Absolute structure and total synthesis of lipogrammistin-A, a lipophilic ichthyotoxin of the soapfish

Article abstract of DOI:10.1021/jo9722461

Lipogrammistin-A (1b) was isolated as an ichthyotoxic and hemolytic constituent of the skin mucus of the grammistid fish Aulacocephalus temmincki. Its absolute stereochemistry was established by chemical degradation and total synthesis. The stereochemistry of the 2-methylbutyryl moieties attached to N9 and N15 was determined to be S by HPLC analysis of a diastereomeric derivative. The stereochemistry of the remaining C4 position was elucidated to be S by a total synthesis of the two diastereomers (4S)- and (4R)-1.

Full text of DOI:10.1021/jo9722461

J . Org. Chem. 1998, 63, 3925-3932
3925
Absolu te Str u ctu r e a n d Tota l Syn th esis of Lip ogr a m m istin -A, a
Lip op h ilic Ich th yotoxin of th e Soa p fish
Hiroyuki Onuki,† Kei Ito,‡ Yoshimasa Kobayashi, Nobuaki Matsumori,§ and
Kazuo Tachibana*
Department of Chemistry, School of Science, The University of Tokyo, 7-3-1 Hongo,
Bunkyo-ku, Tokyo 113-0033, J apan
Nobuhiro Fusetani
Laboratory of Aquatic Natural Products Chemistry, Graduate School of Agricultural and Life Sciences,
The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo 113-0032, J apan
Received December 11, 1997
Lipogrammistin-A (1b) was isolated as an ichthyotoxic and hemolytic constituent of the skin mucus
of the grammistid fish Aulacocephalus temmincki. Its absolute stereochemistry was established
by chemical degradation and total synthesis. The stereochemistry of the 2-methylbutyryl moieties
attached to N9 and N15 was determined to be S by HPLC analysis of a diastereomeric derivative.
The stereochemistry of the remaining C4 position was elucidated to be S by a total synthesis of the
two diastereomers (4S)- and (4R)-1.
In tr od u ction
mistins isolated from G. sexlineatus were shown to be
simple peptides containing 24 and 25 amino acids,
More than 10 species of marine fishes possess ichthyo-
toxic components in their skin secretions.1-3 These toxic
secretions clearly function as a chemical defense against
predators and other enemies. However, the chemical
components of these ichthyotoxins have been elucidated
in only a very few cases; e.g., pahutoxin, a choline ester
of 3-acetoxypalmitic acid from the Hawaiian boxfish
Ostracion lentiginosus,4,5 and pardaxins (peptides) and
pavoninins (steroid glycosides) from the two soles Par-
dachirus pavoninus and P. marmoratus.6-10
respectively.14
In addition to grammistins, the skin secretion of D.
bifasciatum also contains lipophilic ichthyotoxins that are
positive to Dragendorff’s test.13 We previously reported
the isolation and gross structure of the lipophilic ich-
thyotoxin lipogrammistin-A (1) from the skin secretion
of D. bifasciatum.15 Lipogrammistin-A was considered
Soapfish, another well-known ichthyocrinotoxic family,
are known to secrete copious amounts of mucus, which
produces a soaplike foam in water. Hashimoto et al. have
reported the peptidic ichthyotoxin named grammistins
in the four typical grammistid fishes Pogonoperca punc-
tata,11 Grammistes sexlineatus, Diploprion bifasciatum,
and Aulacocephalus temmincki.12,13 Recently, two gram-
to be an 18-membered polyamine lactam on the basis of
spectral data. However, the three asymmetric centers
at C4, C2′′, and C2′′′ in 1 were not determined since they
were separated by more than seven bonds, which pre-
vented the application of spectroscopic methods such as
the nuclear Overhauser effect (NOE). NMR data sug-
gested that 1 exists in solution as a mixture of four
conformers probably due to conformational changes
around tertiary amide linkages, which further hampered
the configurational analysis of 1 by NMR.
* To whom correspondence should be addressed. Tel. and Fax: +81-
3-5800-6898. E-mail: ktachi@chem.s.u-tokyo.ac.jp.
† Present Address: Central Research Laboratory, Nippon Suisan
Kaisha, Ltd., 559-6 Kitanomachi, Hachioji, Tokyo 192-0906, J apan.
‡ Present Address: Development Center, Kansai Paint, Co. Ltd.,
4-17-1 Higashi-Yawata, Hiratsuka, Kanagawa 254-0015, J apan.
§ Present address: Department of Biotechnology, Graduate School
of Agricultural and Life Sciences, The University of Tokyo, 1-1-1 Yayoi,
Bunkyo-ku, Tokyo 113-0032, J apan.
(1) Tachibana, K. In Bioorganic Marine Chemistry; Scheuer, P. J .,
Ed.; Springer-Verlag: Berlin, 1988; Vol. 2, pp 117-138.
(2) Nair, M. S. R. In Handbook of Natural Toxins; Tu, A. T., Ed.;
Marcel Dekker: New York, 1988; Vol. 3, pp 211-226.
(3) Hashimoto, Y. Marine Toxins and Other Bioactive Marine
Metabolites; J apan Scientific Societies Press: Tokyo, 1979; pp 312-
332.
Therefore, we decided to determine the absolute ster-
eochemistry of lipogrammistin-A by chemical degradation
(4) Boylan, D. B.; Scheuer, P. J . Science 1967, 155, 52-56.
(5) Yoshikawa, M.; Sugimura, T.; Tai, A. Agric. Biol. Chem. 1989,
53, 37-40.
(11) (a) Hashimoto, Y.; Kamiya, H. Toxicon 1969, 7, 65-70. (b)
Oshima, Y.; Hashimoto, Y. In Animal, Plant, and Microbial Toxins;
Ohsaka, A., Ed.; Plenum: New York, 1976; Vol. 1, pp 297-301.
(12) Randall, J . E.; Aida, K.; Hibiya, T.; Matsuura, N.; Kamiya, H.;
Hashimoto, Y. Publ. Seto Mar. Biol. Lab. 1971, 19, 157-190.
(13) Oshima, Y.; Shiomi, K.; Hashimoto, Y. Bull. J pn. Soc. Sci. Fish.
1974, 40, 223-230.
(14) Shiomi, K.; Igarashi, T.; Shimakura, K.; Nagashima, Y. Ab-
stracts of Papers, Meeting of the J apanese Society of Fisheries Science;
J apanese Society of Fisheries Science: Tokyo, 1997: Abstract 1005.
(15) Onuki, H.; Tachibana, K.; Fusetani, N. Tetrahedron Lett. 1993,
34, 5609-5612.
(6) Tachibana, K.; Sakaitani, M.; Nakanishi, K. Science 1984, 226,
703-705.
(7) Tachibana, K.; Sakaitani, M.; Nakanishi, K. Tetrahedron 1985,
41, 1027-1037.
(8) Thompson, S. A.; Tachibana, K.; Nakanishi, K.; Kubota, I. Science
1986, 233, 341-343.
(9) Thompson, S. A.; Tachibana, K.; Kubota, I.; Zlotkin, E. In Peptide
Chemisty 1987; Shiba, T., Sakakibara, S., Eds.; Protein Research
Foundation: Osaka, 1988; pp 127-132.
(10) Tachibana, K.; Gruber, S. H. Toxicon 1988, 26, 839-853.
S0022-3263(97)02246-9 CCC: $15.00 © 1998 American Chemical Society
Published on Web 05/15/1998

3926 J . Org. Chem., Vol. 63, No. 12, 1998
Onuki et al.
Sch em e 1
as well as by the total synthesis of possible diastereomers.
This paper describes the complete structural elucidation
of lipogrammistin-A based on a total synthesis, as well
as the isolation of 1 from another soapfish A. temmincki.
possible solution to this problem seemed to involve the
total synthesis of (4R)- and (4S)-lipogrammistin-A. There-
fore, we planned the total synthesis of both the 4R and
4S diastereomers (1a and 1b) as depicted in Scheme 1.
