (1H, d,
d, J=3.9, 6.6 Hz), 4.90 (1H, d, J=2.4 Hz), 5.20 (1H, d,
J=1.2 Hz), 6.05 (1H, d, J=11.1 Hz), 6.27 (1H, d,
J=11.1 Hz). 13C NMR d: 0.25, 0.3, 2.7, 12.6, 19.4, 22.2,
23.4, 25.8, 30.0, 30.5, 39.8, 44.6, 44.7, 44.9, 45.9, 56.3,
57.5, 65.0, 67.3, 71.7, 73.1, 78.1, 111.6, 118.1, 123.4,
135.0, 141.0, 148.0. [a]2d4 +14.9ꢀ (c 0.37, CHCl3). O3 was
bubbled into a stirred mixture of the above-mentioned
triTMS ether of OCT (2) (185 mg, 0.292 mmol) and
NaHCO3 (100 mg, 1.19 mmol) in CH2Cl2 (4 mL) and
MeOH (1 mL) at À78 ꢀC for 30 min. The excess O3 was
removed by bubbling argon. The resulting mixture was
diluted with MeOH (5 mL) and NaBH4 (200 mg,
5.263 mmol) was added at 0 ꢀC. After being stirred at
0 ꢀC for 1 h, the reaction mixture was extracted with
CH2Cl2, washed with saturated NaCl, dried, evaporated
and chromatographed on silica gel. Elution with
AcOEt:hexane (1:8) gave 36 (73.4 mg, 72%) as a color-
(Z,3R,5S)-2-[3,5-Bis(tert-butyldimethylsilyl)oxy-2-methyl-
enecyclohexylidene]-1-chloroethane (34). Amixture of
NCS (75 mg, 0.564 mmol) and DMS (43 mL, 0.564 mmol)
in CH2Cl2 (4.4 mL) was stirred at 0 ꢀC for 40 min. This
solution (1.83 mL) was then added dropwise to a stirred
solution of 33 (112 mg, 0.282 mmol) in CH2Cl2 (0.9 mL)
at À20ꢀC. After being stirred at room temperature for 1 h,
the reaction mixture was diluted with hexane, washed with
H2O and saturated NaCl, dried, evaporated, and chro-
matographed on silica gel. Elution with AcOEt:hexane
(1:10) gave practically pure 34 (97 mg, 83%) as a pale
yellow oil, which was used without further puri®cation.
less oil. IR (neat) 3455, 1250, 1169, 1036 cmÀ1 1H
.
(Z,3R,5S)-2-[3,5-Bis(tert-butyldimethylsilyl)oxy-2-methyl-
enecyclohexylidene]ethyl]diphenylphosphine oxide (35).
To a stirred solution of HPPh2 (195 mL, 1.05 mmol) in
THF (3.8 mL) at 0 ꢀC was added n-BuLi (1.53 M in hex-
ane, 684 mL, 1.05 mmol) and the stirring was continued
for 10 min. The mixture was cooled to À50 ꢀC and a
solution of 34 (97 mg, 0.23 mmol) in THF (1.2 mL) was
NMR d: 0.09 (9H, s), 0.91 (3H, s), 1.13 (3H, d,
J=6.3 Hz), 1.22 (6H, s), 1.25±2.14 (13H, m), 3.18 (1H,
d, q, J=6.3, 8.7 Hz), 3.32 (1H, d, d, d, J=6.6, 8.1,
9.0 Hz), 3.64 (1H, d, d, d, J=6.3, 8.1, 9.0 Hz), 4.08 (1H,
br q, J=2.4 Hz). 13C NMR d: 2.7, 14.2, 17.4, 19.2, 22.5,
25.7, 30.5, 33.6, 39.7, 41.0, 44.6, 52.6, 57.6, 64.9, 69.3,
73.2, 77.9. [a]2d5 +38.4ꢀ (c 0.37, CHCl3).

