4,5,6-Trisubstituted piperidinones as conformationally restricted ceramide analogues: Synthesis and evaluation as inhibitors of sphingosine and ceramide kinases and as NKT cell-stimulatory antigens

Article abstract of DOI:10.1002/cbdv.200900045

The conformationally based piperidinone sphingosine analogues 7, 8, 15, and 16 were synthesized from allylic alcohol 34 via lactams 31 and 32. The L-arabino diol 7 and the L-ribo diol 8 were transformed into the amino alcohols 17-24. The L-gluco ceramide

Full text of DOI:10.1002/cbdv.200900045

1688
CHEMISTRY & BIODIVERSITY – Vol. 6 (2009)
4,5,6-Trisubstituted Piperidinones as Conformationally Restricted Ceramide
Analogues: Synthesis and Evaluation as Inhibitors of Sphingosine and
Ceramide Kinases and as NKT Cell-Stimulatory Antigens1)
by Thresen Mathewa), Marco Cavallarib), Andreas Billichc), Frederic Bornancinc), Peter
Nussbaumerc), Gennaro De Liberob), and Andrea Vasella*a)
a) Laboratorium fꢀr Organische Chemie, Departement Chemie und Angewandte Biowissenschaften,
ETH Zꢀrich, Wolfgang-Pauli-Strasse 10, CH-8093 Zꢀrich
(e-mail: vasella@org.chem.ethz.ch)
b) Department of Biomedicine, University Hospital Basel, CH-4031 Basel
c) Novartis Institutes for BioMedical Research, Brunner Strasse 59, A-1235 Vienna
The conformationally based piperidinone sphingosine analogues 7, 8, 15, and 16 were synthesized
from allylic alcohol 34 via lactams 31 and 32. The l-arabino diol 7 and the l-ribo diol 8 were transformed
into the amino alcohols 17–24. The l-gluco ceramide analogues 43, 46a, and 47, and the l-altro ceramide
analogues 51a and 52 were synthesized from either 31 or 32. The l-ribo diols 8 and 16, and the amino
alcohols 19 and 20 inhibit sphingosine kinase 1 (SPHK1), while the l-arabino analogues 7, 15, 17, and 18
are inactive. The l-arabino and the l-ribo dimethylamines 21–24, the l-gluco ceramide analogues 43,
46a, and 47, and the l-altro ceramide analogues 51a and 52 did not block SPHK1. Neither the l-arabino
diol 7 nor the l-ribo diol 8 inhibited SPHK2 or ceramide kinase. The l-arabino diols 7 and 15 stimulate
invariant natural killer T (iNKT) cells when presented by living antigen-presenting cells (APC) and also
by plate-bound human CD1d, whereas the l-ribo diols 8 and 16, the l-arabino amino alcohols 17–18, and
the dimethylamines 21–22 did not activate iNKT cells. The l-gluco ceramide analogues 43, 46a, and 47
had strongly stimulatory effects on iNKT cells when presented by living APC and also by plate-bound
human CD1d, whereas the l-altro ceramide analogue 52 activated only weakly. All activatory
compounds induced preferentially the release of pro-inflammatory cytokines, indicating the formation of
a stable CD1dꢀlipidꢀT-cell receptor complex.
Introduction. – (Glyco)sphingolipids and more specifically ceramides (Cers) adopt
a parallel orientation of the lipid chains in the cell membrane, requiring a (Z)-
configuration of the amide moiety, while the (E)-configuration of amides is preferred
in solution and in the solid state by a free-energy difference of ca. 1.2 kcal/mol [1][2].
There is no a priori reason why the amide moiety of a Cer complexed to a receptor
should either adopt the (E)- or the (Z)-configuration. The crystal structure of a-
galactosylceramide (aGalCer) bound to the human and the mouse CD1d receptor
shows the (E)-configuration, i.e., the two alkyl chains diverge from each other [3],
suggesting that the configuration of the amide moiety, and not only its H-bond acceptor
and donor properties, may be crucial for the interaction with receptors. Yet, only very
few compounds have been prepared that may be considered conformationally well-
defined ceramide analogues and are biologically active. The isoquinolines 1 were
1
)
Taken in part from the projected Ph.D. Theses of T. M. (chemical part) and M. C. (biological part).
ꢁ 2009 Verlag Helvetica Chimica Acta AG, Zꢀrich

CHEMISTRY & BIODIVERSITY – Vol. 6 (2009)
1689
investigated as conformationally restricted analogues of Cer, and act as ligands of
protein phosphatase 2A, a Cer-binding protein that has been implicated in signal
transmission [4]. The uracil and thiouracil derivatives 2a and 2b, respectively, are
further examples which exhibit moderate antitumour activity and toxicity in vitro and
in vivo [5]. Finally, the analogues 3 and 4 [6] inhibit GM-2 synthase. In 2006, Jang et al.
isolated from the marine fungus Acremonium sp. AWA16–1 awajanomycin (5) and its
derivative 6, a piperidinone-based cytotoxic agent [7]. Both 5 and 6 inhibit the growth
of A549 cells with IC50 values of 27.5 and 46.4 mg/ml, respectively.
We were interested in restricting the conformation of the head group of Cer, and in
particular of the amide moiety, as they are recognized and modified by sphingosine
(Sph)- and Cer-metabolizing enzymes. The conformationally restricted l-arabino and
the l-ribo piperidinones2) 7 and 8, respectively, may be considered analogues of Sph,
and the l-gluco, l-manno, l-altro, and l-allo piperidinones 9–12, respectively, may be
considered Cer analogues mimicking the (Z)-configuration of the amide. The
piperidinones 9–12, substituted at C(3) and C(6), possess most of the structural
features that are required for the biological functions of ceramides, viz., OH groups at
C(1) and C(3) [3], the N-acylamino substituent at C(2), an (E)-C¼C bond in the lipid
chain of the sphingosine moiety [3][8], and a substituent at C(3) corresponding to the
lipid part of the N-acyl substituent. As compared to Sphs and Cers, the piperidinones
possess one or two additional stereogenic centers, resulting in four diastereoisomeric
pairs of enantiomers of the Sph analogues 7 and 8, and in eight diastereoisomeric pairs
of enantiomers of the Cer analogues 9–12. Two and four diastereoisomers possess the
same configuration at the corresponding centres as d-erythro-sphingosine (13) and
ceramide (14), respectively. Starting the synthesis from d-galactose will result in these
two and four diastereoisomers 7–12.
2
)
Piperidinones are also known as hexonolactams. The configuration is specified by the carbohydrate
prefix in the Theoretical Part, and by the (R/S)-designation in the Exper. Part.

1690
CHEMISTRY & BIODIVERSITY – Vol. 6 (2009)
Biological properties for which the piperidinone analogues should be tested include
the inhibition of sphingosine [9] and ceramide kinases [10], and the effect on the
production of lymphokines [11].
We intended to first synthesize the trisubstituted piperidinones 7 and 8, their
dihydro analogues 15 and 16, and the unsaturated and saturated amines 17–24, and to
then introduce the alkyl chain at C(3) via an enolate anion [12][13].
Synthesis. – We planned to prepare the piperidinones 7 and 8 from the known
d-galactose-derived azide 25 [14], the Eschenmoser–Claisen rearrangement [15]
appearing the most promising method for the introduction of the acetamido side chain

CHEMISTRY & BIODIVERSITY – Vol. 6 (2009)
1691
(Schemes 1 and 2). As the N3 group interfered with the Claisen rearrangement, we
reduced 25 to the amine 26 that was protected by (tert-butoxy)carbonylation to 27
(Scheme 1). Desilylation gave the allylic alcohol 28 that is thus available from d-
galactose via d-galactal in nine steps and in a ca. 50% overall yield [14]. The
diastereoisomeric lactams 30 were obtained via Eschenmoser–Claisen rearrangement
of 28 that led to a 2 :1 mixture of the diastereoisomeric amides 29 (85%). Treating a
solution of 29 first with CF3CO2H in CH2Cl2 and then 1m HCl in THF cleaved the N-
Boc group and effected lactamisation to a 3 :1 mixture of the l-arabino-configured 30a
and the l-ribo-epimer 30b. Olefin metathesis [16] of 30a/30b 3 :1 with undec-1-ene
catalyzed by Grubbꢂs second-generation catalyst [16] yielded 70% exclusively of a
3 :1 mixture of the (E)-alkenyl-substituted pyrimidinones 31 and 32.
Scheme 1
a) Me3P, THF/H2O 4 :1. b) Boc2O, b-cyclodextrin, H2O/acetone/MeOH 4 :1:1. c) Bu4NF (TBAF)·
3 H2O, THF; 90% from 25. d) MeC(OMe)2NMe2, o-xylene, 1458; 85%. e) 1. CF3CO2H, CH2Cl2; 2. 1m
HCl, THF, reflux; 85%. f) Dodec-1-ene, [(RuCl2(CHPh)(PCy3)2], CH2Cl2; 70% of 31/32 3 :1.
We also introduced the lipid chain before the Eschenmoser–Claisen rearrange-
ment, adding C11H23MgBr to the unsaturated aldehyde 33 that was obtained by
oxidation of 28 with Dess–Martinꢂs reagent (Scheme 2). Eschenmoser–Claisen
rearrangement of the resulting 11:9 mixture of allylic alcohols 34 led to a 1:1 mixture
of the (E)-alkenyl amides 35 (74% from 28). No (Z)-isomers were detected. This
sequence proved advantageous on account of an easier purification of the products 31
and 32. The N-Boc group of 35 was cleaved, and the resulting amines were transformed
into the lactams 31 and 32 (85%), as described above for the transformation of 29 to 30.
A 1:1 mixture of 31 and 32 was debenzylated by treatment with AlCl3 in the presence
of anisole to yield 75% of a ca. 1:1 mixture 7/8. The isomers were separated by
crystallisation (MeOH/Et2O) and/or column chromatography on Lichoprep CN silica
gel.

1692
CHEMISTRY & BIODIVERSITY – Vol. 6 (2009)
Scheme 2
a) Dess–Martinꢂs periodinane, CH2Cl2; 95%. b) C11H23MgBr, Et2O; 86%. c) MeC(OMe)2NMe2,
o-xylene, 1458; 90%. d) 1. CF3CO2H, CH2Cl2; 2. 1m HCl, THF, reflux; 85%. e) AlCl3, anisole, CH2Cl2;
40% of 7 and 35% of 8. f) 10% Pd/C, 6 bar of H2, AcOH, MeOH; 47% of 15 and 40% of 16.
The structure of the piperidinones 7 and 8 is evidenced by 1H-NMR spectroscopy,
and established by X-ray crystal-structure analysis (Fig. 1,a)3). Suitable crystals of
both isomers were obtained from MeOH/Et2O.
The crystal structure of 7 shows a 4H5 half-chair conformation with all substituents
in a pseudoequatorial orientation (Fig. 1,b). The epimer 8 adopts a 5H4 conformation
with a pseudoequatorial alkenyl substituent and pseudoaxial CH2OH and OH groups.
4
5
5
A priori, one might expect 8 to adopt H5 and H4 conformations, while the H4
conformation is adopted in the solid state and preferred in solution, as evidenced by
J(4,5)¼3.3 and J(5,6)¼4.8 Hz. The preference for this conformation is attributed to
3
)
The crystallographic data have been deposited with the Cambridge Crystallographic Data Centre as
deposition No. CCDC-720463 for 7, 720464 for 8, and 720465 for 15. Copies of the data can be
obtained free of charge via http://www.ccdc.cam.ac.uk/data_request/cif (or from the Cambridge
Crystallographic Data Centre, 12 Union Road, Cambridge CB2 1EZ (fax: þ44(1223)336033; e-mail:
deposit@ccdc.cam.ac.uk).

CHEMISTRY & BIODIVERSITY – Vol. 6 (2009)
1693
Fig. 1. a) Crystal structures (ORTEP diagrams) of 7, 8, and 15. b) Half-chair conformations of 7 and 8.
the favourable gauche-effect involving the C(2)ꢀN and C(3)ꢀO bonds that overcomes
the destabilisation resulting from the pseudoaxial orientation of the CH2OH and OH
groups, while it does not overcome the combined preference of these substituents for a
pseudoequatorial orientation, as realized for 7, and evidenced, in solution, by J(4,5)¼
10.2 and J(5,6)¼9.3 Hz.
For many years, dihydroceramides were regarded as biologically inert [17]. Recent
studies [18–21] indicate, however, that these lipids are biologically active, with
activities differing from those of Cer. We, therefore, prepared 15 and 16, the dihydro
analogues of 7 and 8, by catalytic hydrogenation of 31 and 32, respectively (Scheme 2).
The structure of 15 is confirmed by X-ray-analysis (Fig. 1,a).
We also synthesised the amines 17–20 and the N,N-dimethylamines 21–24
(Scheme 3), since analogues possessing a basic amino group are expected to be
phosphorylated faster by Sph or Cer kinases, and may also inhibit these enzymes.
To introduce the amino group, we subjected the l-arabino diol 7 to a Mitsunobu
reaction with HN3 (Scheme 3). Unfortunately, it proved very difficult to separate the
resulting azide 36 from Ph3PO. A partial purification succeeded when we substituted
Ph3P by [4-(dimethylamino)phenyl](diphenyl)phosphine [22], as most of the resulting

1694
CHEMISTRY & BIODIVERSITY – Vol. 6 (2009)
Scheme 3
a) [4-(Dimethylamino)phenyl](diphenyl)phosphine, diethyl azodicarboxylate, HN3 in toluene, THF;
80%. b) 1. Me3P, THF; 2. 1m NaOH; 90% of 17; 60% of 19. c) 10% Pd/C, 8 bar of H2, AcOEt; 95% of 18;
80% of 20; 97% of 22; 94% of 24. d) TsCl, iPr2NEt, 4-(dimethylamino)pyridine (DMAP), CH2Cl2; 82%
of 37; 88% of 39. e) NaN3, DMF, 1008; 50%. f) Me2NH, THF/H2O, 858; 95% of 21; 92% of 23.
oxide was removed by acidic workup. Staudinger reduction [23] of 36 yielded the l-
arabino amino alcohol 17, and catalytic hydrogenation gave the dihydro analogue 18.
The analogous procedure failed to provide the NH2 analogue of the l-ribo diol 8, while
tosylation of the primary OH group of 8, followed by nucleophilic substitution by
NaN3, provided the azido derivative 38. Catalytic hydrogenation of 38 yielded 80% of
the dihydro l-ribo amino alcohol 20, while Staudinger reduction of the N3 group
yielded 60% of the l-ribo amino alcohol 19. The dimethylamino derivatives 21 and 23
were obtained by tosylating 7 to 39 and, similarly, 8 to 37, followed by substitution with
HNMe2 to give 21 and 23 in yields of 95 and 92%, respectively. Catalytic hydrogenation
of 21 afforded 22 (97%); similarly, 23 gave 24 (94%).