The crucial step is the construction of an 18-membered
lactam ring, which should be achieved by the intramo-
lecular reductive amination of amino aldehydes 2a and
2b. These aldehydes can be built by the condensation of
optically active â-amino carboxylic acid (+)- or (-)-3 with
polyamine 4 bearing two (S)-2-methylbutyryl side chains.
Resu lts
Isola tion of Lip ogr a m m istin -A (1) fr om A. tem -
m in cki. Building upon our previous report, which
described the isolation and structure of lipogrammistin-A
from D. bifasciatum, in this study we investigated
another soapfish, A. temmincki.15 Isolation of lipophilic
ichthyotoxins was carried out as reported for D. bifas-
ciatum. Mucus (0.75 g) was scratched from the skin of
one specimen of A. temmincki that had been collected off
Izu Peninsula and extracted with acetone. The extract
was partitioned between water and ethyl acetate. The
organic layer was fractionated on a silica gel column
(CHCl3-MeOH 98:2) with guidance of the ichthyotoxicity
of the killifish Oryzias latipes. Further purification was
carried out by reversed-phase HPLC to furnish 3.0 mg
of lipogrammistin-A (yield, 0.4% of wet mucus). This
ichthyotoxin was indistinguishable from lipogrammis-
tin-A isolated from D. bifasciatum on silica gel TLC,
reversed-phase HPLC, and 1H and 13C NMR spectra.
Therefore, the following degradation experiments were
carried out for 1 from D. bifasciatum.
Ster eoch em istr y of th e 2-Meth ylbu tyr yl Moiety.
To determine the configuration of 2-methylbutyric acid,
1 was hydrolyzed under acidic conditions (3 N HCl, 5 h,
110 °C), and the hydrolysate was derivatized with the
chiral reagent (S)-1-(1-naphthyl)ethylamine to give the
corresponding amide, which possessed dual chiral car-
bons.16 Comparison of the amide with authentic diaster-
eomeric amides by HPLC led to the identification of (S)-
2-methylbutyric acid as the dominant enantiomer from
natural 1 (78% diastereomeric excess). A small amount
of the R enantiomer is considered to arise during acid
hydrolysis. We also observed the same degree of race-
mization when a model compound (17) was hydrolyzed
under similar conditions. Therefore, the stereochemistry
of the 2-methylbutyric acid as components of lipogram-
mistin-A was originally S, assuming that an exceeding
discrimination between the two amide moieties is im-
probable in the hydrolysis. It was accordingly concluded
that the absolute stereochemistry of the two 2-methyl-
butyric acyl moieties in 1 was S.
The â-amino acid moiety was synthesized as illustrated
in Scheme 2. The regioselective reduction of diyne 517
by LiAlH4 gave (E)-allyl alcohol 6. Sharpless asymmetric
epoxidation using (+)-DET afforded the chiral epoxide
(+)-7,18 while (-)-7 was obtained from 6 with (-)-DET.
Reduction of the triple bond by Lindlar hydrogenation
gave (+)-8, which was subjected to regioselective hydro-
genation with Red-Al to give 1,3-diol (-)-9 in good yield.
Selective protection of a primary hydroxyl group with
TBDPS, followed by mesylation and inversion with NaN3,
furnished the corresponding azide (+)-10. Selective
reduction of the azide in the presence of the double bond
was successfully carried out using Ph3P in aqueous
THF.19 Protection of the amino group with a tert-
butoxycarbonyl group (Boc) provided (+)-11. Removal of
a silyl group with n-Bu4NF afforded the primary alcohol
(+)-12, which was subjected to sequential oxidation
(Swern oxidation, NaClO2) to yield the carboxylic acid
(+)-3. The enantiomer (-)-3 was similarly synthesized
from the enantiomeric epoxide (-)-8. Although the
absolute stereochemistry of each enantiomer ((+)- and
(-)-3) could be predicted from the enantioselectivity of
Sharpless asymmetric epoxidation, the optical purity of
3 was determined to be 95% ee by a modification of
Mosher’s method.20,21
(17) Eiter, K.; Lieb, F.; Disselnko¨tter, H.; Oediger, H. Liebigs Ann.
Chem. 1978, 658-671.
(18) Katsuki, T.; Sharpless, K. B. J . Am. Chem. Soc. 1980, 102,
5974-5976.
(19) Nagarajan, S.; Ganem, B. J . Org. Chem. 1987, 52, 5044-5046.
(20) (a) Kusumi, T.; Fukushima, T.; Ohtani, I.; Kakisawa, H.
Tetrahedron Lett. 1991, 32, 2939-2942. (b) Kusumi, T. Yuki Gosei
Kagaku Kyokaishi 1993, 51, 462-470.
(21) To determine the absolute configuation of carboxylic acid 3, we
converted it to MTPA derivative 11 by a three-step sequence ((1)
TMSCHN2, (2) TFA, (3) (+)-(R)-MTPAOH, DCC). Assignment of all
proton signals of each MTPA derivative was established by the HH-
COSY spectra. The result indicated that the absolute configuration of
the original carboxylic acid (-)-3 was R and its optical purity was 95%
ee, judging from a ratio of the integration for methoxy protons of 13a
and 13b.
Tota l Syn th esis of Tw o C4-Dia ster eom er s for
Lip ogr a m m istin -A (1). Since the stereochemistry of
the two 2-methylbutyryl moieties was determined, one
chiral center (C4) remained to be elucidated. The only
(16) Bergot, B. J .; Anderson, R. J .; Schooley, D. A.; Henrick, C. A.
J . Chromatogr. 1978, 155, 97-105.

Total Synthesis of Lipogrammistin-A
J . Org. Chem., Vol. 63, No. 12, 1998 3927
Sch em e 2
Sch em e 3
Sch em e 4
Synthesis of the polyamine moiety was carried out as
depicted in Scheme 3. Cyanoethylation of cadaverine
(14) provided monoalkylated diamine 15, which was then
converted to asymmetric diamine 16 by Michael addition
with ethyl acrylate.22 Acylation of 16 with (S)-2-meth-
ylbutyric acid gave diamide 17, which yielded primary
amine 4 upon subsequent hydrogenation over PtO2.
The 4R diastereomer 1a was synthesized by condensa-
tion of carboxylic acid (-)-3 with amine 4 (Scheme 4).
The resulting amide 18a was converted to aldehyde 19a
by successive reduction with LiBH4 followed by oxidation
with SO3-pyridine in DMSO. After deprotection of the
Boc group with TFA, cyclization was carried out by
reduction of the resultant Shiff base to furnish 1a in a
modest yield. After successive purification by alumina
column chromatography and reversed-phase HPLC, syn-
(22) Yamamoto, H.; Maruoka, K. J . Am. Chem. Soc. 1981, 103,
6133-6136.

3928 J . Org. Chem., Vol. 63, No. 12, 1998
Onuki et al.
as shown by the dependence of its NMR-signal on
temperature.15 In general, tertiary amides undergo
conformational alteration in solution due to the restricted
rotation of their amide bonds. The presence of these four
conformers for lipogrammistin-A could be attributed not
only to amide bond rotation but also to conformational
exchanges in the 18-membered ring, which was inferred
from the following observations: (a) Several signals
observed as multiplets at 300 K were sharpened at 333
K, and some became singlets. In particular, the carbon
on the 2-methylbutyryl moieties showed this feature. (b)
Some split signals at 300 K became much broader at 333
K (their coalescence points were around 333 K), which
was typically observed for carbons residing on the
polyamine ring but was also seen even for those in the
fatty acyl chain, such as C1′, C2′, and C3′. These
phenomena appeared to imply that there were two rate
constants for the conformational change; the faster one
is due to alteration of the tertiary amide and the slower
one is due to ring conformation. However, on the basis
of our intensive analysis of the 13C spectra of 1 taken at
various lower temperatures (-30 to +5 °C) in CD3OD-
1% TFA or pyridine-d5, we concluded that the two rate
constants were almost identical. In other words, the ring
motion is controlled by alteration of the amide bonds. The
spectra showed that the differences in the 13C-chemical
shifts among the conformers were smaller for carbons in
the methylbutyryl moieties (∼0.2 ppm) than for those in
the ring portions (0.5-2.1 ppm).