S. Hatakeyama et al. / Bioorg. Med. Chem. 9 (2001) 403±415
413
(1R,3aR,4S,7aR)-4-Hydroxy-1-[(S)-1-(3-methyl-3-tri-
methylsilyloxybutyloxy)ethyl]-7a-methyloctahydro-1H-
inden-4-one (37). To a stirred mixture of 36 (20 mg,
0.056 mmol) and molecular sieves (4 A, 24 mg) in CH2Cl2
(3.1 mL) at room temperature was added NMO (13 mg,
0.107 mmol). The resulting mixture was stirred at room
temperature for 1 h. TPAP (1.3 mg, 0.004 mmol) was
added. The resulting mixture was stirred at room tem-
perature for 2 h, diluted with CH2Cl2 and ®ltered with
Celite. The ®ltrate was evaporated and chromato-
graphed on silica gel. Elution with AcOEt:hexane (1:10)
gave 37 (24 mg, 96%) as a colorless oil. IR (neat) 1716,
colorless oil. IR (neat) 1371, 1252, 1080 cmÀ1. 1H NMR
d: 0.01±0.08 (12H, s), 0.10 (12H, s), 0.51 (3H, s), 0.87
(9H, s), 0.88 (9H, s), 1.16 (3H, d, J=6.0 Hz), 1.23 (3H, s),
1.25 (3H, s), 1.42±2.03 (15H, m), 2.21 (1H, d, d, J=3.3,
12.9Hz), 2.43 (1H, d, d, J=3.3, 12.9 Hz), 2.81 (1H, d, d,
J=4.2, 12.0 Hz), 3.20 (1H, quint, J=6.0 Hz), 3.33 (1H, d,
t, J=6.3, 15.0 Hz), 3.65 (1H, d, t, J=6.3, 15.0 Hz), 4.18
(1H, d, d, t, J=3.3, 7.5, 15.0 Hz), 4.38 (1H, d, d, J=3.9,
6.6 Hz), 4.87 (1H, d, J=2.4 Hz), 5.18 (1H, d, J=2.4 Hz),
6.00 (1H, d, J=11.1 Hz), 6.22 (1H, d, J=11.1 Hz). 13C
NMR d: À5.0, À4.7, À4.6, 2.7, 12.4, 18.4, 19.4, 22.2,
23.5, 29.1, 29.8, 30.5, 40.0, 44.6, 44.8, 44.9, 46.2, 56.3,
57.5, 65.0, 67.6, 72.1, 73.2, 76.7, 77.1, 77.5, 78.1, 111.1,
118.1, 123.3, 135.4, 140.6, 148.6. MS (m/z) 718 (M+),
586, 248, 131 (100%). HRMS calcd for C41H78O4Si3
718.5208, found 718.5192. [a]2d5 +12.9ꢀ (c 1.60, CHCl3).
1
1454, 1369, 1251, 1036 cmÀ1. H NMR d: 0.09 (9H, s),
0.62 (3H, s), 1.17 (3H, d, J=6.0 Hz), 1.22 (6H, s), 1.48±
2.06 (11H, m), 2.15±2.33 (2H, m), 2.44 (1H, d, d, J=7.5,
11.4 Hz), 3.22 (1H, d, q, J=6.0, 7.5 Hz), 3.31 (1H, d, d,
d, J=6.6, 8.1, 9.3 Hz), 3.65 (1H, d, d, J=6.6, 8.1 Hz).
13C NMR d: 2.7, 13.3, 19.1, 19.3, 23.9, 25.2, 30.45, 30.5,
38.2, 41.0, 44.5, 48.9, 57.5, 61.9, 65.2, 73.1, 211.9.
(5Z,7E,1S,3S,20S)-20-(3-Hydroxy-3-methylbutyloxy)-
9,10-secopregna-5,7,10(19)-trien-1,3-diol (3). Amixture
of 38 (12.6 mg, 0.017 mmol) and TBAF (1.0 M solution
in THF, 70 mL, 0.070 mmol) in THF (0.3 mL) was stir-
red at room temperature for 18 h. The reaction mixture
was quenched with H2O (3 mL), extracted with AcOEt,
washed with saturated NaCl, dried, and evaporated.
The residue was puri®ed by preparative TLC developed
with AcOEt:hexane (1:15) to give 3 (7.7 mg, 100%) as a
(5Z,7E,1S,3S,20S)-1,3-Bis(tert-butyldimethylsilyloxy) -
20 - (3 - methyl - 3 - trimethylsilyloxybutyloxy) - 9,10 - seco-
pregna-5,7,10(19)-triene (38). To a stirred solution of 21
(43.3 mg, 0.0745 mmol) in THF (0.7 mL) at À78 ꢀC was
added n-BuLi (1.58 M solution in hexane, 47 mL,
0.075 mmol). The resulting mixture was stirred at À78 ꢀC
for 8 min and a solution of 37 (13.1 mg, 0.037 mmol) in
THF (2 mL) was added dropwise at À78 ꢀC. The reaction
mixture was stirred at À78 ꢀC for 6 h, quenched with
saturated NH4Cl (5 mL), extracted with CH2Cl2,
washed with H2O and saturated NaCl, dried, and eva-
porated. The residue was puri®ed by preparative TLC
developed with AcOEt:hexane (1:4) to give 38 (12.6 mg,
45%) as a colorless oil. IR (neat) 1644, 1471, 1370,
1
colorless oil. IR (neat) 3319, 1453, 1371, 1077cmÀ1. H
NMR d: 0.53 (3H, s), 1.19 (3H, d, J=6.0 Hz), 1.24 (6H, s),
1.44±1.74 (12H, m), 1.84±2.06 (2H, m), 2.12±2.26 (2H, m),
2.25 (1H, br s), 2.44 (1H, d, d, J=5.1, 13.2 Hz), 2.56 (1H,
br d, d, J=2.7, 13.2Hz), 3.25 (1H, quint, J=6.3 Hz), 3.48
(1H, d, t, J=6.0, 9.3 Hz), 3.82 (1H, br s), 3.85 (1H, d, t,
J=5.7, 9.3 Hz), 4.06 (1H, br q, J=5.1 Hz), 4.32 (1H, br q,
J=3.9Hz), 5.25 (1H, d, J=1.8Hz), 5.55 (1H, br s), 6.28
(1H, d, J=11.1 Hz), 6.68 (1H, d, J=11.1 Hz). 13C NMR
d: 12.8, 18.9, 19.4, 22.3, 23.3, 25.7, 29.0, 29.2, 29.4, 39.7,
40.7, 41.6, 44.9, 45.6, 56.2, 57.2, 65.6, 68.3, 70.6, 73.3,
78.9, 113.1, 117.5, 125.5, 132.1, 142.4, 147.2. MS (m/z)
418 (M+), 400, 44 (100%). HRMS calcd for C26H42O4
418.3083, found 418.3070. [a]1d7 À33.0ꢀ (c 0.39, EtOH).