CHEMISTRY & BIODIVERSITY – Vol. 6 (2009)
1695
The alkyl chains at C(3) were introduced after N-(tert-butoxy)carbonylating 31 and
32 to 40 and 48 (80–83% yield), respectively (Scheme 4). The N-(tert-butoxy)carbo-
nylated l-arabino lactam 40 was deprotonated with LiHMDS at ꢀ788 in the presence
of a small amount of HMPA [12][13], and the resulting enolate anion was treated with
excess allyl bromide to yield 70% of the l-gluco lactam 42 as a single diastereoisomer.
It was debocylated and then hydrogenated to yield 68% of the saturated l-gluco
ceramide analogue 43. The l-arabino lactam 40 was also alkenylated with excess (E)-1-
bromobut-2-ene to yield 63% of a 3 :1 mixture of the tetrasubstituted l-gluco and l-
manno piperidinones 44a and 44b, respectively. Similarly, the enolate anion derived
from 48 was alkenylated with (E)-1-bromobut-2-ene to provide 60% of an inseparable
3 :1 mixture of the l-altro and l-allo diastereoisomers 49a and 49b, respectively.
Alkenylation in the absence of HMPA resulted in lower yields (< 30%). Removal of
the Boc groups in 44a/44b to 45a/45b, followed by debenzylation yielded 67% of a
3 :1 mixture of the l-gluco and l-manno piperidinones 46a and 46b, respectively.
Similarly, 49a/49b was transformed via 50a/50b into a 3 :1 mixture of the l-altro and l-
allo isomers 51a and 51b, respectively, in 61% yield. Palladium-catalyzed hydro-
genation of the 3 :1 mixtures 45a/45b and 50a/50b in MeOH/AcOH yielded the
saturated l-gluco piperidinone 47 and the l-altro isomer 52, respectively, in 74–75%
yield as single diastereoisomers. We assume that the Pd-catalyzed migration of the
C¼C bond, followed by hydrogenation, resulted in the thermodynamically favoured
isomer.
The lactam ring of the N-unprotected l-arabino- and l-gluco-configured piper-
idinones 7, 15, 17, 18, 30a, 31, 36, 39, 42, 43, 45a, 46a, and 47 adopts a 4H5 conformation
(see Fig. 1,b) with pseudoequatorial substituents evidenced by large J(3ax,4),
J(3eq,4), J(4,5), and J(5,6) values (ꢁ 8.7 Hz; Table 1). This conformation is
disfavoured for the N-Boc derivatives 40, 41, and 44 by the allylic 1,3-strain (see [24]
and refs. cit. therein) between the Boc and the BnOCH2 group; a B3,6 conformation is
evidenced by small J(5,6) (2.1–2.7 Hz) and large J(3ax,4), J(3,4), and J(4,5) values
(ꢁ 8.1 Hz). The N-Boc l-ribo- and l-altro-configured piperidinones 48 and 49a adopt a
5H4 conformation (see Fig. 1,b) with pseudoequatorial alkenyl and pseudoaxial BnO
and BnOCH2 substituents, evidenced by small J(4,5)¼J(5,6)¼2.4 Hz and a large
J(3ax,4)¼11.6 Hz. The N-unprotected l-ribo- and l-altro-configured 8, 16, 23, 24, 30b,
32, 37, 50a, 51a, and 52 (J(3ax,4)¼J(3,4)¼6.4–8.9, J(4,5)¼2.3–3.9, J(5,6)¼2.9–
5
8.1 Hz) prefer an equilibrium between H4 and 4H5 and/or boat conformations.
Biological Results. – 1. Sph and Cer Kinase Inhibition. The l-ribo diol 8 inhibited
sphingosine kinase 1 (SPHK1) [25] with an IC50 value of 11.6 mm and 93% inhibition at
the highest test concentration of 100 mm, while the l-arabino diol 7 showed only
marginal inhibition (14%) at 100 mm, demonstrating the specificity of the enzyme. It is
remarkable that the l-arabino diol 7 has a conformation similar to that of a sphingoid
base, but it is not a good inhibitor for SPHK1; in contradistinction, the l-ribo diol 8 with
a biased gauche-conformation about the C(2)ꢀC(3) bond, as favoured by the gauche-
effect, is a better inhibitor (Fig. 1,b), suggesting that a similar conformation of a
sphingoid base is relevant for the binding to SPHK1. Such a conformation may be
favoured by protonating Sph leading to a stronger gauche-effect. Neither the l-arabino
7 nor the l-ribo-configured diols 8 inhibited SPHK2 or Cer kinase [26] at

1696
CHEMISTRY & BIODIVERSITY – Vol. 6 (2009)
Scheme 4
a) Boc2O, DMAP, MeCN; 80% of 40; 83% of 48. b) 1m Lithium hexamethyldisilazide (LiHMDS) in
toluene, then hexamethylphosphoric triamide (HMPA) and allyl bromide, THF; 70%. c) CF3CO2H,
anisole, THF; 85% of 42; 86% of 45a/45b; 80% of 50a/50b. d) 10% Pd/C, 8 bar of H2, AcOH, MeOH;
80% of 43; 75% of 47; 74% of 52. e) 1m LiHMDS in toluene, then HMPA and (E)-1-bromobut-2-ene,
THF; 63% of 44a/44b 3 :1; 60% of 49a/49b 3 :1. f) AlCl3, anisole, 1,2-dichloroethane; 78% of 46a/46b
3 :1; 76% of 51a/51b 3 :1.

CHEMISTRY & BIODIVERSITY – Vol. 6 (2009)
1697
1
Table 1. Selected H-NMR Coupling Constants [Hz] of the Piperidinones in CDCl3 or CD3OD Listed
According to Their Configuration
Compound
7
15
17
18
21
22
30a
31
36
39
40
l-arabino
a
a
J(3ax,4)
J(3eq,4)
J(4,5)
11.7
5.1
11.7
11.8
5.3
10.1
8.8
11.8
4.9
9.9
9.9
)
)
)
)
)
)
)
)
11.3
5.4
11.2
5.2
10.8
5.1
11.1
5.4
9.6
9.0
12.4
5.2
9.1
2.6
a
a
4.8
10.7
9.0
a
a
a
a
a
10.2
9.3
)
)
)
a
a
a
a
a
J(5,6)
)
)
)
Compound
8
16
19
20
23
24
30b
32
37
38
48
l-ribo
8.7
5.7
3.3
4.8
a
a
a
a
a
a
a
J(3ax,4)
J(3eq,4)
J(4,5)
)
)
)
)
)
)
)
)
)
)
)
)
)
)
6.6
5.4
6.5
5.4
3.3
6.2
)
)
)
)
)
)
11.6
5.2
2.4
2.4
a
a
a
a
a
a
a
a
a
a
a
2.3
2.9
3.9
8.1
3.6
7.4
)
3.6
3.6
a
a
a
a
J(5,6)
)
Compound
41
44a
42
43
45a
46a
47
49a
50a
51a
52
l-gluco
9.3
8.1
l-altro
)
2.4
2.4
a
a
a
J(3,4)
J(4,5)
J(5,6)
)
9.9
9.9
8.7
9.5
9.5
8.7
9.6
9.6
9.0
10.2
10.2
9.2
9.0
10.2
8.8
)
8.9
2.6
3.8
6.4
3.2
6.0
8.5
2.7
3.1
5.3
2.1
a) Not assigned.
concentrations of up to 100 mm; thus, l-ribo 8 is a specific inhibitor of SPHK1 among
the lipid kinases tested here. In keeping with these results, the dihydro derivative 16 of
l-ribo 8 inhibited SPHK1 with an IC50 value of 9.8 mm, while the dihydro derivative 15
of l-arabino 7 did not inhibit the enzyme. Replacing the HOCH2 group of the l-ribo
diol 8 and 16 by an NH2CH2 group, as in the l-ribo amino alcohols 19 and 20, yielded
stronger inhibitors with IC50 values of 2.2 and 0.58 mm, respectively, while the l-arabino
17 and 18, and the l-arabino- as well as the l-ribo-configured dimethylamines 21–24
were inactive. The ceramide analogues 43, 46a, 47, 51a, and 52, resulting from the
introduction of an alkyl moiety at C(3) of the diols 7, 8, 15, and 16 did not block SPHK1.
2. Activation of Invariant Natural Killer T (iNKT) Cells. iNKT Cells recognize a
variety of lipid antigens presented by the CD1d molecule. Therefore, we tested whether
piperidinones are capable of stimulating this population of human T lymphocytes. The
piperidinones were first tested for cytotoxic effects in vitro. T Cells were incubated
overnight with increasing doses of the sonicated piperidinones, and the next day cell
death was assessed by measuring the uptake of propidium iodide or 7-aminoactino-
mycin D using a CYANTM ADP flow cytometer (Beckman Coulter, Fullerton,
California, USA). The median lethal concentrations (LC50) were calculated for each
compound (Table 2).
The piperidinones listed in Table 2, with the exception of l-altro 51a, were used to
stimulate human iNKT cells presented by THP1 cells transfected with human CD1d
gene (THP1-hCD1d; Fig. 2). In parallel experiments, plate-bound recombinant soluble
human CD1d was loaded with the relevant lipids and used to stimulate iNKT cells.
Briefly, THP1-hCD1d cells (2.5ꢂ104/well) or soluble plate-bound recombinant human
CD1d (5 mg/ml) were incubated with the sonicated compounds at the indicated

1698
CHEMISTRY & BIODIVERSITY – Vol. 6 (2009)
Table 2. Median Lethal Concentrations (LC50) of Piperidinones
Compound
Configuration
LC50 [mg/ml]
Compound
Configuration
LC50 [mg/ml]
7
15
17
18
21
22
43
46a
47
l-arabino
l-arabino
l-arabino
l-arabino
l-arabino
l-arabino
l-gluco
8
9
9
4.5
8
8
8
16
19
20
23
24
51a
52
l-ribo
l-ribo
l-ribo
l-ribo
l-ribo
l-ribo
l-altro
l-altro
n.d.a)
n.d.
4.5
4
9.5
n.d.
n.d.
7
>20
>20
>20
l-gluco
l-gluco
a) n.d.: Not determined.
Fig. 2. Piperidinones with a single lipid tail activate iNKT cells with living antigen-presenting cells (APC).
The l-arabino diols 7 and 15 stimulate iNKT cells when presented by THP1-hCD1d APC as measured by
!
!
*
*
release of human a) IL-4, b) IFN-g, and c) TNF-a ( ¼7, ¼8, ¼15, ¼16). d) Diols 7 and 15
preferentially induced a TH1 response, as visualized by the IFN-g /IL-4 ratio of the stereotype TH1 vs. TH2
cytokines IFN-g and by the TNF-a/IL-4 ratio.
concentrations in the presence of T cells (7.5ꢂ104/well or 1.5ꢂ105/well, resp.) at 378.
For competition assays, a fixed dose of the piperidinones was given 4.5 h in advance of

CHEMISTRY & BIODIVERSITY – Vol. 6 (2009)
1699
titrating aGalCer and addition of T cells. Culture supernatants were collected after
24 h, and iNKT cell released cytokines were measured by ELISA [27][28]. The l-
arabino diols 7 and 15 activated iNKT cells (Fig. 2), although they possess only one
lipid tail. This finding was unexpected, since all the iNKT cell-stimulatory compounds
so far described in the literature possess two lipid chains. To confirm that the T cell-
stimulatory activity is due to formation of complexes with CD1d and not to cellular
modifications induced by these piperidinones in APC, T cell-activation was tested using
CD1d plate-bound assays. Both l-arabino diols 7 and 15 were active also in this type of
assay (Fig. 3), thus confirming that they form stimulatory complexes with CD1d.
Fig. 3. Piperidinones with a single lipid tail activate iNKT cells when presented by plate-bound human
CD1d. The l-arabino configured diols 7 and 15 induce cytokine production by iNKT cells when
presented on recombinant soluble plate-bound human CD1d, as measured by released human IL-4.
The formation of complexes with CD1d is also supported by the finding that only
the l-arabino diols 7 and 15 possess stimulatory capacity, whereas the l-ribo diols 8 and
16 do not (Fig. 2).
Importantly, iNKT cells are activated by the l-arabino diol 7, but not by the l-
arabino amino alcohol 17 and the dimethylamino alcohol 21, with 7 differing from 17
and 21 only by the HOCH2 group at C(6). A similar activity was observed for the l-
arabino diol 15 that is active, whereas the l-arabino amines 18 and 22 are not. It is
tempting to speculate that the primary OH group is important in interacting,
presumably via H-bonding, with the CD1d molecule, thus determining its position
within CD1d. This OH group might also make binding contacts with the TCR of iNKT
cells, thus stabilizing the CD1dꢀlipidꢀTCR trimolecular complex, as shown for the
aGalCer antigen [29–31].
A second important finding is that only the l-arabino diols 7 and 15 were active,
whereas the l-ribo diols 8 and 16 were not, suggesting that binding of the lipid to CD1d,
or its positioning within CD1d, is dictated also by this structural element.

1700
CHEMISTRY & BIODIVERSITY – Vol. 6 (2009)
Since the presence of a second lipid tail in the lipid antigen might stabilize the
CD1dꢀlipid stimulatory complexes and facilitate T-cell activation, we tested piperi-
dinones with an additional substituent at C(3).
The l-gluco ceramide analogues 43, 46a, 47 had a strongly stimulatory effect on
iNKT cells when presented by living APC and also by plate-bound human CD1d,
whereas the l-altro ceramide analogue 52 activated only weakly (Fig. 4), suggesting
that, also in these compounds, the configuration at C(3) and C(4) is important. A
similar stimulatory activity was observed in plate-bound assays (Fig. 5), confirming
that each molecule forms stimulatory complexes with CD1d. The compounds with two
lipid tails showed a similar efficacy and potency as 7 and 15, which have only one lipid
tail, indicating that addition of a short alkenyl chain at C(3) does not change this
biological activity.
Fig. 4. Piperidinones with two lipid tails activate iNKT cells with living APC. The l-gluco ceramide
analogues 43, 46a, and 47, and the l-altro ceramide analogue 52 presented by THP1-hCD1d promote
~
~
~
release of human a) IL-4, b) IFN-g, and c) TNF-a by iNKT cells ($¼aGalCer, ¼43, ¼46a, ¼47,
*
¼52). d) All active compounds induced more of a TH1 response, as seen by the ratios IFN-g and
TNF-a to IL-4.
A final unexpected finding was that all tested compounds preferentially induce
release of TH1-like cytokines IFN-g and TNF-a, whereas the TH2 cytokine IL-4 is
released in low amounts. Fig. 2,d and Fig. 4,d show the IFN-g/IL-4 and TNF-a/IL-4

CHEMISTRY & BIODIVERSITY – Vol. 6 (2009)
1701
Fig. 5. Piperidinones with two lipid tails on plate-bound human CD1d activate iNKT cells. The l-gluco
ceramide analogues 43, 46a, and 47, and the l-altro-configured ceramide analogue 52 are stimulatory for
iNKT cells when presented on dimerized plate-bound human CD1d, as human IL-4 (a) and GM-CSF (b)
are released.
ratios with aGalCer, the l-arabino diols 7 and 15, the l-gluco ceramide analogues 43,
46a, and 47, and the l-altro ceramide analogue 52, respectively.
Thus, these piperidinones induce preferentially a TH1 response. As the tested iNKT
cells release both classes of cytokines when the aGalCer agonist is used as antigen, the
TH1-biased response has to be ascribed to the type of CD1dꢀlipid complexes formed
by these piperidinones. TH1 Responses have been associated with strong TCR
engagement, whereas TH2 responses have been ascribed to weak interactions. It is,
therefore, tempting to speculate that piperidinones form complexes with CD1d that
make high affinity interactions with the TCR of iNKT cells. Future studies will address
this point.
In conclusion, fine-tuning the structure of piperidinones may lead to the rational
design of new iNKT activatory compounds with unique biological properties. The
generation of lipid compounds preferentially inducing TH1 responses might have
applications in novel vaccination and antitumour therapies.
We thank Novartis AG, Basel, for a fellowship, the Swiss National Science Foundation and ETH
Zꢀrich for financial support, Dr. Bruno Bernet for numerous contributions to the manuscript, and Dr. W.
Bernd Schweizer for the X-ray analyses.
Experimental Part
General. See [14].
(E)-2-Amino-1,3-di-O-benzyl-6-O-[(tert-butyl)diphenylsilyl]-2,4,5-trideoxy-d-erythro-hex-4-enitol
(26). An ice-cold soln. of 25 [14] (2.18 g, 3.68 mmol) in THF (30 ml) was treated dropwise with 1m Me3P
in THF (7.4 ml, 7.4 mmol), stirred at 08 for 1 h and at 258 for 5 h, treated with H2O (7.5 ml), and stirred
for 24 h. After evaporation, a soln. of the residue in AcOEt (100 ml) was washed with H2O (100 ml). The
aq. phase was extracted with AcOEt (3ꢂ100 ml). The combined org. phases were washed with brine,