Lipogrammistin-A is the first polyamine lactam to be
isolated from an animal, although similar compounds
with a pithecolobine-type skeleton have been isolated
from terrestrial plants.23 In contrast to spermine (1,5,-
10,14-tetraazatetradecane) alkaloids from terrestrial
plants, lipogrammistin-A has a 1,5,11,15-tetraazapenta-
decane moiety as a polyamine component, which is
presumably biosynthesized from cadaverine. Although
cadaverine and its derivatives are found throughout the
animal kingdom, no natural alkaloids have hitherto been
reported to have this uncommon polyamine unit.
F igu r e 1. 1H NMR of natural and synthetic lipogrammistin-A
and the difference spectra: (a) natural lipogrammistin-A and
synthetic 1a ; (b) natural lipogrammistin-A and synthetic 1b.
thesis of the 4R diastereomer of 1 was complete. Like-
wise, the 4S diastereomer 1b was synthesized via amide
18b.
Com p a r ison of th e Syn th etic Dia ster eom er s 1a
a n d 1b w ith Na tu r a l Lip ogr a m m istin -A. The two
diastereoisomers 1a and 1b were indistinguishable by
chromatography; the Rf value on silica gel TLC and the
retention time in reversed-phase HPLC for both diaster-
eomers were identical to those of the natural product.
Comparison of the specific optical rotations was not
successful because these two isomers showed quite
similar values and the amounts of synthetic samples
available were too small to detect their minute difference.
Thus, the diastereomers were compared with natural 1
using NMR spectroscopy.
To make the secondary amine in 1 completely ionized,
1% TFA-d was added to CD3OD. Under these conditions,
the spectrum of the 4S isomer 1b again agreed com-
pletely with that of the natural lipogrammistin-A, while
minute but distinct differences were observed between
the 4R isomer 1a and the natural product, as depicted
in the difference spectra (Figure 1). Thus, the absolute
configuration at the C4 position was determined to be S,
and elucidation of the entire structure and the total
synthesis of lipogrammistin-A (1) were accomplished
simultaneously.
Exp er im en ta l Section
Gen er a l Meth od s. NMR spectra were recorded at 500
1
1
MHz for H, 125 MHz for 13C or 400 MHz for H, 100 MHz for
13C at 300 K unless otherwise noted. 1H chemical shifts were
referenced on the basis of residual solvent peaks: CHCl3 (δ
7.24) in CDCl3, CD2HOD (δ 3.30) in CD3OD, or CR-H of
pyridine-d4 (δ 8.50) in pyridine-d5. 13C chemical shifts were
referenced with respect to the 13C signal of CDCl3 (δ 77.0), CD3-
OD (δ 49.0), or CR of pyridine-d5 (δ 149.8). Reactions requiring
anhydrous conditions were carried out under an atmosphere
of nitrogen or argon with dry, freshly distilled solvents.
Extr a ction a n d Isola tion of Lip ogr a m m istin -A fr om
A. tem m in cki. From the skin of one specimen of thawed fish
A. temmincki (17 cm length, 77.5 g weight), which was
collected off Izu Penninsula, J apan, the mucus was scraped
off with spatula (0.75 g wet weight) and suspended in acetone
(300 mL). The surface of the fish was washed well with
acetone (100 mL). The combined acetone extracts were filtered
and concentrated, and the resultant residue was partitioned
between EtOAc (200 mL) and H2O (200 mL). The aqueous
layer was extracted with EtOAc (200 mL × 3), the combined
organic layer was concentrated, and the crude residue (45.4
mg) was fractionated by silica gel flash column chromatogra-
Discu ssion
(23) For example: Mar, W.; Tan, G. T.; Cordell, G. A.; Pezzuto, J .
M.; J urcic, K.; Offermann, F.; Redl, K.; Steinke, B.; Wagner, H. J . Nat.
Prod. 1991, 54, 1531-1542.
It is noteworthy that lipogrammistin-A exists in solu-
tion as a conformational mixture of four different states,

Total Synthesis of Lipogrammistin-A
J . Org. Chem., Vol. 63, No. 12, 1998 3929
phy (3 g, CHCl3 to 16% MeOH-CHCl3 stepwise elution).
Dragendorff-positive fractions were combined (13.8 mg) and
subjected to reversed-phase HPLC (ODS, YMC AM-323, 10 ×
250 mm, CH3CN-H2O-TFA, 60:40:0.05, UV at 220 nm and
RI detections). The major peak was collected and further
purified by silica gel column chromatography (0.5 g, CHCl3 to
8% MeOH-CHCl3 stepwise elution) to afford 3.0 mg of
The catalyst was filtered off through Celite, and the filtrate
was concentrated. The residue was dissolved in EtOAc,
washed with 1 N aqueous HCl and then H2O, and dried over
MgSO4. Filtration and concentration gave a crude residue that
was chromatographed on silica gel (hexane-EtOAc) to afford
1.24 g (90%) of (+)-8 as a colorless oil: [R]25 +15.8 (c 1.01,
D
CHCl3); IR (film) 3376 cm-1; 1H NMR (500 MHz, CDCl3) δ 5.49
(m 1H), 5.34 (m, 1H), 3.87 (dd, 1H, J ) 13, 2 Hz), 3.56 (dd,
1H, J ) 13, 6 Hz), 2.95 (m, 1H), 2.37 (m, 1H), 1.99 (m, 2H),
1.35-1.19 (m, 10H), 0.84 (m, 3H, J ) 7 Hz); 13C NMR (125
MHz, CDCl3) δ 133.3, 122.7, 61.6, 58.1, 55.2, 31.6, 29.5, 29.4,
29.3, 29.3, 29.2, 27.3, 22.6, 14.0; MS (EI) m/z (rel intensity)
226 (30), 196 (39), 161 (62), 135 (68), 83 (100); HRMS (EI) m/z
calcd for C14H26O (M+) 226.1933, found 226.1960. By the same
procedure, 809 mg of (-)-8 was obtained from 1.12 g of (-)-7
lipogrammistin-A (0.4% yield based on wet mucus): [R]25
D
+13.8 (c 0.2, MeOH); other spectroscopic data were identical
to that of lipogrammistin-A isolated from D. bifasciatum.15
Acid Hyd r olysis of Lip ogr a m m istin -A a n d Deter m i-
n a tion of th e Ster eoch em istr y of 2-Meth ylbu tyr ic Acid .
A mixture of lipogrammistin-A (1.5 mg) and 3 N aqueous HCl
(1 mL) in a capped vial tube was heated at 110 °C for 5 h.
After cooling, the reaction mixture was extracted with Et2O
and CH2Cl2, and the combined organic layer was dried over
MS4A. To this, HOBt, DCC, and (S)-1-(1-naphthyl)ethylamine
were added (each 10 mg). After the mixture was stirred
overnight, filtration and concentration gave a residue, which
was purified by preparative TLC, followed by HPLC (SiO2,
YMC A-012, 6 × 150 mm, hexane-EtOAc, 5:1, UV detection
at 280 nm). Determination of the diastereomeric ratio was
performed by reversed-phase HPLC (ODS, Develosil HG-5, 4.6
× 150 mm, CH3CN-H2O, 40:60, 1 mL/min, UV detection at
280 nm): retention time, (S)-2-methyl-N-[(S)-1-(1-naphthyl)-
ethyl]butyramide in 27.4 min; (R)-2-methyl-N-[(S)-1-(1-naph-
thyl)ethyl]butyramide in 28.6 min. The ratio of S:R was 85:
15 as the peak area.
in 71% yield: [R]25 -16.9 (c 1.14, CHCl3).
D
(3R,5Z)- a n d (3S,5Z)-5-Tetr a d ecen e-1,3-d iol ((-)- a n d
(+)-9). To a solution of (+)-8 (1.34 g, 5.92 mmol) and dry THF
(50 mL) was added sodium bis(2-methoxyethoxy)aluminum
hydride (70% in toluene solution; 3.7 mL, 11.8 mmol) at 0 °C.