UV lmax 264 nm lmin 228 nm.
1
1250, 1075 cmÀ1. H NMR d: 0.07 (6H, s), 0.08 (3H, s),
0.10 (12H, s), 0.54 (3H, s), 0.89 (9H, s), 0.94 (9H, s), 1.15
(3H, d, J=6.3Hz), 1.23 (6H, s), 1.42±1.76 (12H, m), 1.84±
2.04 (3H, m), 2.12±2.26 (2H, m), 2.43 (1H, br d, d, J=2.7,
12.3Hz), 2.83 (1H, br d, J=11.1 Hz), 3.12 (1H, q,
J=6.6 Hz), 3.21 (1H, quint, J=6.6 Hz), 3.65 (1H, q,
J=6.6 Hz), 3.66±3.76 (1H, m), 3.95 (1H, br d, J=11.1 Hz),
4.93 (1H, t, J=2.4 Hz), 5.38 (1H, t, J=2.4Hz), 6.01 (1H,
d, J=11.4 Hz), 6.27 (1H, d, J=11.4 Hz). 13C NMR d:
À5.0, À4.9, À4.6, 2.7, 12.5, 18.3, 18.6, 19.4, 22.2, 23.5,
25.7, 26.0, 29.1, 29.8, 30.5, 39.7, 44.6, 44.8, 46.6, 47.0,
56.3, 57.5, 65.0, 68.8, 70.3, 78.0, 110.0, 117.9, 123.0,
134.9, 142.0, 148.1. MS (m/z) 718 (M+), 703, 75
(100%). HRMS calcd for C41H78O4Si3 718.5208, found
718.5201.
(5Z,7E,1R,3S,20S)-20-(3-Hydroxy-3-methylbutyloxy)-
9,10-secopregna-5,7,10(19)-trien-1,3-diol (4). Amixture
of 39 (10.6 mg, 0.014 mmol) and TBAF (1.0 M solution
in THF, 209 mL, 0.209 mmol) in toluene (0.5 mL) was
stirred at 105 ꢀC for 2 h, diluted with AcOEt, washed
with H2O and saturated NaCl, dried, and evaporated.
The residue was puri®ed by preparative TLC developed
with CH2Cl2:EtOH (9:1) to give 4 (3.5 mg, 60%) as a
colorless oil. IR (neat) 3367, 2966, 2933, 2873, 1448,
(5Z,7E,1R,3S,20S)-1,3-Bis(tert-butyldimethylsilyloxy)-
20 - (3 - methyl - 3 - trimethylsilyloxybutyloxy) - 9,10 - seco-
pregna-5,7,10(19)-triene (39). To a stirred solution of 35
(44.3 mg, 0.076 mmol) in THF (0.7 mL) at À78 ꢀC was
added n-BuLi (1.53 M solution in hexane, 50 mL,
0.076 mmol). The resulting mixture was stirred at
À78 ꢀC for 15 min and a solution of 37 (14.2 mg,
0.04 mmol) in THF (0.5 mL) was added dropwise at
À78 ꢀC. The reaction mixture was stirred at À78 ꢀC for
5 h, quenched with saturated NH4Cl, extracted with
CH2Cl2, washed with H2O and saturated NaCl, dried,
evaporated, and chromatographed on silica gel. Elution
with AcOEt:hexane (1:30) gave 39 (9.4 mg, 33%) as a
1
1375, 1151, 1090, 1055 cmÀ1. H NMR d: 0.53 (3H, s),
1.19 (3H, d, J=6.1 Hz), 1.23 (6H, s), 2.29 (1H, d, d,
J=7.4, 13.2 Hz), 2.61 (1H, d, d, J=3.7, 13.6 Hz), 2.83
(1H, d, d, J=3.7, 11.8 Hz), 3.25 (1H, m), 3.48 (1H, d, t,
J=5.7, 9.6 Hz), 3.84 (1H, d, t, J=5.7, 9.2 Hz), 4.15±4.29
(1H, m), 4.39±4.48 (1H, m), 4.98±5.01 (1H, m), 5.30±
5.33 (1H, m), 6.01 (1H, d, J=11.4 Hz), 6.38 (1H, d,
J=11.4 Hz). MS (m/z) 418 (M+), 134 (100%). [a]2d4
À13.0ꢀ (c 0.17, EtOH). UV lmax 264 nm lmin 228 nm.