1702
CHEMISTRY & BIODIVERSITY – Vol. 6 (2009)
dried (Na2SO4), and evaporated to afford crude 26 (2.1 g, quant.) that was used directly for the next step.
A pure sample of 26 was obtained by FC (CH2Cl2/MeOH 9 :1). Colourless oil. [a]2D5 ¼ ꢀ22.6 (c¼0.5,
CHCl3). IR (ATR): 3383w, 3070w, 3029w, 2930w, 2856w, 1471w, 1454w, 1427w, 1380w, 1361w, 1260w,
1205w, 1110s, 1071m, 1028w, 975w, 822m, 738s, 699s, 633w. 1H-NMR (CDCl3, 300 MHz): 7.73–7.68 (m, 4
arom. H); 7.48–7.27 (m, 16 arom. H); 5.86 (dt, J ¼ 15.6, 4.5, HꢀC(5)); 5.72 (ddt, J¼15.9, 8.1, 1.5,
HꢀC(4)); 4.58 (d, J¼11.7, PhCH); 4.55 (d, J¼12.0, PhCH); 4.49 (d, J¼12.0, PhCH); 4.32 (d, J¼11.4,
PhCH); 4.30 (br. dd, J¼4.2, 1.2, 2 HꢀC(6)); 3.83 (dd, J¼7.8, 6.6, HꢀC(3)); 3.63 (dd, J¼9.3, 4.2,
HaꢀC(1)); 3.52 (dd, J¼9.0, 6.9, HbꢀC(1)); 3.10 (td, J¼6.6, 4.2, HꢀC(2)); 1.51 (br. s, NH2); 1.10 (s, t-Bu).
13C-NMR (CDCl3, 75 MHz): 138.40, 138.28 (2s); 135.42 (d, 4 CH); 134.82 (d, C(4)); 133.50 (s, 2 C);
129.67 (d, C(5)); 129.67–127.24 (several d); 80.99 (d, C(3)); 73.2 (t, PhCH2); 71.79 (t, PhCH2); 70.21 (t,
C(1)); 63.62 (t, C(6)); 54.37 (d, C(2)); 26.76 (q, Me3C); 19.18 (s, Me3C). HR-MALDI-MS: 566.3082 (100,
[M þ H]þ , C36H44NO3Siþ ; calc. 566.3090). Anal. calc. for C36H43NO3Si (565.83): C 76.42, H 7.66, N 2.48;
found: C 76.25, H 7.58, N 2.54.
(E)-1,3-Di-O-benzyl-6-O-[(tert-butyl)diphenylsilyl]-{[(tert-butoxy)carbonyl]amino}-2,4,5-trideoxy-
d-erythro-hex-4-enitol (27). A soln. of b-cyclodextrin (180.7 mg, 0.16 mmol) in H2O (40 ml) was treated
with a soln. of crude 26 (2.05 g, 3.63 mmol) in acetone/MeOH 1:1 (15 ml), followed by a soln. of Boc2O
(870.6 mg, 3.99 mmol) in acetone/MeOH 1:1 (5 ml), stirred at 258 for 45 min, diluted with H2O, and
extracted with CH2Cl2 (3ꢂ100 ml). The combined org. phases were washed with brine, dried (Na2SO4),
and evaporated to afford crude 27 (2.14 g, quant.) that was used directly for the next step. A small
amount was subjected to FC (AcOEt/hexane 1:4) to afford pure 27. Colourless oil. Rf (AcOEt/hexane
1:1) 0.84. [a]2D5 ¼ ꢀ22.2 (c¼0.75, CHCl3). IR (ATR): 3450w, 2961w, 2930w, 2857w, 1714m, 1496m, 1472w,
1454w, 1427w, 1390w, 1364w, 1275w, 1259w, 1167m, 1105s, 1063m, 1027m, 970w, 909w, 861w, 822w, 746s,
697s, 612w. 1H-NMR (CDCl3, 300 MHz): 7.71–7.69 (m, 4 arom. H); 7.47–7.28 (m, 16 arom. H); 5.85 (dt,
J ¼ 15.3, 4.2, HꢀC(5)); 5.73 (dd, J¼15.3, 7.2, HꢀC(4)); 4.88 (d, J¼9.0, NH); 4.58 (d, J¼12.0, PhCH);
4.52 (d, J¼12.0, PhCH); 4.45 (d, J¼12.0, PhCH); 4.32 (d, J¼11.4, PhCH); 4.25 (br. d, J¼3.6,
2 HꢀC(6)); 4.01 (t, J¼6.6, HꢀC(3)); 3.97–3.87 (br. s, HꢀC(2)); 3.78 (dd, J¼9.6, 4.5, HaꢀC(1)); 3.56
(dd, J¼9.3, 3.9, HbꢀC(1)); 1.42 (s, t-Bu); 1.10 (s, Me3CSi). 13C-NMR (CDCl3, 75 MHz): 155.35 (s, C¼O);
138.30, 138.15 (2s); 135.44 (d, 4 CH); 134.22 (d, C(4)); 133.57 (s, 2 C); 129.63 (d, C(5)); 129.63–127.28
(several d); 79.19 (d, C(3)); 79.19 (s, Me3CO); 73.14 (t, PhCH2); 70.52 (t, PhCH2); 68.85 (t, C(1)); 63.91 (t,
C(6)); 53.36 (d, C(2)); 28.51 (q, Me3CO); 26.76 (q, Me3CSi); 19.18 (s, Me3CSi). HR-MALDI-MS:
688.3430 (100, [M þ Na]þ , C41H51NNaO5Siþ ; calc. 688.3434). Anal. calc. for C41H51NO5Si (665.94):
C 73.95, H 7.72, N 2.10; found: C 73.46, H 8.01, N 2.12.
(E)-1,3-Di-O-benzyl-2-N-{[(tert-butoxy)carbonyl]amino}-2,4,5-trideoxy-d-erythro-hex-4-enitol
(28). An ice-cold soln. of crude 27 (2.125 g, 3.19 mmol) in THF (50 ml) was treated with Bu4NF (TBAF)·
3 H2O (2.04 g, 6.38 mmol), and stirred at 08 for 10 min and then at 258 for 13 h. The mixture was diluted
with AcOEt (100 ml), H2O (100 ml), and brine (5 ml). After separation of the layers, the aq. phase was
extracted with AcOEt (3ꢂ100 ml). The combined org. phases were washed with brine, dried (Na2SO4),
and evaporated to afford crude 28 that was filtered through a short pad of silica gel (AcOEt/pentane
1:4!1:1) to afford 28 (1.23 g, 90% from 25). Pale yellow oil. Rf (AcOEt/hexane 1:1) 0.51. [a]2D5 ¼ ꢀ35.6
(c¼1.3, CHCl3). IR (ATR): 3441w (br.), 3346w, 3030w, 2976w, 2929w, 2866w, 1694s, 1497s, 1453m, 1391w,
1
1365s, 1247w, 1204w, 1165m, 1091s, 1065s, 1026s, 974m, 911w, 860w, 778w, 735s, 697s. H-NMR (CDCl3,
300 MHz): 7.34–7.27 (m, 10 arom. H); 5.89 (dt, J ¼ 15.9, 5.4, HꢀC(5)); 5.70 (dd, J¼15.9, 7.8, HꢀC(4));
5.02 (d, J¼8.7, NH); 4.60 (d, J¼12.0, PhCH); 4.51 (d, J¼11.7, PhCH); 4.44 (d, J¼12.0, PhCH); 4.34 (d,
J¼11.7, PhCH); 4.19–4.08 (m, 2 HꢀC(6)); 3.96 (t, J¼7.5, HꢀC(3)); 3.91–3.78 (m, HaꢀC(1), HꢀC(2));
3.55 (dd, J¼8.7, 3.0, HbꢀC(1)); 2.36 (br. s, OH); 1.42 (s, t-Bu). 13C-NMR (CDCl3, 75 MHz): 155.53 (s,
C¼O); 138.20, 138.01 (2s); 134.02 (d, C(4)); 128.87 (d, C(5)); 128.28–127.47 (several d); 79.23 (s, Me3C);
79.03 (d, C(3)); 73.07 (t, PhCH2); 70.54 (t, PhCH2); 68.59 (t, C(1)); 62.54 (t, C(6)); 53.23 (d, C(2)); 28.29
(q, Me3C). HR-MALDI-MS: 450.2255 (100, [M þ Na]þ , C25H33NNaO5þ ; calc. 450.2256). Anal. calc. for
C25H33NO5 ·0.3 H2O (432.9378): C 69.31, H 7.82, N 3.24; found: C 69.31, H 8.03, N 3.24.
4,6-Di-O-benzyl-5-{[(tert-butoxy)carbonyl]amino}-2,3,5-trideoxy-N,N-dimethyl-3-C-vinyl-l-arabi-
no- and -l-ribo-hexonamide (29). A soln. of 28 (120 mg, 0.28 mmol) in o-xylene (3 ml) was treated with
N,N-dimethylacetamide dimethyl acetal (0.1 ml, 0.56 mmol), stirred at 1458 for 5 h, cooled to 258, diluted
with AcOEt (50 ml), and washed with H2O (50 ml). The aq. phase was extracted with AcOEt (3ꢂ

CHEMISTRY & BIODIVERSITY – Vol. 6 (2009)
1703
50 ml). The combined org. phases were washed with brine, dried (Na2SO4), and evaporated. FC (AcOEt/
pentane 3 :7!1:1) gave 29 (2 :1 mixture of diastereoisomers; 118 mg, 85%). Colourless gum. Rf
(AcOEt/hexane 2 :3) 0.43. 1H-NMR (CDCl3, 300 MHz, 2 :1 mixture of diastereoisomers): 7.38–7.22
(m, 10 arom. H); 5.90 (br. dt, J¼17.5, 9.5, 0.33 H), 5.87 (br. dt, J¼17.5, 9.5, 0.67 H) (HꢀC(1’)); 5.13–5.05
(m, 2 HꢀC(2’)); 4.95 (d, J¼9.0, NH); 4.66–4.52 (m, 2 PhCH2); 4.00–3.88 (m, HꢀC(5)); 3.78–3.65 (m,
HꢀC(4), HaꢀC(6)); 3.55 (td, J¼9.5, 4.5, HbꢀC(6)); 3.05 (br. q, Jꢃ7.5, HꢀC(3)); 2.93 (s, 1 H), 2.90 (s,
3 H), 2.84 (s, 2 H) (Me2N); 2.65 (br. dd, Jꢃ14.5, 4.0, 0.33 H); 2.50–2.30 (m, 1.67 H) (2 HꢀC(2)); 1.45
(br. s, t-Bu). 13C-NMR (CDCl3, 75 MHz; 2 :1 mixture of diastereoisomers): signals of the major
diastereoisomer: 171.44 (s, C(1)); 155.04 (s, OC¼O); 138.49, 137.98 (2s); 137.34 (d, C(1’)); 128.23–127.47
(several d); 117.06 (t, C(2’)); 79.67 (d, C(4)); 79.05 (s, Me3C); 73.51 (t, PhCH2); 73.17 (t, PhCH2); 69.57 (t,
C(6)); 51.94 (d, C(5)); 41.68 (t, C(2)); 37.25, 35.42 (2q, Me2N); 34.61 (d, C(3)); 28.48 (q, Me3C); signals of
the minor diastereoisomer: 171.53 (s, C(1)); 155.31 (s, OC¼O); 138.84 (d, C(1’)); 138.32, 137.90 (2s);
128.23–127.47 (several d); 116.35 (d, C(2’)); 81.31 (d, C(4)); 79.32 (s, Me3C); 74.37 (t, PhCH2); 73.01 (t,
PhCH2); 68.81 (t, C(6)); 51.74 (d, C(5)); 42.17 (t, C(2)); 37.37, 35.47 (2q, Me2N); 33.56 (d, C(3)); 28.48 (q,
Me3C). HR-MALDI-MS: 519.2835 (65, [M þ Na]þ , C40H62N2NaO3þ ; calc. 519.2828), 397.2998 (100,
[MꢀBoc þ H]þ , C24H33N2Oþ3 ; calc. 397.2491).
(4R,5R,6S)- and (4S,5R,6S)-5-(Benzyloxy)-6-[(benzyloxy)methyl]-4-ethenylpiperidin-2-one (30a
and 30b, resp.). An ice-cold soln. of 29 (2 :1 mixture of diastereoisomers; 110 mg, 0.22 mmol) in CH2Cl2
(2 ml) was treated with CF3CO2H (0.5 ml), stirred at 258 for 8 h, and evaporated. A soln. of the residue in
THF (3 ml) was treated with 1m HCl (3 ml), stirred at 258 for 15 h, and kept at reflux for 5 h. The mixture
was diluted with AcOEt (100 ml) and washed with NaHCO3 soln. (100 ml). The aq. phase was extracted
with AcOEt (3ꢂ100 ml). The combined org. phases were washed with brine, dried (Na2SO4), and
1
evaporated. FC (AcOEt) gave 30a/30b 3 :1 (66 mg, 85%). Colourless gum. Rf (AcOEt) 0.35. H-NMR
(CDCl3, 300 MHz; 30a/30b 6 :1): signals of 30a: 7.39–7.21 (m, 10 arom. H); 5.99 (br. s, NH); 5.83 (ddd,
J¼17.4, 10.1, 7.4, HꢀC(1’)); 5.23 (dt, J¼17.4, 1.2, HaꢀC(2’)); 5.18 (dt, J¼10.2, 1.2, HbꢀC(2’)); 4.67, 4.39
(2d, J¼10.9, PhCH2); 4.48 (br. s, PhCH2); 3.66–3.56 (m, HꢀC(6), CHaꢀC(6)); 3.37–3.26 (m, HꢀC(5),
CHbꢀC(6)); 2.87–2.73 (m, HꢀC(4)); 2.54 (br. dd, J ¼ 17.7, 5.4, HaꢀC(3)); 2.31 (dd, J ¼ 17.7, 11.3,
HbꢀC(3)); signals of 30b: 5.98 (ddd, J¼17.4, 10.5, 6.3, HꢀC(1’)); 5.92 (br. s, NH); 5.21 (dt, J¼10.2, 1.2,
HaꢀC(2’)); 5.16 (dt, J¼17.1, 1.2, HbꢀC(2’)); 4.63, 4.51 (2d, J¼11.7, PhCH2); 4.50, 4.46 (2d, Jꢃ11.5,
PhCH2); 3.75–3.66 (m, HꢀC(6), CHaꢀC(6)); 2.62 (dd, J ¼ 17.4, 6.6, HaꢀC(3)); 2.40 (dd, J ¼ 17.4, 5.4,
HbꢀC(3)). HR-MALDI-MS: 352.1907 (100, [M þ H]þ , C22H26NO3þ ; calc. 352.1913).
Transformation of 30 into 31/32. Under N2 in a 25-ml flame-dried Schlenk flask, a soln. of 30a/30b 3 :1
(63 mg, 0.18 mmol) in dry CH2Cl2 (2 ml) was treated with dodec-1-ene (60 ml, 0.27 mmol) and a soln. of
[(RuCl2(CHPh)(PCy3)2] (7.6 mg, 9 mmol) in CH2Cl2 (1.6 ml), and stirred for 7 h at reflux. The mixture
was cooled to 258, treated with DMSO (0.5 ml), stirred for 15 h, and evaporated. FC (AcOEt/pentane
1:1!1:0) gave 31/32 3 :1 (63 mg, 70%).
(E)-4,6-Di-O-benzyl-5-N-{[(tert-butoxy)carbonyl]amino}-2,3,5-trideoxy-l-erythro-hex-2-enose
(33). A soln. of 28 (1.146 g, 2.68 mmol) in CH2Cl2 (15 ml) was treated with Dess–Martin periodinane
(15% in CH2Cl2, 9.1 ml, 3.22 mmol), stirred at 258 for 1.5 h, diluted with Et2O (200 ml), and filtered
through Celite (removal of the precipitated iodinane). The filtrate was washed with a 7:1 mixture 10%
aq. Na2S2O3/sat. aq. NaHCO3 (2ꢂ100 ml) and brine, dried (Na2SO4), and evaporated. FC (AcOEt/
pentane 1:9!1:4) gave 33 (1.11 g, 95%). Colourless oil. Rf (Et2O/pentane 2 :3) 0.46. [a]2D5 ¼ ꢀ14.75
(c¼1.0, CHCl3). IR (ATR): 3452w, 3357w, 3062w, 3030w, 2976w, 2929w, 2867w, 1712m, 1689s, 1496s,
1454m, 1391w, 1365m, 1318w, 1246w, 1163s, 1095s, 1065s, 1026m, 977m, 861w, 778w, 736s, 697s. 1H-NMR
(CDCl3, 300 MHz): 9.55 (d, J ¼ 8.1, HꢀC(1)); 7.38–7.24 (m, 10 arom. H); 6.82 (dd, J ¼ 15.9, 7.2,
HꢀC(3)); 6.26 (dd, J¼15.9, 8.1, HꢀC(2)); 5.01 (d, J¼9.0, NH); 4.58 (d, J¼11.7, PhCH); 4.50 (d, J¼11.7,
PhCH); 4.43 (d, J¼11.7, PhCH); 4.37 (d, J¼11.7, PhCH); 4.21 (t, J¼7.5, HꢀC(4)); 3.97–3.92 (m,
HꢀC(5)); 3.86 (br. dd, J¼9.3, 3.0, HaꢀC(6)); 3.53 (dd, J¼9.3, 3.9, HbꢀC(6)); 1.39 (s, t-Bu). 13C-NMR
(CDCl3, 75 MHz): 193.13 (d, C(1)); 155.18 (s, C¼O); 154.57 (d, C(3)); 137.62, 137.24 (2s); 134.12 (d,
C(2)); 128.41–127.75 (several d); 79.75 (s, Me3C); 78.23 (d, C(4)); 73.35 (t, PhCH2); 71.96 (t, PhCH2);
68.31 (t, C(6)); 52.96 (d, C(5)); 28.43 (q, Me3C). HR-MALDI-MS: 448.2097 (100, [M þ Na]þ
,
C25H31NNaOþ5 ; calc. 448.2100). Anal. calc. for C25H31NO5 (425.52): C 70.57, H 7.34, N 3.29; found:
C 70.76, H 7.48, N 3.27.