The mixture was stirred at 0 °C overnight. Saturated aqueous
NH4Cl was added, and the mixture was diluted with EtOAc.
The resulting insoluble material was filtered off, and the
filtrate was washed with brine and dried over MgSO4. Filtra-
tion and concentration gave a residue, which was chromato-
graphed on silica gel (hexane-EtOAc) to give 1.34 g (99%) of
diol (-)-9 as a colorless oil: [R]29D -4.5 (c 1.15, CHCl3); IR (film)
1
3381 cm-1; H NMR (500 MHz, CDCl3) δ 5.52 (m, 1H), 5.35
(E)-Tetr a d ec-2-en -5-yn -1-ol (6). To a solution of diyne 517
(65.0 mg, 0.315 mmol) in Et2O (10 mL) was added LiAlH4 in
Et2O (1 M solution, 0.35 mL, 0.35 mmol) at room temperature.
After the mixture was stirred for 2 h, 1 N HCl was added.
The organic layer was washed with 1 N HCl, water, and brine
and dried over Na2SO4. Filtration and concentration gave a
residue, which was chromatographed on silica gel (hexane-
AcOEt) to afford 42.7 mg (65%) of 6 as a colorless oil: IR (film)
(m, 1H), 3.83 (m, 1H), 3.82 (m, 1H), 3.77 (m, 1H), 2.22 (m,
2H), 2.01 (brtd, 2H, J ) 7, 7 Hz), 1.67 (m, 2H), 1.35-1.17 (m,
12H), 0.84 (t, 3H, J ) 7 Hz); 13C NMR (125 MHz, CDCl3) δ
133.7, 124.5, 71.8, 61.7, 37.7, 35.6, 31.6, 29.5, 29.4, 29.3, 29.2,
27.4, 22.6, 14.1; MS (EI) m/z (rel intensity) 228 (0.8), 210 (16),
154 (40), 75(100); HRMS (EI) m/z calcd for C14H26O (M - H2O)+
210.1984, found 210.2002. By the same procedure 342.1 mg
of (+)-9 was obtained from 369.9 mg of (-)-8 in 92% yield:
3342, 2215 cm-1; H NMR (500 MHz, CDCl3) δ 5.88 (dtt, 1H,
[R]29 +5.7 (c 0.93, CHCl3)
1
D
J ) 15, 6, 2 Hz), 5.67 (dtt, 1H, J ) 15, 5, 1 Hz), 4.10 (dd, 2H,
J ) 6, 1 Hz), 2.91 (m, 2H), 2.14 (m, 2H), 1.46 (tt, 2H, J ) 8, 8
Hz), 1.35-1.19 (m, 10H), 0.85 (t, 3H, J ) 7 Hz); 13C NMR (125
MHz, CDCl3) δ130.2, 127.4, 82.8, 76.5, 63.2, 31.8, 29.2, 29.1,
29.0, 28.9, 22.6, 21.7, 16.7, 14.1; MS (EI) m/z (rel intensity)
(3S,5Z)- a n d (3R,5Z)-3-Azid o-1-[(ter t-bu tyld ip h en ylsi-
lyl)oxy]-5-tetr a d ecen e ((+)- a n d (-)-10). To a solution of
diol (-)-9 (1.18 g, 5.20 mmol) and imidazole (0.96 g, 14.1 mmol)
in DMF (30 mL) was added TBDPSCl (1.3 mL, 5.72 mmol) at
0 °C. The mixture was stirred for 30 min at this temperature,
diluted with Et2O, washed with H2O and then saturated
aqueous NH4Cl, and dried over MgSO4. Filtration and con-
centration gave a crude silyl ether, which was dissolved in dry
CH2Cl2 (40 mL). To this solution were added Et3N (3.6 mL,
26 mmol) and MsCl (0.8 mL, 10.3 mmol) at 0 °C. After the
mixture was stirred at 0 °C for 1 h, saturated aqueous NH4Cl
was added. The organic layer was washed with saturated
aqueous NH4Cl, aqueous NaHCO3, and brine and dried over
MgSO4. Filtration and concentration gave the crude mesylate,
which was dissolved in DMF (40 mL). To this solution was
added NaN3 (90% purity, 1.7 g, 26 mmol). After being stirred
at 50 °C overnight, the reaction mixture was poured into Et2O,
washed with H2O, and dried over MgSO4. Filtration and
concentration gave a residue, which was chromatographed on
silica gel (hexane-Et2O) to yield 2.27 g (89%) of azide (+)-10
208 (48), 192 (100), 190 (59); HRMS (EI) m/z calcd for C14H22
O
(M+) 208.1827, found 208.1837.
(2S,3R)- a n d (2R,3S)-2,3-Ep oxytetr a d ec-5-yn -1-ol ((+)-
a n d (-)-7). A mixture of alcohol 6 (1.49 g, 7.15 mmol) and
MS4A in dry CH2Cl2 (50 mL) was cooled to -23 °C. To this
mixture were added (+)-DET (1.50 mL, 8.58 mmol) and Ti(O-
i-Pr)4 (2.2 mL, 7.15 mmol) successively. After the mixture was
stirred for 1 h, tert-butyl hydroperoxide (5.5 M in 2,2,4-
trimethylpentane solution, 2.60 mL, 14.3 mmol) was added.
The mixture was kept at -25 °C overnight. The reaction was
quenched by addition of EtOAc and saturated aqueous Na2-
SO4. After being stirred for 30 min, the mixture was filtered
through a Celite pad. Evaporation of the solvent gave a crude
residue, which was chromatographed on silica gel (hexane-
EtOAc) to afford 1.37 g (85%) of (+)-7 as a colorless solid: mp
55-56 °C; [R]28 +8.3 (c 1.24, CHCl3); IR (film) 3401, 2230
as a colorless oil: [R]26 +13.7 (c 1.39, CHCl3); IR (film) 2099
D
D
1
cm-1
;
1H NMR (500 MHz, CDCl3) δ 3.81 (dd, 1H, J ) 13, 2
cm-1; H NMR (500 MHz, CDCl3) δ 7.64 (m, 4H), 7.44-7.36
Hz), 3.63 (dd, 1H, J ) 13, 4 Hz), 3.09 (m, 2H), 2.58 (ddt, 1H,
J ) 18, 4, 2 Hz), 2.46 (ddt, 1H, J ) 18, 5, 2 Hz), 2.10 (tt, 2H,
J ) 7, 2 Hz), 1.44 (tt, 2H, 7, 7 Hz), 1.35-1.19 (m, 10H), 0.85
(t, 3H, J ) 7 Hz); 13C NMR (125 MHz, CDCl3) δ 82.9, 73.8,
61.2, 57.8, 53.6, 31.8, 29.1, 29.0, 28.8, 28.8, 22.6, 21.6, 18.7,
14.0; MS (EI) m/z (rel intensity) 244 (5), 182 (10), 134 (19), 92
(100); HRMS (EI) m/z calcd for C14H24O2 (M+) 224.1776, found
224.1751. By the same procedure using (-)-DET instead of
(+)-DET, 1.22 g of (-)-7 was obtained from 1.36 g of 6 in 83%
(m, 6H), 5.54 (m, 1H), 5.38 (m, 1H), 3.82-3.71 (m, 2H), 3.64
(m, 1H), 2.32 (m, 2H), 2.06 (brtd, 2H, J ) 7, 7 Hz), 1.77 (m,
1H), 1.62 (m, 1H), 1.39-1.20 (m, 12H), 1.03 (s, 9H), 0.86 (t,
3H, J ) 7 Hz); 13C NMR (125 MHz, CDCl3) δ 135.5, 135.5,
133.7, 133.5, 133.4, 129.7, 127.7, 124.3, 60.4, 59.5, 36.7, 32.4,
31.8, 29.5, 29.5, 29.3, 29.3, 27.5, 26.8, 22.7, 19.2 (3C), 14.1;
MS (EI) m/z (rel intensity) 434 (25), 406 (100), 391 (17); HRMS
(EI) m/z calcd for C30H45ONSi (M - N2)+ 463.3271, found
463.3228. By the same procedure, 963.0 mg of (-)-10 was
obtained in three steps from 574.6 mg of (+)-9 in 78% yield:
yield: [R]25 -8.5 (c 0.83, CHCl3).