Binding assay for rat plasma DBP. Competitive displace-
ment of [23,24-3H]-25-hydroxyvitamin D3 (25OHD3)

414
S. Hatakeyama et al. / Bioorg. Med. Chem. 9 (2001) 403±415
from vitamin D-de®cient rat plasma DBP by 1,25(OH)2
D3 (1), OCT (2) and A-ring diastereomers (3, 4, and 5)
was determined under equilibrium ligand-binding condi-
tions.22 [23,24-3H]-25OHD3 (speci®c activity; 3.3 TBq/
mmol, obtained from Amersham Co., Buckinghamshire,
82 fmol) in EtOH (50 mL) was mixed with increasing
amounts of analogues (0.24±1000 ng) in EtOH (100 mL).
Vitamin D-de®cient rat plasma (1 mL), diluted 1:70,000
with freshly prepared barbital acetate bu€er (3.5 mmol
AcOH, 3.5 mmol sodium barbiturate and 0.13 mol NaCl,
pH 8.6), was added. The resulting mixtures were incu-
bated at 0 ꢀC for 1 h, treated with dextran charcoal, vor-
texed, and centrifuged at 3000 rpm for 15 min at 4 ꢀC.
Radioactivity of 1 mL of each supernatant was mea-
sured with an Aloka LSC-700.
(pGVB2 vector, Toyo Ink Co., Ltd., Tokyo) inserted
with a rat 25-hydroxyvitamin D3-24-hydroxylase gene
promoter (À291/+9) including two vitamin D-respon-
sive elements24 or a human osteocalcin gene promoter
(À848/+10) including vitamin D-responsive element25
and 0.25 mg of the pRL-CMV vector (Toyo Ink Co.,
Ltd., Tokyo) as an internal control using the Tfx-50
reagent (Promega Corp., Tokyo). The cells were incu-
bated with 1,25(OH)2D3 (1), or analogues (2, 3, 4, and
5) (10À8 M) for 2 d. The luciferase activities of the cell
lysates were measured with a luciferase assay system
(Toyo Ink Co., Ltd., Tokyo) according to the manu-
facturer's instructions. Transactivation measured by
luciferase activity was standardized with the luciferase
activity of the same cells determined by the Sea Pansy
luciferase assay system as a control (Toyo Ink Co., Ltd.,
Tokyo).26 Each set of experiments was repeated at least
three times, and the results are presented in terms of
fold induction as mean Æ standard errors.
Binding assay for calf-thymus VDR. Displacement of
[26,27-3H]-1,25(OH)2D3 (speci®c activity; 6.7 TBq/mmol,
obtained from Amersham Co., Buckinghamshire) from
calf-thymus cytosol receptor (Yamasa Shoyu Co., Ltd.,
Chiba) by 1,25(OH)2D3 (1), or analogues (2, 3, 4, and 5)
was determined by the reported method.23 Samples
containing calf-thymus cytosol receptor solution
(500 mL), prepared with phosphate bu€er (0.3 M KCl,
0.05 M K2HPO4, pH 7.4), were mixed with increasing
amounts of 1 (0.25±256 pg) or 2, 3, 4 and 5 (0.25±
16384 pg) in EtOH (20 mL) and the samples were incu-
bated at 20 ꢀC for 1 h. [26,27-3H]-1,25(OH)2D3 (34 fmol)
in EtOH (25 mL) was added. The resulting mixture was
incubated at 20 ꢀC for 1 h, treated with dextran charcoal,
vortexed, and centrifuged at 3000 rpm for 10 min at 4 ꢀC.
Radioactivity of 100 mL of each supernatant was mea-
sured with an Aloka LSC-700.
Acknowledgements
We are grateful to Associate Professor David Horne,
Oregon State University, for helpful discussions.
References and Notes
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