1704
CHEMISTRY & BIODIVERSITY – Vol. 6 (2009)
(4E,6R/S)-1,3-Di-O-benzyl-{[(tert-butoxy)carbonyl]amino}-2,4,5-trideoxy-6-C-undecyl-d-erythro-
hex-4-enitol (34). An ice-cold soln. of 33 (904 mg, 2.12 mmol) in Et2O (10 ml) was treated dropwise with
C11H23MgBr in Et2O (freshly prepared from 0.71 ml of C11H23Br (3.17 mmol) and 128.5 mg of Mg
(5.29 mmol) in 5 ml of Et2O), and stirred at 08 for 10 min and at 258 for 15 h. The mixture was cooled to
08, treated dropwise with sat. aq. NH4Cl soln., and diluted with H2O (20 ml) and Et2O (100 ml). After
separation of the layers, the aq. phase was extracted with Et2O (3ꢂ50 ml). The combined org. phases
were washed with brine, dried (Na2SO4), and evaporated. FC (Et2O/pentane 1:4!3 :7!1:3) gave 34
(1.06 g, 86%) as a 11:9 mixture of diastereoisomers that was used directly for the next step. Colourless
gum. Rf (AcOEt/hexane 1:4) 0.28. [a]2D5 ¼ ꢀ25.9 (c¼1.0, CHCl3). IR (ATR): 3446 (br.), 3062w, 3030w,
2923s, 2853m, 1712s, 1698s, 1497s, 1465m, 1454m, 1390w, 1365m, 1247w, 1206w, 1166s, 1091s, 1064s, 1027s,
973m, 911w, 861w, 776w, 733s, 696s. 1H-NMR (CDCl3, 300 MHz; 11:9 mixture of diastereoisomers):
7.37–7.23 (m, 10 arom. H); 5.766 (dd, J ¼ 15.6, 5.9, 0.45 H), 5.746 (dd, J ¼ 15.6, 5.9, 0.55 H), 5.63 (br. d,
J¼15.7, 1 H) (CH¼CH); 5.02–4.09 (br. s, NH); 4.54, 4.44 (2d, J¼11.8, PhCH2); 4.58, 4.35 (2d, J¼11.9,
0.9 H), 4.57, 4.32 (2d, J¼11.8, 1.1 H) (PhCH2); 4.15–4.07 (m, HꢀC(2)); 3.94 (br. t, J¼7.3, HꢀC(3));
3.88–3.82 (m, 2 HꢀC(1)); 3.55 (br. q, J¼5.7, HꢀC(6)); 1.84 (br. s, OH); 1.55–1.48 (m, 2 HꢀC(7)); 1.43,
1.42 (2s, Me3C); 1.34–1.25 (m, 18 H); 0.89 (t, J ¼ 6.7, Me). 13C-NMR (CDCl3, 75 MHz; 11:9 mixture of
diastereoisomers): 155.42 (s, C¼O); 138.26, 138.02 (2s); 128.27–127.59 (several d); 128.23 (d, C(4));
127.49 (d, C(5)); 79.34 (s, Me3C); 79.18 (d, C(3)); 73.17 (br. t, PhCH2); 70.67, 70.61 (2t, PhCH2); 72.18,
72.05 (2d, C(6)); 68.74 (br. t, C(1)); 53.41 (d, C(2)); 37.16 (t, C(7)); 32.04 (t); 29.75–29.49 (several t);
28.55, 28.52 (2q, Me3C); 25.64, 25.56 (2t); 22.83 (br. t); 14.29 (q, Me). HR-MALDI-MS: 450.2255 (100,
[M þ Na]þ , C25H33NNaOþ5 ; calc. 450.2256). Anal. calc. for C25H33NO5 ·0.3 H2O (432.94): C 69.31, H 7.82,
N 3.24; found: C 69.31, H 8.03, N 3.24.
Eschenmoser–Claisen Rearrangement of 34 with N,N-Dimethylacetamide Dimethyl Acetal. A soln.
of 34 (11:9 mixture of diastereoisomers; 870 mg, 1.5 mmol) in o-xylene (15 ml) was treated with N,N-
dimethylacetamide dimethyl acetal (0.54 ml, 4.5 mmol), stirred at 1458 for 15 h, cooled to 258, diluted
with AcOEt (100 ml), and washed with H2O (50 ml). The aq. phase was extracted with AcOEt (3ꢂ
100 ml). The combined org. phases were washed with brine, dried (Na2SO4), and evaporated. FC (Et2O/
pentane 1:1!9 :1) afforded 35a/35b 1:1 (878 mg, 90%). Slow FC (AcOEt/hexane 2 :3) of a small
amount gave pure samples of 35a and 35b.
4,6-Di-O-benzyl-5-{[(tert-butoxy)carbonyl]amino}-2,3,5-trideoxy-N,N-dimethyl-3-C-[(E)-tridec-1-
enyl]-l-arabino-hexonamide (35a). Colourless gum. Rf (AcOEt/hexane 2 :3) 0.40. [a]2D5 ¼ þ8.5 (c¼0.3,
CHCl3). IR (ATR): 3448w (br.), 3302w (br.), 3034w, 2923s, 2853m, 1710s, 1638s, 1496s, 1463m, 1454m,
1
1391m, 1364s, 1314w, 1248m, 1168s, 1095s, 1057s, 1027s, 971m, 911w, 861w, 772w, 733s, 696s. H-NMR
(CDCl3, 300 MHz): 7.36–7.23 (m, 10 arom. H); 5.54–5.38 (m, HꢀC(1’), HꢀC(2’)); 5.00 (d, J¼8.8, NH);
4.62, 4.57 (2d, J¼11.4, PhCH2); 4.49, 4.46 (2d, J¼11.9, PhCH2); 3.96–3.94 (m, HꢀC(5)); 3.70–3.67 (m,
HꢀC(4), HaꢀC(6)); 3.58 (dd, J¼9.7, 3.8, HbꢀC(6)); 2.91–2.84 (m, HꢀC(3)); 2.92, 2.87 (2s, Me2N); 2.61
(dd, J¼14.6, 4.0, HaꢀC(2)); 2.39 (dd, J¼14.8, 9.3, HbꢀC(2)); 1.97 (q, J ¼ 6.3, 2 HꢀC(3’)); 1.43 (s, t-Bu);
1.36–1.18 (m, 18 H); 0.88 (t, J¼6.7, Me). 13C-NMR (CDCl3, 75 MHz): 171.91 (s, Me2NC¼O); 155.41 (s,
OC¼O); 138.46, 137.99 (2s); 132.68 (d, C(1’)); 129.72 (d, C(2’)); 128.25–127.45 (several d); 81.58 (d,
C(4)); 79.12 (s, Me3C); 74.29, 72.86 (2t, 2 PhCH2); 68.63 (t, C(6)); 51.62 (d, C(5)); 41.40 (t, C(2)); 37.31,
37.29 (2q, Me2N); 35.30 (t); 34.06 (d, C(3)); 31.82, 32.55 (2t); 29.61–29.12 (several t); 28.31 (q, Me3C);
22.59 (t); 14.04 (q, Me). HR-MALDI-MS: 673.4543 (28, [M þ Na]þ , C40H62N2NaO3þ ; calc. 673.4556);
551.4192 (100, [MꢀBoc þ 2 H]þ , C35H55N2O3þ ; calc. 551.4213). Anal. calc. for C40H62N2O5 ·0.5 H2O
(659.54): C 73.81, H 9.62, N 4.24; found: C 73.87, H 9.43, N 4.25.
4,6-Di-O-benzyl-5-{[(tert-butoxy)carbonyl]amino}-2,3,5-trideoxy-N,N-dimethyl-3-C-[(E)-tridec-1-
enyl]-l-ribo-hexonamide (35b). Colourless gum. Rf (AcOEt/hexane 2 :3) 0.38. [a]2D5 ¼ ꢀ8.4 (c¼1.94,
CHCl3). IR (ATR): 3440w (br.), 3306w (br.), 3034w, 2923s, 2853m, 1713s, 1644s, 1497s, 1463m, 1454s,
1391m, 1364s, 1246m, 1221m, 1168s, 1107s, 1092s, 1056s, 1027s, 973m, 913w, 863w, 772s, 734s, 697s.
1H-NMR (CDCl3, 300 MHz): 7.36–7.25 (m, 10 arom. H); 5.54–5.39 (m, HꢀC(1’), HꢀC(2’)); 4.95 (d, J¼
9.7, NH); 4.62, 4.47 (2d, J¼11.6, PhCH2); 4.53, 4.48 (2d, J¼12.0, PhCH2); 3.97 (m, HꢀC(5)); 3.73–3.65
(m, HꢀC(4), HaꢀC(6)); 3.55 (dd, J¼9.4, 3.8, HbꢀC(6)); 2.97 (q, J¼6.4, HꢀC(3)); 2.87, 2.84 (2s, Me2N);
2.42–2.27 (m, 2 HꢀC(2)); 2.06–1.89 (m, 2 HꢀC(3’)); 1.43 (s, t-Bu); 1.36–1.18 (m, 18 H); 0.88 (t, J¼6.7,
Me). 13C-NMR (CDCl3, 75 MHz): 171.72 (s, Me2NC¼O); 155.03 (s, OC¼O); 138.55, 138.04 (2s); 133.52

CHEMISTRY & BIODIVERSITY – Vol. 6 (2009)
1705
(d, C(1’)); 128.34 (d, C(2’)); 128.19–127.40 (several d); 79.79 (s, Me3C); 79.77 (d, C(4)); 73.25, 73.12 (2t,
2 PhCH2); 69.66 (t, C(6)); 51.79 (d, C(5)); 41.15 (t, C(2)); 37.38, 37.35 (2q, Me2N); 35.43, 31.99 (2t); 32.80
(d, C(3)); 29.78–29.10 (several t); 28.48 (q, Me3C); 22.79 (t); 14.24 (q, Me). HR-MALDI-MS: 673.4552
(28, [M þ Na]þ , C40H62N2NaOþ3 ; calc. 673.4556); 551.4194 (100, [MꢀBoc þ 2 H]þ , C35H55N2Oþ3 ; calc.
551.4213). Anal. calc. for C40H62N2O5 (650.94): C 73.81, H 9.60, N 4.30; found: C 73.87, H 9.43, N 4.25.
Transformation of 35a/35b into the Lactams 31 and 32. An ice-cold soln. of 35a/35b 1:1 (803 mg,
1.23 mmol) in CH2Cl2 (6.0 ml) was treated with CF3CO2H (0.91 ml, 12.3 mmol), stirred at 258 for 15 h,
treated with H2O (3 ml), and stirred again for 1 h. The mixture was diluted with CH2Cl2 (50 ml) and
washed with H2O (2ꢂ50 ml). The combined aq. phases were extracted with CH2Cl2 (3ꢂ50 ml). The
combined org. phases were washed with H2O and brine, dried (Na2SO4), and evaporated. A soln. of the
residue in THF (10 ml) was treated with 1m HCl (2 ml) and stirred at reflux for 24 h. The mixture was
cooled to 258 and worked up as described above. FC (AcOEt/pentane 1:1!1:0) gave 31/32 1:1 (528 mg,
85%), which were separated by slow FC (AcOEt/hexane 1:1).
(4R,5R,6S)-5-(Benzyloxy)-6-[(benzyloxy)methyl]-4-[(E)-tridec-1-enyl)]piperidin-2-one (31). Col-
ourless gum. Rf (AcOEt/hexane 1:1) 0.29. [a]2D5 ¼ ꢀ20.2 (c¼1.0, CHCl3). IR (ATR): 3208w, 3062w,
3030w, 2922s, 2852m, 1667s, 1496w, 1466w, 1453m, 1401w, 1363w, 1317m, 1219s, 1097s, 1073s, 1028w, 968w,
1
911w, 772s, 732s, 695s. H-NMR (CDCl3, 300 MHz): 7.39–7.21 (m, 10 arom. H); 6.06 (br. s, NH); 5.62
(dtd, J ¼ 15.3, 7.1, 0.7, HꢀC(2’)); 5.34 (ddt, J¼15.3, 3.7, 1.3, HꢀC(1’)); 4.66, 4.39 (2d, J¼11.0, PhCH2);
4.50, 4.46 (2d, J¼12.3, PhCH2); 3.65–3.56 (m, HꢀC(6), CHaꢀC(6)); 3.34–3.23 (m, HꢀC(5),
CHbꢀC(6)); 2.77–2.66 (m, HꢀC(4)); 2.51 (dd, J ¼ 17.5, 5.2, HaꢀC(3)); 2.26 (dd, J ¼ 17.6, 11.2,
HbꢀC(3)); 2.03 (q, J ¼ 6.7, 2 HꢀC(3’)); 1.37–1.25 (m, 18 H); 0.88 (t, J¼6.7, Me). 13C-NMR (CDCl3,
75 MHz): 170.55 (s, C¼O); 137.56, 137.43 (2s); 133.52 (d, C(1’)); 128.87 (d, C(2’)); 128.55–127.86 (several
d); 77.67 (d, C(5)); 73.76, 73.35 (2t, 2 PhCH2); 71.00 (t, CH2ꢀC(6)); 56.69 (d, C(6)); 42.32 (d, C(4)); 35.60
(t, C(3)); 32.68, 31.94 (2t); 29.71–29.25 (several t); 22.71 (t); 14.14 (q, Me). HR-MALDI-MS: 506.3638
(100, [M þ H]þ , C33H48NOþ3 ; calc. 506.3634). Anal. calc. for C33H47NO3 (505.74): C 78.37, H 9.37, N 2.77;
found: C 78.20, H 9.28, N 2.75.
(4S,5R,6S)-5-(Benzyloxy)-6-[(benzyloxy)methyl]-4-[(E)-tridec-1-enyl)]piperidin-2-one (32). Col-
ourless gum. Rf (AcOEt/hexane 1:1) 0.24. [a]2D5 ¼ ꢀ50.0 (c¼1.05, CHCl3). IR (ATR): 3208w, 3062w,
3031w, 2922s, 2852m, 1665s, 1495w, 1465w, 1454m, 1406w, 1362w, 1330m, 1304w, 1253w, 1219w, 1090s,
1071m, 1027w, 968w, 934w, 772s, 732s, 695s. 1H-NMR (CDCl3, 300 MHz): 7.39–7.26 (m, 10 arom. H); 6.10
(br. s, NH); 5.60–5.48 (m, HꢀC(1’), HꢀC(2’)); 4.61, 4.50 (2d, J¼11.7, PhCH2); 4.50 (s, PhCH2); 3.74–
3.67 (m, HꢀC(6)); 3.61 (dd, J ¼ 9.0, 4.2, CHaꢀC(6)); 3.54 (dd, J ¼ 6.2, 3.3, HꢀC(5)); 3.34 (t, Jꢃ8.6,
CHbꢀC(6)); 2.82–2.78 (m, HꢀC(4)); 2.58 (dd, J ¼ 17.5, 6.5, HaꢀC(3)); 2.37 (dd, J ¼ 17.5, 5.4,
HbꢀC(3)); 2.05–1.99 (m, 2 HꢀC(3’)); 1.34–1.16 (m, 18 H); 0.89 (t, J¼6.7, Me). 13C-NMR (CDCl3,
75 MHz): 170.71 (s, C¼O); 137.58, 137.39 (2s); 133.23 (d, C(1’)); 128.39–127.64 (several d); 126.90 (d,
C(2’)); 74.99 (d, C(5)); 73.32, 71.60 (2t, 2 PhCH2); 71.06 (t, CH2ꢀC(6)); 53.66 (d, C(6)); 36.01 (d, C(4));
33.57 (t, C(3)); 32.65, 31.83 (2t); 29.60–29.09 (several t); 22.60 (t); 14.04 (q, Me). HR-MALDI-MS:
506.3635 (100, [M þ H]þ , C33H48NO3þ ; calc. 506.3634). Anal. calc. for C33H47NO3 (505.74): C 78.37, H
9.37, N 2.77; found: C 78.29, H 9.45, N 2.80.
Debenzylation of 31/32. An ice-cold soln. of 31/32 1:1 (440 mg, 0.87 mmol) in CH2Cl2 (20 ml) was
treated with anisole (0.57 ml, 5.23 mmol) and AlCl3 (465 mg, 3.49 mmol), stirred at 08 for 4 h, and treated
dropwise with 1m HCl (5 ml). After separation of the layers, the aq. phase was extracted with AcOEt (3ꢂ
100 ml). The combined org. phases were washed with H2O and brine, dried (Na2SO4), and evaporated.
FC (Lichoprep CN phase, CH2Cl2/MeOH 1:0!49 :1!97:3) gave 7 (113.5 mg, 40%) and 8 (99.3 mg,
35%).
(4R,5R,6S)-5-Hydroxy-6-(hydroxymethyl)-4-[(E)-tridec-1-enyl)]piperidin-2-one (7). Colourless
crystals. Rf (CH2Cl2/MeOH 9 :1) 0.30. M.p. 112.88. [a]2D5 ¼ þ10.1 (c¼0.5, CHCl3). IR (ATR): 3272w
(br.), 2961w, 2917s, 2849m, 1649s, 1490w, 1463w, 1415m, 1366w, 1317m, 1269w, 1170w, 1097w, 1075m,
1065s, 1032m, 960s, 905w, 758m, 731m, 646m. 1H-NMR (CD3OD, 300 MHz): 5.48 (dt, J ¼ 14.7, 6.3,
HꢀC(2’)); 5.36 (br. dd, J¼15.3, 7.5, HꢀC(1’)); 3.81 (dd, J¼11.1, 3.0, CHaꢀC(6)); 3.58 (dd, J¼11.7, 6.3,
CHbꢀC(6)); 3.41 (dd, J¼10.2, 9.3, HꢀC(5)); 3.22 (ddd, J¼9.0, 6.0, 3.3, HꢀC(6)); 2.54–2.45 (m,
HꢀC(4)); 2.37 (dd, J ¼ 17.4, 5.1, HaꢀC(3)); 2.21 (dd, J ¼ 17.4, 11.7, HbꢀC(3)); 2.05 (q, J ¼ 6.9,
2 HꢀC(3’)); 1.33–1.24 (m, 2 HꢀC(4’)); 1.24–1.20 (m, 16 H); 0.81 (t, Jꢃ6.7, Me). 13C-NMR (CD3OD,