D
(-)-(2S,3R,5Z)- a n d (+)-(2R,3S,5Z)-2,3-Ep oxy-5-tetr a d e-
cen -1-ol ((+)- a n d (-)-8). Lindlar catalyst (1 g) in MeOH
(30 mL) and quinoline (0.3 g) was hydrogenated until absorp-
tion of hydrogen ceased. To this mixture was added epoxide
(+)-7 (1.36 g, 6.06 mmol) in MeOH (10 mL), and the mixture
was then hydrogenated under hydrogen atmosphere overnight.
[R]25 -17.3 (c 1.16, CHCl3).
D
(3S,5Z)- a n d (3R,5Z)-1-[(ter t-Bu tyld ip h en ylsilyl)oxy]-
3-[(ter t-bu toxyca r bon yl)a m in o]-5-tetr a d ecen e ((+)- a n d
(-)-11). A solution of azide (+)-10 (2.27 g, 4.63 mmol) and
Ph3P (2.5 g, 9.2 mmol) in THF (40 mL) and H2O (0.9 mL) was
stirred at 45 °C overnight. Evaporation of the solvent gave a

3930 J . Org. Chem., Vol. 63, No. 12, 1998
Onuki et al.
crude residue, which was dissolved in EtOAc and dried over
Na2SO4. Filtration and concentration gave a crude amine,
which was dissolved in dry CH2Cl2 (50 mL). To this solution
were added Et3N (0.8 mL, 5.6 mmol) and Boc2O (1.5 mL, 6.9
mmol), and the mixture was stirred at room temperature
overnight. Evaporation of the solvent gave a residue, which
was chromatographed on silica gel (hexane-Et2O) to afford
The mixture was stirred at room temperature for 10 min and
concentrated. A resulting crude methyl ester was dissolved
in CH2Cl2 (2 mL), and to this solution was added TFA (1 mL).
Stirring for 20 min and concentration gave a crude residue,
which was dissolved in EtOAc (5 mL) and neutralized with
saturated aqueous NaHCO3 (2 mL). The organic layer was
dried by passing through a Na2SO4 column (0.5 × 3 cm), and
the eluent was concentrated. A crude residue was dissolved
in CH2Cl2 (1 mL), and to this solution were added (R)-
MTPAOH (8 mg) and DCC (15 mg). The mixture was stirred
at room temperature for 30 min and purified directly by
preparative TLC (hexane-EtOAc 2:1) to give 13a as an (R)-
MTPA amide. In the same way, 13b was prepared from (+)-
3. J udging from the 1H NMR spectra of 13a and 13b , the
optical purity of (-)-3 was 95% ee, and that of (+)-3 was 95%
ee: 1H NMR (500 MHz, CDCl3) 13a δ 5.46 (m, 1H), 5.23 (m,
2.50 g (96%) of (+)-11 as a colorless oil: [R]25 +12.8 (c 1.17,
D
CHCl3); IR (film) 1716 cm-1; 1H NMR (500 MHz, CDCl3) δ 7.65
(m, 4H), 7.43-7.34 (m, 6H), 5.45 (m, 1H), 5.30 (m, 1H), 5.05
(br, 1H), 3.75 (br, 2H), 3.68 (brm, 1H), 2.26 (br, 2H), 1.97 (brtd,
2H, J ) 7, 7 Hz), 1.78 (br, 1H), 1.56 (br, 1H), 1.40 (s, 9H),
1.34-1.17 (m, 12H), 1.04 (s, 9H), 0.86 (t, 3H, J ) 7 Hz); 13C
NMR (125 MHz, CDCl3) δ 155.4, 135.6, 133.4, 132.6, 129.9,
127.7, 125.0, 78.8, 61.5, 49.1, 35.7, 32.4, 31.9, 29.7, 29.5, 29.3,
29.3, 28.4 (3C), 27.4, 26.8, 22.7, 19.1 (3C), 14.1; MS (EI) m/z
(rel intensity) 565 (0.1), 492 (7.3), 452 (100), 412 (16), 356 (38),
330 (49), 254 (16), 234 (20), 224 (19), 199 (19), 176 (10), 57
(22); HRMS (EI) m/z calcd for C35H55NO3Si (M+) 565.3951,
found 565.3996. By the same procedure, 811.7 mg of (-)-11
5
1H), 4.31 (m, 1H), 3.66 (s, 3H), 3.39 (d, 3H, J HF ) 1 Hz), 2.58
(d, 2H, J ) 5.5 Hz), 2.31 (brt, 2H, J ) 7 Hz), 1.91 (m, 2H),
1.35-1.20 (m, 12H), 0.86 (t, 3H, J ) 7 Hz); 13b δ 5.53 (m,
5
1H), 5.30 (m, 1H), 4.28 (m, 1H), 3.58 (s, 3H), 3.38 (d, 3H, J HF
was obtained from 963.0 mg of (-)-10 in 73% yield: [R]23
-13.4 (c 0.90, CHCl3)
D
) 1 Hz), 2.54 (d, 2H, J ) 5.5 Hz), 2.37 (brt, 2H, J ) 7 Hz),
1.98 (m, 2H), 1.35-1.20 (m, 12H), 0.86 (t, 3H, J ) 7 Hz).
(+)-(3S,5Z)- a n d (-)-(3R,5Z)-3-[(ter t-Bu toxyca r bon y-
l)a m in o]-5-tetr a d ecen -1-ol ((+)- a n d (-)-12). A mixture of
(+)-11 (96.1 mg, 0.170 mmol), dry THF (3 mL), and tetrabu-
tylammonium fluoride (1 M in THF solution; 0.28 mL, 0.28
mmol) was stirred at room temperature for 3 h. Concentration
and chromatography of the crude residue on silica gel (hex-
ane-Et2O) gave 53.9 mg (97%) of (+)-12 as a colorless oil:
[R]26D +17.1 (c 1.37, CHCl3); IR (film) 3300, 1699 cm-1; 1H NMR
(500 MHz, CDCl3) δ 5.50 (brm, 1H), 5.32 (brm, 1H), 4.46 (brd,
1H), 3.81 (br, 1H), 3.61 (brm, 2H), 3.50-3.30 (br, 1H), 2.28
(m, 1H), 2.15 (m, 1H), 1.99 (brtd, 2H, J ) 7, 7 Hz), 1.80 (m,
1H), 1.41 (s, 9H), 1.36-1.18 (m, 12H), 0.85 (3H, t, J ) 7 Hz);
13C NMR (125 MHz, CDCl3) δ 157.0, 133.4, 124.4, 79.7, 58.9,
47.1, 38.2, 32.8, 31.9, 29.6, 29.5, 29.3, 29.2, 28.3, 27.4, 22.6,
14.1; MS (EI) m/z (rel intensity) 327 (0.1), 272 (2.7), 254 (12),
174 (28), 118 (52), 74 (34), 57 (100), 41(36); HRMS (EI) m/z
calcd for C19H37NO3 (M+) 327.2774, found 327.2790. By the
same procedure, 135.1 mg of (-)-12 was obtained from 237.9
N-(Cya n oeth yl)-1,5-d ia m in op en ta n e (15). Acrylonitrile
(0.377 mL, 5.13 mmol) was added dropwise to a solution of
1,5-diaminopentane (14) (0.500 mL, 4.27 mmol) in MeOH (10
mL) at room temperature. The resulting mixture was allowed
to stand at room temperature for 2 h. Concentration and flash
chromatography on silica gel (CHCl3-MeOH-i-PrNH2) gave
287 mg (43%) of 15 as a colorless oil: IR (film) 3354, 2247
cm-1 1H NMR (CDCl3, 400 MHz) δ 2.61 (t, 2H, J ) 7 Hz),
;
2.40 (brt, 2H, J ) 7 Hz), 2.34 (t, 2H, J ) 7 Hz), 2.24 (t, 2H, J
) 7 Hz), 1.21 (tt, 2H, J ) 7, 7 Hz), 1.19 (t, 2H, J ) 7 Hz), 1.09
(m, 2H); 13C NMR (CDCl3, 100 MHz) 118.3, 48.2, 44.3, 32.2,
28.9, 24.0, 23.6, 17.8; MS (EI) m/z (rel intensity) 155 (51), 138
(34), 128 (25), 115 (40), 109 (86), 86 (64), 56 (95), 42 (100), 30
(97); HRMS (EI) m/z calcd for C8H17N3 (M+) 155.1423, found
155.1439.