1706
CHEMISTRY & BIODIVERSITY – Vol. 6 (2009)
75 MHz): 173.48 (s, C¼O); 133.79 (d, C(1’)); 130.29 (d, C(2’)); 69.37 (d, C(5)); 62.92 (t, CH2ꢀC(6));
60.96 (d, C(6)); 43.67 (d, C(4)); 36.42 (t, C(3)); 33.49, 32.82 (2t); 30.51–30.03 (several t); 23.50 (t); 14.23
(q, Me). HR-MALDI-MS: 326.2688 (100, [M þ H]þ , C19H36NO3þ ; calc. 326.2695). Anal. calc. for
C19H35NO3 (325.49): C 70.11, H 10.84, N 4.30; found: C 70.24, H 10.74, N 4.37.
(4S,5R,6S)-5-Hydroxy-6-(hydroxymethyl)-4-[(E)-tridec-1-enyl)]piperidin-2-one (8). Colourless
crystals. Rf (CH2Cl2/MeOH 9 :1) 0.27. M.p. 114.98. [a]2D5 ¼ ꢀ24.6 (c¼1.0, THF). IR (ATR): 3243m,
3112w, 2954w, 2919s, 2850m, 1638s, 1485m, 1467m, 1419w, 1399m, 1344w, 1318m, 1254w, 1144w, 1086w,
1051m, 1033w, 1004w, 964m, 948m, 891w, 765m, 749m, 720w, 682w, 658w. 1H-NMR (CD3OD, 300 MHz):
5.64–5.51 (m, HꢀC(1’), HꢀC(2’)); 3.90 (dd, J¼4.8, 3.3, HꢀC(5)); 3.59 (dd, J¼11.1, 6.0, CHaꢀC(6));
3.55 (dd, J¼11.4, 5.7, CHbꢀC(6)); 3.35 (td, J¼5.7, 4.5, HꢀC(6)); 2.70–2.65 (m, HꢀC(4)); 2.42 (dd, J ¼
17.7, 8.7, HaꢀC(3)); 2.30 (dd, J ¼ 17.4, 5.7, HbꢀC(3)); 2.05 (q, J ¼ 6.9, 2 HꢀC(3’)); 1.40–1.20 (m, 18 H);
0.90 (t, Jꢃ6.8, Me). 13C-NMR (CD3OD, 75 MHz): 173.83 (s, C¼O); 133.25 (d, C(1’)); 129.28 (d, C(2’));
67.65 (d, C(5)); 63.62 (t, CH2ꢀC(6)); 60.02 (d, C(6)); 38.96 (d, C(4)); 33.53 (t, C(3)); 32.80 (t); 30.48–
30.00 (several t); 23.48 (t); 14.21 (q, Me). HR-MALDI-MS: 326.2690 (100, [M þ H]þ , C19H36NO3þ ; calc.
326.2695). Anal. calc. for C19H35NO3 (325.49): C 70.11, H 10.84, N 4.30; found: C 70.14, H 10.70, N 4.35.
X-Ray Analysis of 7. In a 5-ml round-bottomed flask, a soln. of 7 (ca. 20 mg) in MeOH (5 ml) was
treated dropwise with H2O until the turbidity persisted for ca. 1 min, and treated with MeOH (2 ml) to
obtain a clear soln. The flask was closed with a perforated Al foil, and kept undisturbed. The plate-like
crystals formed within 2 d were suitable for X-ray analysis. Dimensions: 0.3ꢂ0.08ꢂ0.005 mm.
Colourless crystals: C19H35NO3 (325.493), orthorhombic P212121; a¼4.9903(3), b¼9.7480(6), c ¼
39.811(3) ꢃ, V¼1936.6(2) ꢃ3, Z¼4, Dcalc ¼1.116 Mg/m3. All reflections were measured using a Bruker
Nonius-Kappa CCD diffractometer (MoKa radiation, l¼0.71073) at 22 K. 6904 Measured reflections,
2448 independent reflections, 1459 observed reflections. Refinement of F2: full-matrix least-squares
refinement, R(all)¼0.2050, R(gt)¼0.1305, wR(ref)¼0.2749, wR(gt)¼0.2473. All diagrams and
calculations were performed using maXus (Bruker Nonius, Delft & MacScience, Japan). Programme
used to solve structure: SIR97. Programme used to refine structure: SHELXL-97
X-Ray Analysis of 8. In a 5-ml round-bottomed flask, a soln. of 8 (ca. 20 mg) in MeOH (5 ml) was
treated dropwise with H2O until the turbidity persisted for ca. 1 min, and treated with MeOH (2 ml) to
obtain a clear soln. The flask was closed with a perforated Al foil, and kept undisturbed. The plate-like
crystals formed within 2 d were suitable for X-ray analysis. Dimensions: 0.36ꢂ0.18ꢂ0.1 mm. Colourless
crystals: C19H35NO3 (325.493), monoclinic P21; a¼5.4658(3), b¼6.5116(4), c ¼ 27.989(2) ꢃ, V¼993.05
(10) ꢃ3, Z¼2, Dcalc ¼1.089 Mg/m3. All reflections were measured using a Bruker Nonius-Kappa CCD
diffractometer (MoKa radiation, l¼0.71073) at 223 K. 3900 Measured reflections, 2364 independent
reflections, 2055 observed reflections. Refinement of F2: full-matrix least-squares refinement, R(all)¼
0.0919, R(gt)¼0.0792, wR(ref)¼0.2307, wR(gt)¼0.2179. All diagrams and calculations were performed
using maXus (Bruker Nonius, Delft & MacScience, Japan). Programme used to solve structure: SIR97.
Programme used to refine structure: SHELXL-97.
Hydrogenation of 31/32. A soln. of 31/32 1:1 (200 mg, 0.4 mmol) in MeOH (5 ml) was treated with
10% Pd/C (40 mg) and AcOH (0.5 ml), stirred at 258 under 6 bar of H2 for 20 h, and filtered through
Celite (washing with MeOH). The combined filtrate and washings were evaporated. A soln. of the
residue in MeOH was adsorbed on silica gel and submitted to a FC (CH2Cl2/MeOH 1:0!95 :5!9 :1)
affording 15 (61.5 mg, 47%) and 16 (52.4 mg, 40%).
(4R,5R,6S)-5-Hydroxy-6-(hydroxymethyl)-4-(tridecyl)piperidin-2-one (15). Colourless crystals. Rf
(CH2Cl2/MeOH 9 :1) 0.40. M.p. 103.28. [a]2D5 ¼ þ23.8 (c¼0.25, MeOH). IR (ATR): 3423w (br.), 3253w,
3185w, 3063w, 2954w, 2918m, 2849m, 1620m, 1488w, 1470m, 1415w, 1373w, 1283w, 1258w, 1219m, 1138w,
1071m, 1044m, 810w, 772s, 719w, 673w. 1H-NMR (CD3OD, 300 MHz): 3.82 (dd, J¼11.1, 3.0, CHaꢀC(6));
3.57 (dd, J¼11.4, 6.3, CHbꢀC(6)); 3.33 (dd, J¼10.2, 9.0, HꢀC(5)); 3.19 (ddd, J¼9.0, 5.7, 3.0, HꢀC(6));
2.47 (dd, J ¼ 17.7, 4.8, HaꢀC(3)); 1.99 (dd, J ¼ 17.1, 11.7, HbꢀC(3)); 1.89–1.74 (m, HꢀC(4)); 1.29–1.08
(m, 24 H); 0.89 (t, Jꢃ6.3, Me). 13C-NMR (CD3OD, 75 MHz): 174.44 (s, C¼O); 66.10 (d, C(5)); 63.91 (t,
CH2ꢀC(6)); 60.88 (d, C(6)); 34.75 (d, C(4)); 33.21 (t, C(3)); 32.64, 31.26 (2t); 30.45–30.04 (several t);
27.46, 23.30 (2t); 14.23 (q, Me). HR-MALDI-MS: 328.2849 (100, [M þ H]þ , C19H38NO3þ ; calc. 328.2852).
Anal. calc. for C19H37NO3 (327.51): C 69.68, H 11.39, N 4.28; found: C 69.40, H 11.53, N 4.33.

CHEMISTRY & BIODIVERSITY – Vol. 6 (2009)
1707
(4S,5R,6S)-5-Hydroxy-6-(hydroxymethyl)-4-(tridecyl)piperidin-2-one (16). Colourless crystals. Rf
(CH2Cl2/MeOH 9 :1) 0.37. M.p. 145.38. IR (ATR): 3350w (br.), 3277w (br.), 3237w (br.), 2949w,
2918m, 2848m, 1642m, 1486w, 1467w, 1421w, 1402w, 1320w, 1113w, 1071w, 1019s, 1004w, 960m, 721w.
1H-NMR (CD3OD, 300 MHz): 3.93 (br. t, J¼2.6, HꢀC(5)); 3.52 (m, CH2ꢀC(6)); 3.41 (ddd, J¼6.8, 5.7,
2.9, HꢀC(6)); 2.24–2.20 (m, 2 HꢀC(3)); 2.00–1.89 (m, HꢀC(4)); 1.58–1.49 (m, 2 HꢀC(1’)); 1.33–1.29
(m, 22 H); 0.90 (t, J¼6.8, Me). 13C-NMR (CD3OD, 75 MHz): 174.44 (s, C¼O); 66.10 (d, C(5)); 63.91 (d,
C(6)); 60.88 (t, CH2ꢀC(6)); 34.75 (d, C(4)); 33.21 (t, C(3)); 32.64, 31.26 (2t); 30.45–30.04 (several t);
27.46, 23.30 (2t); 13.99 (q, Me). HR-MALDI-MS: 328.2850 (100, [M þ H]þ , C19H38NO3þ ; calc. 328.2852).
Anal. calc. for C19H37NO3 (327.51): C 69.68, H 11.39, N 4.28; found: C 69.59, H 11.42, N 4.37.
X-Ray Analysis of 15. In a 5-ml round-bottomed flask, a soln. of 15 (ca. 20 mg) in hot MeOH (5 ml)
was closed with a perforated Al foil, and kept undisturbed for 7 d at r.t. affording plate-like crystals
suitable for X-ray analysis. Dimensions: 0.4ꢂ0.2ꢂ0.005 mm. Colourless crystals: C19H37NO3 (327.509),
monoclinic P21; a¼5.4911 (2), b¼6.8227 (3), c ¼ 26.3831 (12) ꢃ, b¼92.015 (2), V¼987.81 (7) ꢃ3, Z¼2,
Dcalc ¼1.101 Mg/m3. All reflections were measured using a Bruker Nonius-Kappa CCD diffractometer
(MoKa radiation, l¼0.71073) at 173 K. 5363 Measured reflections, 3077 independent reflections, 2246
observed reflections. Refinement of F2: full-matrix least-squares refinement, R(all)¼0.0842, R(gt)¼
0.0516, wR(ref)¼0.1464, wR(gt)¼0.1226. All diagrams and calculations were performed using maXus
(Bruker Nonius, Delft & MacScience, Japan). Programme used to solve structure: SIR97. Programme
used to refine structure: SHELXL-97.
(4R,5R,6S)-6-(Azidomethyl)-5-hydroxy-4-[(E)-tridec-1-enyl)]piperidin-2-one (36). An ice-cold
soln. of [4-(dimethylamino)phenyl](diphenyl)phosphine (48.4 mg, 0.16 mmol) in THF (1 ml) was
treated dropwise with diethyl azodicarboxylate (40% in toluene; 0.7 ml, 0.16 mmol), keeping the mixture
colourless. The mixture was stirred at 08 for 15 min, when the initially formed colourless precipitate was
dissolved completely. The soln. was treated dropwise with a soln. of 7 (25.8 mg, 0.08 mmol) in THF
(1 ml). The clear homogeneous soln. was treated with freshly prepared 0.8m HN3 soln. in toluene (0.3 ml,
0.24 mmol), and stirred at 08 for 1 h, and at 258 for 2 h. After dilution with AcOEt (50 ml), the mixture
was washed with 1m HCl (2ꢂ25 ml). The combined aq. phases were extracted with AcOEt (3ꢂ50 ml).
The combined org. phases were washed with sat. aq. NaHCO3 soln., H2O, and brine, dried (Na2SO4), and
evaporated. FC (AcOEt/pentane 1:1!3 :2) gave 36 (22 mg, 80%). Colourless crystals. Rf (CH2Cl2/
MeOH 9 :1) 0.32. M.p. 76.98. [a]2D5 ¼ ꢀ15.8 (c¼0.75, CHCl3). IR (ATR): 3288w (br.), 3221w (br.),
2957w, 2921s, 2852s, 2103s, 1652s, 1463m, 1445m, 1405m, 1347w, 1311m, 1279m, 1178w, 1105w, 1064m,
965m, 865w. 1H-NMR (CDCl3, 300 MHz): 6.65 (s, NH); 5.69 (dt, J ¼ 15.2, 6.8, HꢀC(2’)); 5.16 (br. dd, J¼
15.3, 8.4, HꢀC(1’)); 3.83–3.76 (m, HꢀC(5)); 3.44–3.10 (m, CH2ꢀC(6), HꢀC(6)); 2.52 (dd, J¼16.5, 5.1,
HaꢀC(3)); 2.48–2.39 (m, HꢀC(4)); 2.37 (d, J¼2.0, OH); 2.22 (dd, J¼16.2, 10.8, HbꢀC(3)); 2.05 (q, Jꢃ
6.7, 2 HꢀC(3’)); 1.41–1.21 (m, 18 H); 0.87 (t, J¼6.7, Me). 13C-NMR (CD3OD, 75 MHz): 170.77 (s,
C¼O); 136.81 (d, C(1’)); 127.67 (d, C(2’)); 60.08 (d, C(5)); 57.31 (d, C(6)); 53.49 (t, CH2ꢀC(6)); 43.85 (d,
C(4)); 35.75 (t, C(3)); 32.66, 32.01 (2t); 29.76–29.29 (several t); 22.81 (t); 14.26 (q, Me). HR-MALDI-
MS: 351.2755 (100, [M þ H]þ , C19H35N4O2þ ; calc. 351.2760). Anal. calc. for C19H34N4O2 (350.50): C 65.11,
H 9.78, N 15.98; found: C 65.35, H 9.74, N 15.84.
(4R,5R,6S)-6-(Aminomethyl)-5-hydroxy-4-[(E)-tridec-1-enyl)]piperidin-2-one (17). An ice-cold
soln. of 36 (18 mg, 0.05 mmol) in THF (2 ml) was treated dropwise with 1m Me3P in THF (0.1 ml,
0.1 mmol), stirred at 08 for 5 h, treated with 1m NaOH (0.5 ml), and stirred at 258 for 15 h. After dilution
with AcOEt (20 ml), the mixture was washed with H2O (25 ml). The aq. phase was extracted with AcOEt
(3ꢂ20 ml). The combined org. phases were washed with H2O and brine, dried (Na2SO4), and
evaporated. A suspension of residue in pentane was cooled to 58, and the supernatant was decanted. This
process was repeated 5 times, until TLC showed absence of pentane-soluble impurities. The precipitate
was dried in vacuo to afford 17 (15 mg, 90%). Colourless syrup. Rf (NH2 phase silica gel; CH2Cl2/MeOH
9 :1) 0.32. [a]2D5 ¼ þ9.8 (c¼0.15, CHCl3). IR (ATR): 3440w (sh), 3352w, 3281w (br.), 2957w, 2920s, 2850s,
1646s, 1466w, 1416w, 1326w, 1270w, 1154w, 1058m, 1022w, 965w, 865w, 721w. 1H-NMR (CD3OD,
300 MHz): 5.58 (dtd, J ¼ 15.3, 6.6, 0.6, HꢀC(2’)); 5.36 (ddt, J¼15.3, 7.5, 1.2, HꢀC(1’)); 3.36 (dd, J¼10.1,
8.8, HꢀC(5)); 3.19–3.13 (m, HꢀC(6)); 2.96 (dd, J¼13.5, 3.9, CHaꢀC(6)); 2.78 (dd, J¼13.5, 5.5,
CHbꢀC(6)); 2.53–2.43 (m, HꢀC(4)); 2.37 (dd, J ¼ 17.6, 5.3, HaꢀC(3)); 2.23 (dd, J ¼ 17.5, 11.8,
HbꢀC(3)); 2.05 (q, J¼6.7, 2 HꢀC(3’)); 1.43–1.23 (m, 18 H); 0.90 (t, J¼6.8, Me). 13C-NMR (CD3OD,

1708
CHEMISTRY & BIODIVERSITY – Vol. 6 (2009)
75 MHz): 173.05 (s, C¼O); 134.20 (d, C(1’)); 130.87 (d, C(2’)); 71.30 (d, C(5)); 63.56 (d, C(6)); 40.01 (t,
CH2ꢀC(6)); 38.72 (t, C(3)); 35.90 (d, C(4)); 33.00, 32.58 (2t); 29.65–29.21 (several t); 22.74 (t); 14.40 (q,
Me). HR-MALDI-MS: 325.2849 (100, [M þ H]þ , C19H37N2O2þ ; calc. 325.2855).
(4R,5R,6S)-6-(Aminomethyl)-5-hydroxy-4-(tridecyl)piperidin-2-one (18). A soln. of 36 (20 mg,
0.06 mmol) in MeOH (3 ml) was treated with 10% Pd/C (10 mg, 50 wt-%) stirred at 258 under 8 bar of H2
for 20 h, and filtered through Celite (washings with MeOH). Evaporation of the combined filtrate and
washings, and FC (CH2Cl2/MeOH 9 :1) gave 18 (17.7 mg, 95%). Colourless syrup solidifying upon
standing at 58. Rf (NH2 phase; CH2Cl2/MeOH 9 :1) 0.27. [a]2D5 ¼ þ33.6 (c¼0.21, CHCl3). IR (ATR):
3387w (sh), 3282w (br.), 2953w, 2918s, 2850s, 1629s, 1470w, 1408w, 1320w, 1261w, 1080m, 845w, 772w,
1
718w. H-NMR (CD3OD, 300 MHz): 3.28 (t, J¼9.9, HꢀC(5)); 3.16–3.10 (m, HꢀC(6)); 2.97 (dd, J¼
13.4, 3.9, CHaꢀC(6)); 2.78 (dd, J¼13.4, 5.5, CHbꢀC(6)); 2.47 (dd, J ¼ 17.5, 4.9, HaꢀC(3)); 2.00 (dd, J ¼
17.6, 11.8, HbꢀC(3)); 1.89–1.74 (m, HꢀC(4)); 1.42–1.22 (m, 20 H); 0.90 (t, J¼6.7, Me). 13C-NMR
(CD3OD, 75 MHz): 174.26 (s, C¼O); 70.19 (d, C(5)); 63.25 (d, C(6)); 61.33 (t, CH2ꢀC(6)); 39.72 (t,
C(3)); 35.93 (d, C(4)); 33.07, 32.53 (2t); 30.97–30.48 (several t); 27.02, 23.74 (2t); 14.47 (q, Me). HR-
MALDI-MS: 327.3010 (100, [M þ H]þ , C19H39N2O2þ ; calc. 327.3012).
(4S,5R,6S)-5-Hydroxy-6-{[(4-methylphenyl)sulfonyl]oxy}methyl)-4-[(E)-tridec-1-enyl)]piperidin-
i
2-one (37). A soln. of 8 (20 mg, 0.061 mmol) in CH2Cl2 (10 ml) was treated with Pr2NEt (101 ml,
0.6 mmol), TsCl (17.6 mg, 0.092 mmol), and 4-(dimethylamino)pyridine (0.8 mg, 0.006 mmol), and
stirred at 258 for 22 h. After dilution with CH2Cl2 and H2O, the aq. layer was separated and extracted with
CH2Cl2 (3ꢂ20 ml). The combined org. phases were dried (Na2SO4) and evaporated. The residue was
filtered through a short pad of silica gel (AcOEt/pentane 1:1!4 :1) to afford crude 37 (24 mg, 82%),
which was used directly for the next step. Colourless syrup. Rf (CH2Cl2/MeOH 9 :1) 0.48. IR (ATR):
3541w (sh), 3350w (br.), 2953w, 2923s, 2853m, 1652s, 1599w, 1463m, 1403m, 1361s, 1308w, 1189m, 1176s,
1096m, 1067w, 974m, 947m, 911w, 830w, 813m, 786m, 733w, 665m. 1H-NMR (CDCl3, 300 MHz): 7.80–7.78
(m, 2 arom. H); 7.37–7.35 (m, 2 arom. H); 5.77 (s, NH); 5.65 (dt, J ¼ 15.6, 6.8, HꢀC(2’)); 5.40 (br. dd, J¼
15.5, 7.8, HꢀC(1’)); 4.24 (dd, J¼10.1, 3.8, CHaꢀC(6)); 3.98 (dd, J¼10.2, 7.4, CHbꢀC(6)); 3.74 (td, J¼7.1,
3.6, HꢀC(5)); 3.58–3.51 (m, HꢀC(6)); 2.70–2.62 (m, HꢀC(4)); 2.48–2.46 (m, 2 HꢀC(3)); 2.46 (s,
MeC6H4); 2.05 (q, J ¼ 6.5, 2 HꢀC(3’)); 1.86 (d, J¼7.1, OH); 1.41–1.26 (m, 18 H); 0.88 (t, J¼6.6, Me).
13C-NMR (CDCl3, 100 MHz): 170.34 (s, C¼O); 145.47 (s); 136.66 (d, C(1’)); 132.36 (s); 130.11 (d, 2 CH);
127.98 (d, 2 CH); 125.37 (d, C(2’)); 70.26 (t, CH2ꢀC(6)); 66.80 (d, C(5)); 55.34 (d, C(6)); 39.45 (d, C(4));
33.55 (t, C(3)); 32.71, 31.91 (2t); 29.65–29.19 (several t); 22.67 (t); 21.68 (q, MeC6H4); 14.09 (q, Me). HR-
MALDI-MS: 480.2781 (100, [M þ H]þ , C26H42NO5Sþ ; calc. 480.2784).
(4S,5R,6S)-6-(Azidomethyl)-5-hydroxy-4-[(E)-tridec-1-enyl)]piperidin-2-one (38). A soln. of crude
37 (15 mg, 0.032 mmol) in DMF (1.5 ml) was treated with NaN3 (20.4 mg, 0.21 mmol) and kept at 1008
for 15 h. The mixture was cooled to r.t., poured into H2O (15 ml), and extracted with AcOEt (3ꢂ30 ml).
The combined org. layers were washed with brine (50 ml), dried (Na2SO4), and evaporated. FC (AcOEt/
pentane 2 :4!1:0) gave 38 (5.6 mg, 50%). Colourless gum. Rf (AcOEt) 0.52. IR (ATR): 3288w (br.),
2923w, 2853s, 2104s, 1649s, 1463m, 1445m, 1347w, 1311w, 1279w, 1178w, 1105w, 1064m, 965w, 825w.
1H-NMR (CDCl3, 300 MHz): 5.89 (s, NH); 5.69 (dt, J ¼ 15.6, 6.8, HꢀC(2’)); 5.45 (br. dd, J¼15.5, 7.8,
HꢀC(1’)); 3.76–3.65 (m, HꢀC(5), CHaꢀC(6)); 3.41–3.33 (m, HꢀC(6), CHbꢀC(6)); 2.73–2.67 (m,
HꢀC(4)); 2.52–2.50 (m, 2 HꢀC(3)); 2.07 (q, J ¼ 6.5, 2 HꢀC(3’)); 1.61 (br. s, OH); 1.39–1.19 (m, 18 H);
0.88 (t, J¼6.6, Me). HR-MALDI-MS: 351.2754 (52, [M þ H]þ , C19H35N4O2þ ; calc. 351.2760).
(4S,5R,6S)-6-(Aminomethyl)-5-hydroxy-4-[(E)-tridec-1-enyl)]piperidin-2-one (19). Analogously to
the preparation of 17, 38 (2.5 mg, 7.1 mmol) was transformed into 19 (1.4 mg, 60%). Colourless syrup. Rf
(NH2-phase silica gel; CH2Cl2/MeOH 9 :1) 0.20. IR (ATR): 3440w (sh), 3351w, 3281w (br.), 2955w,
2918s, 2852s, 1652s, 1468w, 1411w, 1273w, 1160w, 1021w, 960w, 867w, 722w. 1H-NMR (CD3OD, 300 MHz):
5.61 (dt, J ¼ 15.6, 6.8, HꢀC(2’)); 5.45 (br. dd, J¼15.5, 7.8, HꢀC(1’)); 3.81–3.73 (m, HꢀC(5), HꢀC(6));
3.14–3.05 (m, CH2ꢀC(6)); 2.69–2.65 (m, HꢀC(4)); 2.49–2.45 (m, 2 HꢀC(3)); 2.05 (q, J ¼ 6.5,
2 HꢀC(3’)); 1.31–1.20 (m, 18 H); 0.85 (t, J¼6.6, Me). HR-MALDI-MS: 325.2841 (68, [M þ H]þ
,
C19H37N2Oþ2 ; calc. 325.2855).
(4S,5R,6S)-6-(Aminomethyl)-5-hydroxy-4-(tridecyl)piperidin-2-one (20). Analogously to the prep-
aration of 18, 38 (1.5 mg, 4.3 mmol) was transformed into 20 (1.1 mg, 80%). Colourless gum. Rf (NH2
phase; CH2Cl2/MeOH 9 :1) 0.20. IR (ATR): 3381w (sh), 3286w (br.), 2953w, 2920s, 1632s, 1475w, 1408w,

CHEMISTRY & BIODIVERSITY – Vol. 6 (2009)
1709
1320w, 1266w, 1084m, 846w, 772w, 724w. 1H-NMR (CD3OD, 300 MHz): 3.53–3.41 (m, HꢀC(5),
HꢀC(6)); 3.10–3.01 (m, CH2ꢀC(6)); 2.23–2.31 (m, 2 HꢀC(3)); 2.25–2.20 (m, HꢀC(4)); 1.39–1.20 (m,
20 H); 0.87 (t, J¼6.6, Me). HR-MALDI-MS: 327.3013 (100, [M þ H]þ , C19H39N2O2þ ; calc. 327.3012).
(4R,5R,6S)-5-Hydroxy-6-({[(4-methylphenyl)sulfonyl]oxy}methyl)-4-[(E)-tridec-1-enyl)]piperidin-
2-one (39). Analogously to the preparation of 37, 7 (40 mg, 0.123 mmol) was transformed into 39. The
residue was filtered through a short pad of silica gel (AcOEt/pentane 1:1!4 :1) to afford crude 39
(52 mg, 88%), which was used directly for the next step. Colourless syrup. Rf (CH2Cl2/MeOH 9 :1) 0.64.
IR (ATR): 3541w (br.), 3345w (br.), 3221w (sh), 2922s, 2852m, 1653s, 1598w, 1456m, 1403m, 1358s,
1324m, 1189m, 1174s, 1096m, 1019w, 968s, 920m, 878w, 812s, 789m, 706m, 667s. 1H-NMR (CDCl3,
400 MHz): 7.81–7.78 (m, 2 arom. H); 7.38–7.35 (m, 2 arom. H); 5.85 (s, NH); 5.85 (dt, J ¼ 15.2, 6.8,
HꢀC(2’)); 5.12 (br. dd, J¼15.2, 8.4, HꢀC(1’)); 4.36 (dd, J¼10.2, 2.6, CHaꢀC(6)); 4.03 (dd, J¼10.2, 7.5,
CHbꢀC(6)); 3.51 (td, Jꢃ8.2, 2.4, HꢀC(6)); 3.30 (td, J¼9.6, 2.1, irrad. at 3.51!br. d, J¼9.6, HꢀC(5));
2.51 (dd, J ¼ 16.2, 5.4, HaꢀC(3)); 2.58–2.39 (m, HꢀC(4)); 2.46 (s, MeC6H4); 2.22 (dd, J ¼ 16.5, 11.1,
HbꢀC(3)); 2.16 (d, J¼2.1, OH); 2.04 (q, J ¼ 6.9, 2 HꢀC(3’)); 1.42–1.18 (m, 18 H); 0.88 (t, J¼6.7, Me).
13C-NMR (CDCl3, 75 MHz): 169.93 (s, C¼O); 145.31 (s); 137.19 (d, C(1’)); 132.22 (s); 130.00 (d, 2 CH);
127.89 (d, 2 CH); 127.31 (d, C(2’)); 70.08 (t, CH2ꢀC(6)); 67.95 (d, C(5)); 56.76 (d, C(6)); 43.73 (d, C(4));
35.41 (t, C(3)); 32.42, 31.81 (2t); 29.51–29.05 (several t); 22.58 (t); 21.59 (q, MeC6H4); 14.02 (q, Me). HR-
MALDI-MS: 480.2775 (100, [M þ H]þ , C26H42NO5Sþ ; calc. 480.2784).
(4R,5R,6S)-6-[(Dimethylamino)methyl]-5-hydroxy-4-[(E)-tridec-1-enyl)]piperidin-2-one (21). A
soln. of crude 39 (47.9 mg, 0.1 mmol) in THF (2 ml) was treated with 40% Me2NH in H2O (1 ml) and
stirred at 858 for 18 h. After cooling to 258, the mixture was diluted with H2O and extracted with AcOEt
(4ꢂ30 ml). The combined org. phases were washed with H2O (2ꢂ50 ml), dried (Na2SO4), and
evaporated. FC (CH2Cl2/MeOH 9 :1) gave 21 (33.5 mg, 95%). Rf (CH2Cl2/MeOH 9 :1) 0.38. [a]D25
¼
þ13.2 (c¼0.26, CHCl3). IR (ATR): 3456w, 3180w, 3016m, 2970m, 2949s, 2919s, 2850m, 2779w, 1663s,
1540m (br.), 1435m, 1403m, 1365s, 1228s, 1216s, 1091w, 1029w, 957w, 894w, 749w, 721w. 1H-NMR (CDCl3,
300 MHz): 6.02 (s, NH); 5.64 (dt, J¼15.1, 6.8, HꢀC(2’)); 5.26 (dd, J¼15.2, 7.7, HꢀC(1’)); 4.32 (br. s,
OH); 3.35–3.28 (m, HꢀC(5), HꢀC(6)); 2.64 (dd, J¼12.0, 6.4, CHaꢀC(6)); 2.55–2.47 (m, HaꢀC(3),
HꢀC(4)); 2.37–2.16 (m, HbꢀC(3), CHbꢀC(6)); 2.28 (s, Me2N); 2.06 (q, J¼6.7, 2 HꢀC(3’)); 1.43–1.19
(m, 18 H); 0.88 (t, J¼6.6, Me). 13C-NMR (CDCl3, 75 MHz): 170.58 (s, C¼O); 135.06 (d, C(1’)); 128.41
(d, C(2’)); 73.50 (d, C(5)); 63.90 (t, CH2ꢀC(6)); 53.61 (d, C(6)); 45.73 (q, Me2N); 43.65 (d, C(4)); 35.67 (t,
C(3)); 32.60, 31.94 (2t); 29.63–29.20 (several t); 22.71 (t); 14.14 (q, Me). HR-MALDI-MS: 353.3162
(100, [M þ H]þ , C21H41N2Oþ2 ; calc. 353.3168).
(4R,5R,6S)-6-[(Dimethylamino)methyl]-5-hydroxy-4-(tridecyl)piperidin-2-one (22). A soln. of 21
(15 mg, 0.043 mmol) in AcOEt (3 ml) was treated with 10% Pd/C (3 mg, 20 wt%), stirred at 258 under
8 bar of H2 for 24 h, and filtered through Celite (washing with AcOEt). Evaporation of the combined
filtrate and washings, and FC (CH2Cl2/MeOH 9 :1) yielded 22 (14.5 mg, 97%). Colourless syrup. Rf
(CH2Cl2/MeOH 9 :1) 0.28. [a]2D5 ¼ þ44.1 (c¼0.56, CHCl3). IR (ATR): 3363w, 3290w, 3183w, 3066w,
2954w, 2919s, 2850m, 2829w, 2784w, 1661s, 1468m, 1403w, 1306w, 1265w, 1183w, 1082m, 1043w, 1024w,
1
885w, 840w, 824w, 747m, 719w. H-NMR (CDCl3, 300 MHz): 6.15, 5.85 (2s, NH, OH); 3.38–3.25 (m,
HꢀC(5), HꢀC(6)); 2.66–2.52 (m, HaꢀC(3), CHaꢀC(6)); 2.40 (dd, J¼12.1, 4.1, CHbꢀC(6)); 2.32 (s,
Me2N); 2.04–1.81 (m, HbꢀC(3), HꢀC(4)); 1.39–1.07 (m, 24 H); 0.88 (t, J¼6.6, Me). 13C-NMR (CDCl3,
75 MHz): 171.98 (s, C¼O); 75.99 (d, C(5)); 64.98 (t, CH2ꢀC(6)); 53.38 (d, C(6)); 45.95 (q, Me2N); 38.64
(d, C(4)); 35.13 (t, C(3)); 31.94, 31.11 (2t); 29.79–29.37 (several t); 25.83, 22.70 (2t); 14.13 (q, Me). HR-
MALDI-MS: 355.3321 (100, [M þ H]þ , C21H43N2O2þ ; calc. 355.3325).
(4S,5R,6S)-6-[(Dimethylamino)methyl]-5-hydroxy-4-[(E)-tridec-1-enyl)]piperidin-2-one (23).
Analogously to the preparation of 21, 37 (23.7 mg, 0.05 mmol) was transformed into 23 (16.2 mg,
92%). Colourless gum. Rf (CH2Cl2/MeOH 9 :1) 0.30. [a]2D5 ¼ ꢀ25.6 (c¼0.45, CHCl3). IR (ATR): 3301w
(br.), 3103w (sh), 2961m, 2922s, 2852m, 2774w, 1645s, 1459m, 1409w, 1320w, 1260s, 1182w, 1090s, 1021s,
971m, 848w, 799s, 721w. 1H-NMR (CDCl3, 300 MHz): 5.94 (s, NH); 5.67–5.54 (m, HꢀC(1’), HꢀC(2’));
4.19 (br. s, OH); 3.72 (dd, J¼8.1, 3.9, HꢀC(5)); 3.31 (q, Jꢃ7.5, HꢀC(6)); 2.74–2.71 (m, HꢀC(4)); 2.59
(dd, J¼12.0, 7.7, CHaꢀC(6)); 2.55–2.45 (m, 2 HꢀC(3)); 2.34 (dd, J¼12.1, 6.8, CHbꢀC(6)); 2.28 (s,
Me2N); 2.10–2.04 (m, 2 HꢀC(3’)); 1.38–1.32 (m, 2 HꢀC(4’)); 1.32–1.25 (m, 16 H); 0.88 (t, J¼6.7, Me).
13C-NMR (CDCl3, 75 MHz): 170.88 (s, C¼O); 134.59 (d, C(1’)); 126.42 (d, C(2’)); 72.49 (d, C(5)); 64.29