Eth yl 12-Cya n o-4,10-d ia za d od eca n oa te (16). To a solu-
tion of 15 (2.76 g, 17.8 mmol) in EtOH (50 mL) was added
ethyl acrylate (2.32 mL, 21.3 mmol) dropwise at room tem-
perature. Stirring was continued at room temperature for 24
h. Evaporation of the solvent left an oil, which was subjected
to flash column chromatography on silica gel (CHCl3-i-PrNH2)
to give 2.22 g (49%) of 16 as an oil: IR (film) 3319, 2247, 1730
mg of (-)-11 in 98% yield: [R]27 -15.7 (c 0.99, CHCl3).
D
(3S,5Z)- a n d (3R,5Z)-3-[(ter t-Bu toxyca r bon yl)a m in o]-
5-tetr a d ecen oic Acid ((+)- a n d (-)-3). To a solution of
oxalyl chloride (1.35 mL, 17.3 mmol) and dry DMSO (2.12 mL)
in dry CH2Cl2 (60 mL) at -78 °C was added (+)-12 (1.41 g,
4.32 mmol) in CH2Cl2 (5 mL) and the mixture stirred for 20
min. After addition of Et3N (12.5 mL), the mixture was stirred
for 1 h at 0 °C, and then satuated aqueous NH4Cl was added.
The organic layer was washed with satuated aqueous NH4Cl
and satuated aqueous NaHCO3 and then dried over Na2SO4.
Filtration and concentration gave a residue, which was dis-
solved in 2-methyl-2-propanol (40 mL) and H2O (16 mL). To
this solution were added 2-methyl-2-butene (1.12 mL, 19.4
mmol), NaH2PO4‚2H2O (382 mg, 4.75 mmol), and NaClO2 (86%
purity, 1.22 g, 14.3 mmol). After the mixture was stirred for
30 min, 5% aqueous KHSO4 (3 mL) was added. The mixture
was extracted with CH2Cl2, and the organic layer was dried
over MgSO4, filtered, and concentrated. Chromatography of
the residue on silica gel (CHCl3) gave 1.32 g (90%) of (+)-3 as
a colorless oil, which solidified upon standing: mp 53-55 °C;
cm-1 1H NMR (CDCl3, 500 MHz) δ 3.84 (q, 2H, J ) 7 Hz),
;
2.63 (t, 2H, J ) 7 Hz), 2.58 (t, 2H, J ) 7 Hz), 2.37-2.31 (m,
4H), 2.25 (t, 2H, J ) 7 Hz), 2.22 (t, 2H, J ) 7 Hz), 1.21 (t, 2H,
J ) 7 Hz), 1.22 (m, 4H), 1.09 (m, 2H), 0.97 (t, 3H, J ) 7 Hz);
13C NMR (CDCl3, 125 MHz) 172.4, 116.7, 60.0, 49.0, 48.8, 44.9,
44.8, 34.5, 29.6, 29.6, 24.6, 18.4, 14.0; HRMS (EI) m/z calcd
for C13H25N3O2 (M+) 255.1947, found 255.1935.
Eth yl 12-Cya n o-4,10-bis((2S)-2-m eth ylbu tyr yl)-4,10-d i-
a za d od eca n oa te (17). To a stirred solution of 16 (2.22 g,
8.71 mmol), DMF (50 mL), (S)-2-methylbutyric acid (2.09 mL,
19.2 mmol), and HOBt (3.33 g, 21.8 mmol) was added WSCI
(4.17 mg, 21.8 mmol). The mixture was stirred overnight at
room temperature. The solvent was evaporated in vacuo, and
the residue was dissolved in EtOAc and washed successively
with 5% aqueous KHSO4, aqueous NaHCO3, and brine. The
organic layer was dried over Na2SO4. Filtration and concen-
tration gave a residue, which was purified by flash column
chromatography on silica gel (CHCl3-MeOH) to give 3.02 g
[R]27 +10.2 (c 0.76, MeOH); IR (film) 3500-3000 (br), 1714,
D
1699 cm-1; H NMR (500 MHz, CDCl3) δ 5.51 (m, 1H), 5.32
1
(m, 1H), 3.96 (br, 1H), 2.53 (br, 2H), 2.30 (brm, 2H), 2.01 (brtd,
2H, J ) 7, 7 Hz), 1.41 (s, 9H), 1.37-1.17 (m, 12H), 0.86 (3H,
t, J ) 7 Hz); 13C NMR (125 MHz, CDCl3) δ 176.5, 155.5, 133.6,
124.3, 79.5, 47.6, 38.7, 32.1, 31.9, 29.6, 29.5, 29.3, 29.3, 28.4
(3C), 27.4, 22.6, 14.1; MS (EI) m/z (rel intensity) 341 (0.7), 285
(2), 268 (8), 224 (12), 188 (35), 132 (53), 88 (75), 57 (100); HRMS
(EI) m/z calcd for C19H35NO4 (M+) 341.2566, found 341.2574.
By the same procedure 93.1 mg of (-)-3 was obtained from
(82%) of diamide 17 as a colorless oil: [R]25 +27.7 (c 1.23,
D
CHCl3); IR (film) 2249, 1730, 1643 cm-1; 1H NMR (CDCl3, 500
MHz) δ 4.09 and 3.99 (q each, 2H, J ) 7 Hz), 3.45 (m, 2H),
3.40 (m, 2H), 3.35-3.13 (m, 4H), 2.58 (m, 2H), 2.54-2.36 (m,
2H), 1.63-1.40 (m, 6H), 1.30 (m, 2H), 1.20 (m, 2H), 1.15 and
1.12 (t each, 3H, J ) 7 Hz), 0.97 (m, 6H), 0.74 (m, 6H); 13C
NMR (CDCl3, 125 MHz) 177.1, 177.0, 176.5, 176.5, 172.1,
170.9, 118.4, 118.3, 118.3, 60.8, 60.4, 49.1, 49.1, 49.1, 48.4, 45.4,
43.2, 43.2, 43.1, 43.0, 42.7, 37.3, 37.2, 37.1, 34.5, 32.9, 29.6,
29.5, 29.5, 29.3, 27.3, 27.3, 27.3, 27.2, 23.9, 23.9, 17.7, 17.7,
17.6, 17.6, 16.2, 16.2, 16.1, 14.1, 14.1, 11.9, 11.9; MS (EI) m/z
(rel intensity) 423 (M+, 23), 378 (14), 366 (17), 338 (100), 292
116.2 mg of (-)-12 in 77% yield: [R]27 -13.8 (c 0.91, MeOH).
D
Deter m in a tion of th e Op tica l P u r ity a n d Absolu te
Ster eoch em istr y of (+)- a n d (-)-3. To a solution of car-
boxylic acid (-)-3 (3 mg) in PhH-MeOH (3:1, 3 mL) was added
(trimethylsilyl)diazomethane (10% in hexane solution, 1 mL).

Total Synthesis of Lipogrammistin-A
J . Org. Chem., Vol. 63, No. 12, 1998 3931
(19), 184 (12), 168 (17), 137 (18), 130 (44), 85 (19), 57 (69);
HRMS (EI) m/z calcd for C23H41N3O4 (M+) 423.3097, found
423.3079.