1710
CHEMISTRY & BIODIVERSITY – Vol. 6 (2009)
(t, CH2ꢀC(6)); 50.56 (d, C(6)); 45.89 (q, Me2N); 39.55 (d, C(4)); 34.17 (t, C(3)); 32.82, 31.93 (2t); 29.66–
29.20 (several t); 22.70 (t); 14.13 (q, Me). HR-MALDI-MS: 353.3164 (100, [M þ H]þ , C21H41N2O2þ ; calc.
353.3168).
(4S,5R,6S)-6-[(Dimethylamino)methyl]-5-hydroxy-4-(tridecyl)piperidin-2-one (24). Analogously to
the preparation of 22, 23 (13 mg, 0.037 mmol) was transformed into 24 (12.3 mg, 94%). Colourless gum.
Rf (CH2Cl2/MeOH 9 :1) 0.22. [a]2D5 ¼ ꢀ10.8 (c¼0.18, CHCl3). IR (ATR): 3360w, 3285w, 3180w, 3069w,
2953w, 2920s, 2852m, 2830w, 1658s, 1468m, 1401w, 1306w, 1260w, 1183w, 1088m, 1043w, 1024m, 885w,
1
840w, 720w. H-NMR (CDCl3, 300 MHz): 5.69 (s, NH); 3.79 (dd, J¼7.4, 3.6, HꢀC(5)); 3.39 (q, Jꢃ6.9,
HꢀC(6)); 2.54 (dd, J¼12.0, 8.7, CHaꢀC(6)); 2.47–2.35 (m, 2 HꢀC(3)); 2.36 (dd, J¼11.3, 5.5,
CHbꢀC(6)); 2.30 (s, Me2N); 1.93 (m, HꢀC(4)); 1.49–1.37 (m, 2 HꢀC(1’)); 1.39–1.19 (m, 22 H); 0.88 (t,
J¼6.7, Me). 13C-NMR (CDCl3, 75 MHz): 171.15 (s, C¼O); 72.91 (d, C(5)); 65.00 (t, CH2ꢀC(6)); 50.89
(d, C(6)); 46.00 (q, Me2N); 36.60 (d, C(4)); 33.89 (t, C(3)); 31.92 (t); 29.85–29.34 (several t); 27.46, 27.35,
22.70 (3t); 14.17 (q, Me). HR-MALDI-MS: 355.3320 (100, [M þ H]þ , C21H43N2O2þ ; calc. 355.3325).
(4R,5R,6S)-5-(Benzyloxy)-6-[(benzyloxy)methyl]-1-[(tert-butoxy)carbonyl]-4-[(E)-tridec-1-enyl]-
piperidin-2-one (40). A soln. of 31 (400 mg, 0.79 mmol) in MeCN (15 ml) was treated with Boc2O
(431.5 mg, 1.98 mmol) and 4-(dimethylamino)pyridine (145 mg, 1.19 mmol), stirred at 258 for 24 h,
treated with Boc2O (259 mg, 1.19 mmol) and 4-(dimethylamino)pyridine (48.3 mg, 0.4 mmol), and
stirred for 5 h. After evaporation of the solvent, FC (Et2O/hexane 5 :95!3 :7) gave 40 (383 mg, 80%).
Colourless gum. Rf (Et2O/hexane 3 :7) 0.22. [a]2D5 ¼ þ73.5 (c¼1.08, CHCl3). IR (ATR): 3034w, 2954w,
2923s, 2853m, 1774m, 1722s, 1454m, 1390w, 1367m, 1294s, 1253m, 1219m, 1154s, 1097s, 1028w, 967w, 852w,
772w, 734m, 697m. 1H-NMR (CDCl3, 400 MHz): 7.28–7.17 (m, 10 arom. H); 5.47 (dt, J ¼ 14.9, 7.2,
HꢀC(2’)); 5.24 (dd, J¼15.4, 7.4, HꢀC(1’)); 4.49, 4.45 (2d, J¼11.6, PhCH2); 4.41, 4.37 (2d, J¼12.0,
PhCH2); 4.36 (dt, J ¼ 5.3, 2.9, HꢀC(6)); 3.57 (dd, J ¼ 9.1, 2.6, HꢀC(5)); 3.47 (dd, J ¼ 9.6, 5.5,
CHaꢀC(6)); 3.41 (dd, J ¼ 9.6, 3.5, CHbꢀC(6)); 2.57–2.49 (m, HꢀC(4)); 2.36 (dd, J ¼ 17.2, 5.2,
HaꢀC(3)); 2.29 (dd, J ¼ 17.2, 12.4, HbꢀC(3)); 1.93 (q, J ¼ 6.9, 2 HꢀC(3’)); 1.42 (s, t-Bu); 1.29–1.18 (m,
18 H); 0.81 (t, J¼6.8, Me). 13C-NMR (CDCl3, 75 MHz): 172.04 (s, C(2)); 152.48 (s, C¼O); 137.92, 137.66
(2s); 132.78 (d, C(1’)); 129.36 (d, C(2’)); 128.45–127.67 (several d); 83.10 (d, C(5)); 79.42 (s, Me3C);
73.35, 72.08 (2t, 2 PhCH2); 71.30 (t, CH2ꢀC(6)); 60.28 (d, C(6)); 40.85 (d, C(4)); 37.60 (t, C(3)); 32.60,
31.93 (2t); 29.70–29.21 (several t); 28.03 (q, Me3C); 22.68 (t); 14.11 (q, Me). HR-MALDI-MS: 628.3982
(45, [M þ Na]þ , C38H55NNaO5þ ; calc. 628.3978), 506.3633 (100, [MꢀBocþ2 H]þ , C33H48NOþ3 ; calc.
506.3634). Anal. calc. for C38H55NO5 (605.86): C 75.33, H 9.15, N 2.31; found: C 75.28, H 9.16, N 2.41.
(3S,4S,5R,6S)-3-Allyl-5-(benzyloxy)-6-[(benzyloxy)methyl)]-1-[(tert-butoxy)carbonyl]-4-[(E)-tri-
dec-1-enyl]piperidin-2-one (41). A soln. of 40 (60 mg, 0.1 mmol) in THF (2 ml) was treated at ꢀ788 with
1m LiHMDS in toluene (130 ml, 0.13 mmol), allowed to warm to 08 within 4.5 h, and stirred at 258 for
30 min. The mixture was treated with HMPA (40 ml), cooled to ꢀ788, treated with a soln. of allyl bromide
(130 ml, 1.5 mmol) in THF (0.1 ml), warmed to 08 within 3.5 h, and stirred at 258 for 1 h. The mixture was
treated dropwise with sat. aq. NH4Cl soln. After dilution with CH2Cl2, the aq. phase was separated and
extracted with CH2Cl2 (3ꢂ50 ml). The combined org. phases were washed with brine, dried (Na2SO4),
and evaporated. FC (Et2O/pentane 1:9) gave 41 (45 mg, 70%). Colourless gum. Rf (AcOEt/pentane 1:9)
0.16. IR (ATR): 3070w, 3030w, 2975w, 2953w, 2923s, 2853m, 1770w, 1716s, 1639w, 1496w, 1454m, 1389w,
1367s, 1291s, 1254s, 1205m, 1153s, 1095s, 1068s, 1028w, 999m, 969m, 913m, 852w, 771w, 734s, 696s.
1H-NMR (CDCl3, 300 MHz; assignments based on a DQFCOSY spectrum): 7.35–7.24 (m, 10 arom. H);
5.82–5.72 (m, CH2¼CHCH2ꢀC(3)); 5.58 (dt, J ¼ 15.0, 6.9, HꢀC(2’)); 5.11 (ddt, J¼15.2, 9.0, 1.3,
HꢀC(1’)); 5.03–4.98 (m, CH2¼CHCH2ꢀC(3)); 4.52 (s, PhCH2); 4.49 (d, Jꢃ12.4, PhCH); 4.45 (d, Jꢃ
12.0, PhCH); 4.44–4.33 (m, HꢀC(6)); 3.67 (dd, J ¼ 8.1, 2.1, HꢀC(5)); 3.58 (dd, J ¼ 9.6, 5.5, CHaꢀC(6));
3.53–3.45 (dd of CHbꢀC(6) hidden by the solvent signal); 2.65–2.57 (m, CH2¼CHCHaꢀC(3)); 2.49 (q,
Jꢃ9.3, HꢀC(4)); 2.35–2.28 (m, HꢀC(3), CH2CHCHbꢀC(3)); 2.04 (br. q, Jꢃ7.1, 2 H ꢀC(3’)); 1.49 (s, t-
Bu); 1.38–1.24 (m, 18 H); 0.89 (t, J¼7.1, Me ) . 13C-NMR (CDCl3, 100 MHz; assignments based on a
HSQC spectrum): 173.71 (s, C(2)); 152.76 (s, C¼O); 138.02, 137.73 (2s); 135.16 (d, C(1’)); 134.76 (d,
CH¼CH2); 129.97 (d, C(2’)); 128.42–127.68 (several d); 117.21 (t, CH¼CH2); 82.85 (s, Me3C); 78.62 (d,
C(5)); 73.31, 71.98 (2t, 2 PhCH2); 70.69 (t, CH2ꢀC(6)); 59.43 (d, C(6)); 45.68 (d, C(4)); 44.32 (d, C(3));
32.65 (t); 32.16 (t, CH2CH¼CH2); 31.91 (t); 29.68–29.29 (several t); 28.02 (q, Me3C); 22.67, 22.32 (2t);

CHEMISTRY & BIODIVERSITY – Vol. 6 (2009)
1711
14.03 (q, Me). HR-MALDI-MS: 668.4283 (21, [M þ Na]þ , C41H59NNaO5þ ; calc. 668.4291), 546.3940
(100, [M ꢀ Bocþ2 H]þ , C36H52NOþ3 ; calc. 546.3947).
(3S,4S,5R,6S)-3-Allyl-5-(benzyloxy)-6-[(benzyloxy)methyl]-4-[(E)-tridec-1-enyl]piperidin-2-one
(42). An ice-cold soln. of 41 (30 mg, 0.046 mmol) in THF (1.5 ml) was treated with anisole (0.15 ml) and
CF3CO2H (0.3 ml), stirred at 258 for 15 h, and evaporated. A soln. of the residue in CH2Cl2 was washed
with sat. aq. NaHCO3 soln. (2ꢂ50 ml), dried (Na2SO4), and evaporated. The residue was filtered
through a short pad of silica gel (AcOEt/hexane 4 :6) to afford 42 (21.4 mg, 85%) that was used directly
for the next step. Colourless gum. Rf (AcOEt/hexane 3.5 :6.5) 0.27. IR (ATR): 3200w (br.), 3066w, 3030w,
2954w, 2923s, 2853m, 1666s, 1496w, 1454w, 1391w, 1364w, 1322w, 1208w, 1112m, 1073m, 1026w, 974w,
1
912w, 816w, 734m, 697m. H-NMR (CDCl3, 400 MHz): 7.39–7.18 (m, 10 arom. H); 6.07 (s, NH); 5.77–
5.59 (m, HꢀC(2’), CH2¼CHCH2ꢀC(3)); 5.17 (dd, J¼15.2, 9.1, HꢀC(1’)); 5.08–5.02 (m, CH¼CH2);
4.64, 4.34 (2d, J¼10.7, PhCH2); 4.49, 4.47 (2d, J¼12.0, PhCH2); 3.67 (dd, J ¼ 9.0, 2.8, CHaꢀC(6)); 3.54
(td, J ¼ 8.7, 2.7, HꢀC(6)); 3.33–3.24 (m, CHbꢀC(6), HꢀC(5)); 2.80 (td, J¼10.0, 4.3, HꢀC(3)); 2.60 (q,
J ¼ 9.9, HꢀC(4)); 2.32–2.22 (m, CH2ꢀC(3)); 2.07 (q, J ¼ 6.8, 2 HꢀC(3’)); 1.42–1.19 (m, 18 H); 0.88 (t,
J¼6.7, Me). 13C-NMR (CDCl3, 75 MHz): 171.74 (s, C(2)); 137.44, 137.24 (2s); 135.44 (d, CH¼CH2);
134.36 (d, C(1’)); 128.50 (d, C(2’)); 128.42–127.76 (several d); 117.92 (t, CH¼CH2); 76.91 (d, C(5)); 73.85,
73.22 (2t, 2 PhCH2); 70.65 (t, CH2ꢀC(6)); 56.01 (d, C(6)); 46.43 (d, C(4)); 43.71 (d, C(3)); 32.66 (t); 32.16
(t, CH2CH¼CH2); 31.81 (t); 29.57–29.23 (several t); 22.59 (t); 14.03 (q, Me). HR-MALDI-MS: 546.3935
(100, [M þ H]þ , C36H52NOþ3 ; calc. 546.3947).
(3S,4S,5R,6S)-5-Hydroxy-6-(hydroxymethyl)-3-propyl-4-(tridecyl)piperidin-2-one (43). An ice-cold
soln. of 42 (10 mg, 0.027 mmol) in MeOH (2.5 ml) was treated with AcOH (0.25 ml) and 10% Pd/C
(20 mg), and stirred under 8 bar of H2 for 24 h. The mixture was filtered through Celite (washing with
MeOH). The combined filtrate and washings were evaporated. FC (CH2Cl2/MeOH 1:0!9 :1) gave 43
(7.9 mg, 80%). Colourless gum. Rf (CH2Cl2/MeOH 9 :1) 0.32. [a]2D5 ¼ ꢀ19.7 (c¼0.21, CHCl3). IR (ATR):
3326w, 3287w (br.), 3160w (br.), 2956m, 2920s, 2851s, 1634s, 1484w, 1456w, 1436w, 1378w, 1356w, 1325w,
1304w, 1263w, 1235w, 1223w, 1149w, 1087m, 1069m, 1037w, 964w, 894w, 771m, 736m, 721w, 674w.
1H-NMR (CDCl3, 600 MHz): 7.03 (s, NH); 3.81 (br. s, OH); 3.75–3.70 (m, CH2ꢀC(6)); 3.43 (t, J ¼ 9.5,
HꢀC(5)); 3.16 (dt, J¼8.7, 4.2, HꢀC(6)); 2.86 (s, OH); 2.13 (dt, J¼9.1, 4.7, HꢀC(3)); 1.79–1.73 (m,
HaꢀC(1’)); 1.67 (tt, J¼9.5, 4.7, HꢀC(4)); 1.61–1.56 (m, HaꢀC(2’)); 1.54–1.49 (m, HbꢀC(1’)); 1.48–1.45
(m, 2 HꢀC(1’’)); 1.36–1.29 (m, HbꢀC(2’)); 1.25–1.17 (m, 24 H); 0.85 (t, J¼7.3, Me); 0.80 (t, J¼7.0, Me).
13C-NMR (CDCl3, 150 MHz): 174.89 (s, C(2)); 68.59 (d, C(5)); 61.36 (d, C(6)); 57.76 (t, CH2ꢀC(6));
43.05 (d, C(3)); 41.16 (d, C(4)); 31.68, 30.92 (2t, C(1’), C(1’’)); 29.24–28.68 (several t); 24.10, 21.68 (2t);
18.08 (t); 13.29, 13.09 (2q, 2 Me). HR-MALDI-MS: 370.3316 (100, [M þ H]þ , C22H44NO3þ ; calc.
370.3321).
(3S/R,4S,5R,6S)-5-(Benzyloxy)-6-[(benzyloxy)methyl]-3-[(E)-but-2-enyl]-1-[(tert-butoxy)carbon-
yl]-4-[(E)-tridec-1-enyl]piperidin-2-one (44a/44b). A soln. of 40 (80 mg, 0.13 mmol) in THF (2 ml) was
treated at ꢀ788 with 1m LiHMDS in toluene (170 ml, 0.17 mmol), allowed to warm to 08 within 4.5 h, and
stirred at 08 for 30. The mixture was treated with HMPA (50 ml), cooled to ꢀ788, treated with a soln. of
(E)-1-bromobut-2-ene (267 ml, 2.6 mmol) in THF (0.2 ml), warmed to 08 within 3.5 h, and stirred at 258
for 1 h. The mixture was treated dropwise with sat. aq. NH4Cl soln., and diluted with CH2Cl2. The phases
were separated, and the aq. phase was extracted with CH2Cl2 (3ꢂ50 ml). The combined org. phases were
washed with brine, dried (Na2SO4), and evaporated. FC (Et2O/hexane 17:3) gave 44a/44b 3 :1 (55 mg,
63%). Colourless gum. Rf (Et2O/hexane 17:3) 0.19. [a]2D5 ¼ þ61.2 (c¼1.0, CHCl3). IR (ATR): 3030w,
2954w, 2923s, 2853m, 1773w, 1715s, 1496w, 1454m, 1391w, 1367m, 1291s, 1255m, 1205m, 1154s, 1097s,
1
1069s, 1028w, 967m, 947w, 854w, 771w, 734s, 696s. H-NMR (CDCl3, 300 MHz; 44a/44b 3 :1): signals of
44a: 7.36–7.25 (m, 10 arom. H); 5.57 (dt, J ¼ 14.7, 7.2, HꢀC(2’)); 5.49–5.30 (m, CH¼CHMe); 5.11 (dd,
J¼15.4, 8.8, HꢀC(1’)); 4.52–4.47 (m, 2 PhCH2); 4.43–4.38 (m, HꢀC(6)); 3.66 (dd, J ¼ 8.5, 2.7,
HꢀC(5)); 3.58 (dd, J ¼ 9.6, 5.5, CHaꢀC(6)); 3.50 (dd, J ¼ 9.6, 3.5, CHbꢀC(6)); 2.59–2.19 (m, HꢀC(3),
HꢀC(4), CH2ꢀC(3)); 2.04 (q, J ¼ 6.4, 2 HꢀC(3’)); 1.61 (d, J¼4.6, CH¼CHMe); 1.50 (s, t-Bu); 1.37–
1.26 (m, 18 H); 0.88 (t, J¼6.5, Me); signals of 44b: 1.56 (d, J¼6.5, CH¼CHMe). 13C-NMR (CDCl3,
100 MHz; 44a/44b 3 :1): signals of 44a: 173.98 (s, C(2)); 152.81 (s, C¼O); 138.06, 137.78 (2s); 134.53 (d,
C(1’)); 129.12 (d, C(2’)); 127.91, 127.82 (2d, MeCH¼CHCH2ꢀC(3)); 127.72–127.33 (several d); 82.70
(Me3C); 78.61 (d, C(5)); 73.30, 72.03 (2t, 2 PhCH2); 70.68 (t, CH2ꢀC(6)); 59.44 (d, C(6)); 45.51 (d, C(4));