9H), 1.33-1.20 (m, 12H), 1.08 (m, 6H), 0.85 (m, 9H); MS (FAB,
m-nitrobenzyl alcohol) m/z 707 (M + H)+, 607 (M - Boc + H)+.
(4R)-Lip ogr a m m istin -A (1a ). A solution of aldehyde 19a
(29.2 mg, 0.0413 mmol) in dry CH2Cl2 (3 mL) and TFA (1 mL)
was stirred at room temperature for 20 min. Concentration
gave a residue that was dissolved in dry MeOH (120 mL). To
this solution were added MS3A (10 g) and Et3N to adjust the
pH of the solution to 7. After the solution was stirred at room
temperature overnight, NaBH3CN (26 mg, 0.41 mmol) was
added. The mixture was stirred at room temperature for 72
h and filtered through a Celite pad, followed by addition of
water. The mixture was extracted with EtOAc, and the extract
was dried over Na2SO4. Concentration and chromatography
on alumina (neutral, activity II, 2 g, CHCl3) gave a crude
residue, which was further purified by HPLC (ODS, YMC AM-
323, 10 × 250 mm, CH3CN-H2O-TFA 60:40:0.05) to afford
Eth yl 4,10-Bis((2S)-2-m eth ylbu tyr yl)-4,10,14-tr ia za tet-
r a d eca n oa te (4). To a solution of 17 (3.02 g, 7.14 mmol) in
EtOH (80 mL) and CHCl3 (1.6 mL) was added platinum(IV)
oxide (200 mg). The mixture was stirred under hydrogen
atmosphere overnight at room temperature. The catalyst was
filtered off through a Celite pad. The filtrate was neutralized
with i-PrNH2 and evaporated to give a crude residue that was
chromatographed on silica gel (CHCl3-MeOH-i-PrNH2) to
afford 2.25 g (74%) of 4 as a colorless oil: [R]25 +23.3 (c 1.29,
D
CHCl3); IR (film) 3461, 3288, 1734, 1633 cm-1
;
1H NMR
(CDCl3, 500 MHz) δ 4.14-4.05 (m, 2H), 3.62-3.41 (m, 2H),
3.45-3.12 (m, 6H), 2.74-2.59 (m, 2H), 2.58-2.43 (m, 4H), 1.65
(m, 4H), 1.54 (m, 4H), 1.36 (m, 2H), 1.30-1.18 (m, 5H), 1.15
(m, 6H), 0.84 (m, 6H); 13C NMR (CDCl3, 125 MHz) 176.8, 176.7,
176.5, 176.5, 176.4, 172.2, 172.2, 170.9, 60.9, 60.8, 60.5, 60.4,
48.6, 48.5, 47.4, 47.3, 45.8, 45.6, 45.5, 45.4, 43.2, 43.1, 42.8,
42.6, 39.4, 39.3, 38.9, 37.3, 37.2, 37.2, 37.1, 37.1, 34.5, 34.5,
33.3, 32.9, 29.6, 29.5, 29.4, 29.3, 27.5, 27.4, 27.4, 27.3, 24.2,
24.1, 17.9, 17.9, 17.8, 17.8, 17.7, 17.7, 14.1, 14.1, 12.0, 12.0,
12.0, 11.9, 11.9; MS (EI) m/z (rel intensity) 427 (33), 382 (12),
370 (32), 342 (67), 325 (33), 313 (100), 299 (81), 270 (16), 213
(17), 186 (23), 184 (37), 130 (26), 112 (17), 98 (42), 57 (83);
HRMS (EI) m/z calcd for C23H45N3O4 (M+) 427.3410, found
427.3386.
5.7 mg (23%) of 1a : [R]30 +18 (c 0.06, MeOH); 1H NMR (500
D
MHz, CD3OD containing 1% TFA-d) δ 5.69 (m, 1H), 5.34 (m,
1H), 3.66-3.25 (m, 8H), 3.20-3.08 (m, 3H), 2.81-2.64 and
2.56-2.41 (m, each 4H), 2.09 (brdd, 2H, J ) 7, 7 Hz), 2.07-
1.60 (m, 10H), 1.50-1.23 (m, 16H), 1.09 (m, 6H), 0.90 (t, 3H,
J ) 7 Hz), 0.89 (m, 6H); MS (EI) data were identical to those
of lipogrammistin-A.
E t h yl 14-[(3S,5Z)-3-[(ter t-Bu t oxyca r b on yl)a m in o]-5-
tetr a d ecen yl]-4,10-bis((2S)-2-m eth ylbu tyr yl)-4,10,14-tr i-
a za tetr a d eca n oa te (18b). To a mixture of carboxylic acid
(+)-3 (132.2 mg, 0.388 mmol) and HOBt (90.0 mg, 0.589 mmol)
in dry CH2Cl2 (5 mL) were added successively amine 4 (211.5
mg, 0.495 mmol) in dry CH2Cl2 (8 mL) and WSCI (111.5 mg,
0.582 mmol). After being stirred at room temperature over-
night, the mixture was diluted with EtOAc and washed with
5% aqueous KHSO4, saturated aqueous NaHCO3, and brine.
The organic layer was dried over Na2SO4. Filtration and
concentration gave a residue, which was chromatographed on
silica gel (CHCl3-MeOH) to afford (256.4 mg, 88%) of 18b as
E t h yl 14-[(3R,5Z)-3-[(ter t-Bu t oxyca r b on yl)a m in o]-5-
tetr a d ecen yl]-4,10-bis((2S)-2-m eth ylbu tyr yl)-4,10,14-tr i-
a za tetr a d eca n oa te (18a ). To a solution of carboxylic acid
(-)-3 (38.6 mg, 0.113 mmol) in dry CH2Cl2 (2 mL) were added
successively HOBt (35.0 mg, 0.226 mmol), amine 4 (72.5 mg,
0.170 mmol) in dry CH2Cl2 (2 mL) and WSCI (43.4 mg, 0.226
mmol). After being stirred at room temperature overnight,
the mixture was diluted with EtOAc and washed with 5%
aqueous KHSO4, saturated aqueous NaHCO3, and brine. The
organic layer was dried over Na2SO4. Filtration and concen-
tration gave a residue, which was chromatographed on silica
gel (CHCl3-MeOH) to afford (51.9 mg, 61%) of 18a as a
colorless oil: [R]27D +10.9 (c 2.77, CHCl3); IR (film) 3309, 1733,
a colorless oil: [R]25 +17.7 (c 0.59, CHCl3); IR (film) 3307,
D
1734, 1711, 1643, 1637 cm-1 1H NMR (CDCl3, 500 MHz) δ
;
7.07 (brt), 7.00 (brt), 6.88 (m), and 6.79 (m) (1H for four
signals), 5.45 (m, 1H), 5.27 (m, 1H), 4.13 and 4.09 (each q,
2H, J ) 7 Hz), 3.89 (brm, 1H), 3.60 and 3.51 (m, 2H), 3.45-
3.15 (m, 6H), 3.10 (m, 2H), 2.60-2.45 (m, 4H), 2.38 (br, 2H),
2.28 (brt, 2H), 1.97 (m, 2H), 1.70-1.50 (m, 8H), 1.39 (s, 9H),
1.39 (m, 2H), 1.33-1.26 (m, 17H), 1.07 (m, 6H), 0.85 (m, 9H);
MS (FAB, m-nitrobenzyl alcohol) m/z 751 (M + H)+, 651 (M -
Boc + H)+.
1708, 1645, 1637, 1630 cm-1 1H NMR (CDCl3, 500 MHz) δ
;
7.07 (brt), 7.00 (brt), 6.88 (m), and 6.79 (m) (1H for four
signals), 5.45 (m, 1H), 5.27 (m, 1H), 4.13 and 4.09 (each q,
2H, J ) 7 Hz), 3.89 (brm, 1H), 3.60 and 3.51 (m, 2H), 3.45-
3.15 (m, 6H), 3.10 (m, 2H), 2.60-2.45 (m, 4H), 2.38 (br, 2H),
2.28 (brt, 1H), 1.97 (m, 2H), 1.70-1.50 (m, 8H), 1.39 (s, 9H),
1.39 (m, 2H), 1.33-1.26 (m, 17H), 1.07 (m, 6H), 0.85 (m, 9H);
MS (FAB, m-nitrobenzyl alcohol) m/z 751 (M + H)+, 651 (M -
Boc + H)+.
14-[(3S,5Z)-3-[(ter t-Bu toxyca r bon yl)a m in o]-5-tetr a d e-
cen yl]-4,10-b is((2S)-2-m et h ylb u t yr yl)-4,10,14-t r ia za t et -
r a d eca n a l (19b). To a solution of 18b (131.8 mg, 0.176 mmol)
in THF (5 mL) and MeOH (14 µL) was added LiBH4 (8 mg,
0.38 mmol) at 0 °C. The mixture was stirred at 0 °C for 30
min and then at room temperature overnight. Additional
LiBH4 (8 mg, 0.38 mmol) was added, and the mixture was
stirred at room temperature overnight. The reaction was
quenched with 1 M aqueous potassium sodium tartarate (2
mL). The mixture was stirred for 1 h at 0 °C and extracted
with CHCl3. The combined organic layer was washed with
brine, dried over Na2SO4, and concentrated to afford a crude
residue, which was subjected to flash chromatography on silica
gel (CHCl3-MeOH) to afford 120.8 mg (97%) of the alcohol. A
part of this alcohol (99.9 mg, 0.141 mmol) was dissolved in
dry CH2Cl2 (2 mL) and DMSO (1 mL). To this solution were
added Et3N (138 µL, 0.99 mmol) and SO3-pyridine complex
(89.8 mg, 0.56 mmol) at 0 °C. After the mixture was stirred
for 2 h at 0 °C and then at room temperature for 1 h, EtOAc
(30 mL) was added. Washing with H2O, 5% aqueous KHSO4,
saturated aqueous NaHCO3, and brine, drying over Na2SO4,
and concentration gave a crude residue, which was subjected
to flash chromatography on silica gel (CHCl3-MeOH) to afford
14-[(3R,5Z)-3-[(ter t-Bu toxyca r bon yl)a m in o]-5-tetr a d e-
cen yl]-4,10-b is((2S)-2-m et h ylb u t yr yl)-4,10,14-t r ia za t et -
r a d eca n a l (19a ). To a solution of 18a (49.5 mg, 0.070 mmol)
in dry THF (3 mL) and MeOH (10 µL) was added LiBH4 (8
mg, 0.37 mmol). After the mixture was stirred at 0 °C for 20
min and at room temperature overnight, 1 M aqueous potas-
sium sodium tartarate was added. The mixture was stirred
at 0 °C for 1 h and extracted with CHCl3. The combined
organic layer was washed with brine and dried over Na2SO4.
Filtration and concentration gave a residue, which was
subjected to flash chromatography on silica gel (CHCl3-
MeOH) to afford 39.4 mg (84%) of the alcohol as a colorless
oil. To a solution of this alcohol (39.4 mg, 0.056 mmol) in dry
CH2Cl2 (2 mL) and DMSO (1 mL) were added Et3N (55 µL,
0.39 mmol) and SO3-pyridine complex (35.4 mg, 0.22 mmol)
at 0 °C. After the mixture was stirred at 0 °C for 2 h and at
room temperature for 1 h, EtOAc (20 mL) was added. Washing
with H2O, 5% aqueous KHSO4, and brine, drying over Na2-
SO4, and concentration gave a crude residue, which was
chromatographed on silica gel (CHCl3-MeOH) to afford 33.8
74.0 mg (74%) of 19b as an oil: [R]22 +24.3 (c 1.48, MeOH);
mg (86%) of aldehyde 19a as an oil: [R]22 +11.7 (c 0.35,
D
D
IR (film) 3313, 1705, 1701, 1697, 1624 cm-1; 1H NMR (CDCl3,
500 MHz) δ 9.82 and 9.75 (m, 1H), 7.1-6.9 (brm, 1H), 5.46
(m, 1H), 5.33 (m, 1H), 3.87 (m, 1H), 3.65-3.53 (brm, 2H), 3.40-
3.11 (m, 8H), 2.76 and 2.72 (m, 2H), 2.56-2.27 (m, 6H), 1.98
(m, 2H), 1.70-1.50 (m, 8H), 1.40 (m, 2H), 1.39 (brs, 9H), 1.33-
MeOH); IR (film) 3313, 3302, 1708, 1699, 1633, 1626 cm-1; 1H
NMR (CDCl3, 500 MHz) δ 9.82 and 9.75 (m, 1H), 7.1-6.9 (brm,
1H), 5.46 (m, 1H), 5.33 (m, 1H), 3.87 (m, 1H), 3.65-3.53 (brm,
2H), 3.40-3.11 (m, 8H), 2.76 and 2.72 (m, 2H), 2.56-2.27 (m,
6H), 1.98 (m, 2H), 1.70-1.50 (m, 8H), 1.40 (m, 2H), 1.39 (brs,

3932 J . Org. Chem., Vol. 63, No. 12, 1998
Onuki et al.
1.20 (m, 12H), 1.08 (m, 6H), 0.85 (m, 9H); MS (FAB, m-
nitrobenzyl alcohol) m/z 707 (M + H)+, 607 (M - Boc + H)+.
J ) 7 Hz), 0.89 (m, 6H); MS (EI) data were identical to those
of lipogrammistin-A.
(4S)-Lip ogr a m m istin -A (1b). A solution of aldehyde 19b
(56.8 mg, 0.083 mmol) in dry CH2Cl2 (3 mL) and TFA (1 mL)
was stirred at room temperature for 20 min. Concentration
gave a residue that was dissolved in dry MeOH (100 mL). To
this solution were added MS3A (5 g) and Et3N to adjust the
pH of the solution to 7. After the solution was stirred at room
temperature overnight, NaBH3CN (50 mg, 0.80 mmol) was
added. The mixture was stirred at room temperature for 72
h and filtered through a Celite pad, followed by addition of
water. The mixture was extracted with EtOAc and the extract
was dried over Na2SO4. Concentration and chromatography
on alumina (neutral, activity II, 2 g, CHCl3) gave a crude
residue, which was further purified by HPLC (ODS, YMC AM-
Ack n ow led gm en t. The authors are grateful to Dr.
Hiroshi Hirota, Exploratory Research for Advanced
Technology (ERATO), J apan Science and Technology
Corporation (J ST), for his assistance with the measure-
ment of NMR spectra and to Professor Michio Murata
in our laboratory for his valuable comments and critical
reading of this manuscript.
Su p p or tin g In for m a tion Ava ila ble: 1H spectra of natu-
ral lipogrammistin-A, 1a ,b, 3, 4, 6-12, 15-17, 18a ,b, and
19a ,b; 13C NMR spectra of 3, 4, 6-12, 15-17, and natural
lipogrammistin-A at 300 and 333 K; mass spectra of natural
lipogrammistin-A and 1a ,b (31 pages). This material is
contained in libraries on microfiche, immediately follows this
article in the microfilm version of the journal, and can be
ordered from the ACS; see any current masthead page for
ordering information.
323, 10 × 250 mm, CH3CN-H2O-TFA, 60:40:0.05) to afford
1
3.4 mg (7%) of 1b: [R]30 +11 (c 0.03, MeOH); H NMR (500
D
MHz, CD3OD containing 1% TFA-d) δ 5.69 (m, 1H), 5.34 (m,
1H), 3.55-3.25 (m, 8H), 3.23-3.04 (m, 3H), 2.81-2.64 and
2.56-2.41 (m, each 4H), 2.09 (brdd, 2H, J ) 7, 7 Hz), 2.07-
1.60 (m, 10H), 1.50-1.23 (m, 16H), 1.09 (m, 6H), 0.90 (t, 3H,
J O9722461