1712
CHEMISTRY & BIODIVERSITY – Vol. 6 (2009)
44.68 (d, C(3)); 32.67, 31.92 (2t); 29.69–29.29 (several t); 28.04 (q, Me3C); 22.68 (t); 18.02 (q,
CH¼CHMe); 14.10 (q, Me); signals of 44b: 173.87 (s, C(2)); 152.77 (s, C¼O); 137.75 (s); 129.20 (d,
C(2’)); 125.40 (d, CH¼CHMe); 82.79 (Me3C); 78.65 (d, C(5)); 71.94 (t, PhCH2); 70.66 (t, CH2ꢀC(6));
59.36 (d, C(6)); 46.09 (d, C(4)); 44.78 (d, C(3)); 32.70, 31.00 (2t); 25.63 (t); 13.10 (q, Me). HR-MALDI-
MS: 682.4456 (26, [M þ Na]þ , C42H61NNaO5þ ; calc. 682.4447), 560.4109 (100, [MꢀBocþ2 H]þ
,
C37H54NOþ3 ; calc. 560.4104).
(3S/R,4S,5R,6S)-5-(Benzyloxy)-6-[(benzyloxy)methyl]-3-[(E)-but-2-enyl]-4-[(E)-tridec-1-enyl]pi-
peridin-2-one (45a/45b). An ice-cold soln. of 44a/44b 3 :1 (60 mg, 0.09 mmol) in THF (4 ml) was treated
with anisole (0.25 ml, 2.3 mmol) and CF3CO2H (1 ml, 13.5 mmol), stirred at 258 for 24 h, and evaporated.
A soln. of the residue in CH2Cl2 was washed with sat. aq. NaHCO3 soln. (2ꢂ50 ml), dried (Na2SO4), and
evaporated. The residue was filtered through a short pad of silica gel (AcOEt/hexane 7:13) to afford
crude 45a/45b 3 :1 (44 mg, 86%) that was used directly for the next step. Colourless gum. Rf (AcOEt/
hexane 1:1) 0.29. IR (ATR): 3245w (br.), 3030w, 2923s, 2853m, 1663s, 1496w, 1454m, 1403w, 1363w,
1319w, 1208s, 1162s, 1095s, 1028m, 967s, 911w, 819w, 786w, 732s, 695s. 1H-NMR (CDCl3, 300 MHz; 45a/
45b 3 :1): signals of 45a: 7.57 (s, NH); 7.39–7.19 (m, 10 arom. H); 5.66 (dt, J ¼ 15.1, 6.9, HꢀC(2’)); 5.48
(dt, J ¼ 14.6, 7.0, CH¼CHMe); 5.31–5.24 (m, CH¼CHMe); 5.16 (br. dd, J¼15.2, 9.1, HꢀC(1’)); 4.65 (d,
J ¼ 10.6, PhCH); 4.55–4.47 (m, PhCH2); 4.36 (d, J ¼ 10.7, PhCH); 3.670 (dd, J ¼ 9.3, 2.4, CHaꢀC(6));
3.53 (ddd, J ¼ 9.0, 6.9, 2.4, HꢀC(6)); 3.43 (dd, J ¼ 9.3, 6.9, CHbꢀC(6)); 3.37 (dd, J ¼ 9.6, 9.0, HꢀC(5));
2.73–2.66 (m, HꢀC(3)); 2.60 (q, J ¼ 9.6, HꢀC(4)); 2.45–2.18 (m, CH2CH¼CHMe); 2.08 (br. q, J ¼ 6.8,
2 HꢀC(3’)); 1.65 (d, J¼6.3, CH¼CHMe); 1.44–1.20 (m, 18 H); 0.89 (t, J¼6.7, Me); signals of 45b: 3.663
(dd, J ¼ 9.3, 2.4, CHaꢀC(6)); 3.35 (dd, J ꢃ 9.3, 1.8, HꢀC(5)); 2.60 (q, J ¼ 9.3, HꢀC(4)); 1.60 (d, J¼6.8,
CH¼CHMe). 13C-NMR (CDCl3, 75 MHz; 45a/45b 3 :1): signals of 45a: 174.60 (s, C(2)); 137.33, 137.17
(2s); 133.73 (d, C(1’)); 129.25 (d, C(2’)); 128.39, 128.34 (2d); 128.25 (d, MeCH¼CHCH2ꢀC(3)); 128.02–
127.90 (several d); 125.79 (d, CH¼CHMe); 76.07 (d, C(5)); 74.12, 73.41 (2t, 2 PhCH2); 69.49 (t,
CH2ꢀC(6)); 56.46 (d, C(6)); 45.97 (d, C(4)); 43.89 (d, C(3)); 32.66, 31.82 (2t); 29.58–29.20 (several t);
22.59 (t); 17.97 (q, CH¼CHMe); 14.13 (q, Me); signals of 45b: 174.73 (s, C(2)); 127.06 (d, CH¼CHMe);
125.21 (d, CH¼CHMe); 74.08 (t, PhCH2); 69.44 (t, CH2ꢀC(6)); 46.50 (d, C(4)); 44.10 (d, C(3)); 32.69,
31.79 (2t); 25.43 (t); 13.15 (q, Me). HR-MALDI-MS: 560.4105 (100, [M þ H]þ , C39H60NO3þ ; calc.
560.4104).
(3S/R,4S,5R,6S)-3-[(E)-But-2-enyl]-5-hydroxy-6-(hydroxymethyl)-4-[(E)-tridec-1-enyl]piperidin-
2-one (46a/46b). An ice-cold soln. of 45a/45b 3 :1 (23 mg, 0.04 mmol) in 1,2-dichloroethane (1 ml) was
treated with anisole (88.8 mg, 0.82 mmol) and AlCl3 (54.8 mg, 0.41 mmol), stirred at 258 for 2 h, treated
dropwise with 1m HCl, and extracted with AcOEt (3ꢂ50 ml). The combined org. phases were washed
with brine, dried (Na2SO4), and evaporated. FC (CH2Cl2/MeOH 9 :1) afforded 46a/46b 3 :1 (12 mg,
78%). Complete removal of the minor isomer 46b was achieved by slow FC (CH2Cl2/MeOH 1:0!9 :1).
Data of 46a. Colourless gum. Rf (CH2Cl2/MeOH 9 :1) 0.42. [a]2D5 ¼ ꢀ18.3 (c¼0.16, CHCl3). IR
(ATR): 3298w (br.), 3254w, 3131w, 2957w, 2920s, 2852m, 1644s, 1492w, 1465w, 1431m, 1376w, 1311w,
1267w, 1103w, 1062m, 1033w, 967w, 954w, 790w, 747m. 1H-NMR (CDCl3 þ1 drop of CD3OD, 300 MHz):
5.63 (dt, J¼15.2, 6.8, HꢀC(2’)); 5.44 (dq, J¼14.4, 6.9, CH¼CHMe); 5.30–5.22 (m, CH¼CHMe); 5.03
(ddt, J¼15.2, 9.1, 1.3, HꢀC(1’); 3.83 (dd, J¼11.5, 3.3, CHaꢀC(6)); 3.54 (dd, J¼11.5, 6.3, CHbꢀC(6));
3.34 (dd, J¼10.2, 9.2, HꢀC(5)); 3.23 (ddd, J¼9.1, 6.2, 3.1, HꢀC(6)); 2.74–2.60 (m, HꢀC(3)); 2.33 (q,
J¼10.2, HꢀC(4)); 2.16 (dt, J¼11.0, 5.6, CH2ꢀC(3)); 2.05 (q, J¼6.8, 2 HꢀC(3’)); 1.62 (d, J¼6.3,
CH¼CHMe); 1.39–1.32 (m, 2 HꢀC(4’)); 1.29–1.16 (m, 16 H); 0.85 (t, J¼6.7, Me). 13C-NMR (CDCl3,
150 MHz): 172.85 (s, C(2)); 138.49 (d, C(1’)); 128.73 (d, C(2’)); 128.91 (d, CH¼CHMe); 126.49 (d,
CH¼CHMe); 68.53 (d, C(5)); 64.12 (t, CH2ꢀC(6)); 58.75 (d, C(6)); 47.62 (d, C(4)); 43.79 (d, C(3));
32.66, 31.94 (2t); 29.68–29.20 (several t); 22.72 (t); 18.10 (q, CH¼CHMe); 14.15 (q, Me). HR-MALDI-
MS: 380.3156 (100, [M þ H]þ , C23H42NO3þ ; calc. 380.3165).
Data of 46b. 1H-NMR (CDCl3, 500 MHz; 46a/46b 3 :1): 6.65 (s, NH); 5.83 (dt, J¼14.9, 6.8,
HꢀC(2’)); 5.76 (dq, J¼15.1, 6.9, CH¼CHMe); 5.59–5.52 (m, CH¼CHMe); 1.56 (d, J¼6.6,
CH¼CHMe). 13C-NMR (CDCl3, 125 MHz; 46a/46b 3 :1): 172.96 (s, C(2)); 128.13 (d, C(2’)); 126.63
(d, CH¼CHMe); 125.95 (d, CH¼CHMe); 68.48 (d, C(5)); 64.01 (t, CH2ꢀC(6)); 58.73 (d, C(6)); 48.13
(d, C(4)); 44.04 (d, C(3)); 18.08 (q, CH¼CHMe); 13.26 (q, Me).

CHEMISTRY & BIODIVERSITY – Vol. 6 (2009)
1713
(3S,4S,5R,6S)-3-Butyl-5-hydroxy-6-(hydroxymethyl)-4-(tridecyl)piperidin-2-one (47). An ice-cold
soln. of 45a/45b 3 :1 (23 mg, 0.04 mmol) in MeOH (5 ml) was treated with AcOH (0.5 ml) and 10% Pd/C
(50 mg), and stirred under 8 bar of H2 for 24 h. The mixture was filtered through Celite (washing with
AcOEt). The combined filtrate and washings were evaporated. FC (CH2Cl2/MeOH 1:0!9 :1) gave 47
(12 mg, 75%). Colourless gum. Rf (CH2Cl2/MeOH 9 :1) 0.37. [a]2D5 ¼ ꢀ26.2 (c¼0.41, CHCl3). IR (ATR):
3294w (br.), 3261w, 3156w (sh), 2953w, 2919s, 2852m, 1636s, 1484w, 1455w, 1439m, 1378w, 1324w, 1304w,
1220m, 1146w, 1068m, 1037w, 968w, 913w, 772s, 721w, 693w. 1H-NMR (CDCl3, 400 MHz): 7.30 (s, NH);
4.28 (t, J ¼ 5.0, CH2OH); 3.85–3.74 (m, CH2ꢀC(6)); 3.49 (td, Jꢃ9.7, 5.3, HꢀC(5)); 3.25 (d, J¼4.0,
HOꢀC(5)); 3.21 (dt, J¼8.8, 4.2, HꢀC(6)); 2.19 (dt, J ¼ 9.0, 4.7, HꢀC(3)); 1.89–1.80 (m, HꢀC(4));
1.77–1.70 (m, HaꢀC(1’)); 1.63–1.47 (m, HbꢀC(1’), CH2ꢀC(3)); 1.36–1.23 (m, 26 H); 0.89 (t, Jꢃ7.0,
2 Me). 13C-NMR (CDCl3, 100 MHz): 176.26 (s, C(2)); 69.24 (d, C(5)); 61.75 (t, CH2ꢀC(6)); 58.88 (d,
C(6)); 44.34 (d, C(3)); 42.05 (d, C(4)); 31.94, 30.55 (2t); 30.36, 30.22 (2t); 29.73–29.37 (several t); 27.94,
25.26 (2t); 22.93, 22.69 (2t); 14.10, 13.98 (2q, 2 Me). HR-MALDI-MS: 384.3470 (100, [M þ H]þ
,
C23H46NOþ3 ; calc. 384.3478).
(4S,5R,6S)-5-(Benzyloxy)-6-[(benzyloxy)methyl]-1-[(tert-butoxy)carbonyl]-4-[(E)-tridec-1-enyl]-
piperidin-2-one (48). Analogously to the preparation of 40, 32 (260 mg, 0.51 mmol) gave 48 (256 mg,
83%). Colourless gum. Rf (Et2O/hexane 1:4) 0.17. [a]2D5 ¼ þ38.5 (c¼1.0, CHCl3). IR (ATR): 3034w,
2954w, 2923s, 2853m, 1771m, 1714s, 1496w, 1454m, 1389w, 1367m, 1295s, 1244s, 1206m, 1152s, 1094s,
1
1067s, 1027m, 969m, 937w, 911w, 853w, 804w, 780w, 733s, 696s. H-NMR (CDCl3, 300 MHz): 7.37–7.26
(m, 10 arom. H); 5.52–5.39 (m, HꢀC(1’), HꢀC(2’)); 4.62, 4.46 (2d, J¼12.0, PhCH2); 4.57–4.51 (m,
HꢀC(6), PhCH2); 3.81 (t, J¼2.4, HꢀC(5)); 3.58 (dd, J ¼ 9.8, 4.0, CHaꢀC(6)); 3.47 (dd, J ¼ 9.7, 7.8,
CHbꢀC(6)); 2.81–2.74 (m, HꢀC(4)); 2.68 (dd, J ¼ 16.2, 11.6, HaꢀC(3)); 2.40 (dd, J ¼ 16.2, 5.2,
HbꢀC(3)); 2.04–1.96 (m, 2 HꢀC(3’)); 1.49 (s, t-Bu); 1.36–1.27 (m, 18 H); 0.89 (t, J¼6.7, Me). 13C-NMR
(CDCl3, 75 MHz): 170.87 (s, C(2)); 152.73 (s, C¼O); 137.98, 137.58 (2s); 132.37 (d, C(1’)); 128.90 (d,
C(2’)); 128.36–127.55 (several d); 82.92 (s, Me3C); 75.45 (d, C(5)); 73.17, 71.36 (2t, 2 PhCH2); 69.49 (t,
CH2ꢀC(6)); 56.97 (d, C(6)); 36.88 (d, C(4)); 36.14 (t, C(3)); 32.45, 31.82 (2t); 29.61–29.09 (several t);
27.86 (q, Me3C); 22.59 (t); 14.03 (q, Me). HR-MALDI-MS: 628.3980 (46, [M þ Na]þ , C38H55NNaO5þ ;
calc. 628.3978), 506.3631 (100, [M ꢀ Bocþ2 H]þ , C33H48NO3þ ; calc. 506.3634). Anal. calc. for C38H55NO5
(605.86): C 75.33, H 9.15, N 2.31; found: C 75.37, H 9.17, N 2.33.
(3R/S,4R,5R,6S)-5-(Benzyloxy)-6-[(benzyloxy)methyl]-3-[(E)-but-2-enyl]-1-[(tert-(butoxy)car-
bonyl]-4-[(E)-tridec-1-enyl]piperidin-2-one (49a/49b). Analogously to the preparation of 44a/44b, 48
(75 mg, 0.12 mmol) gave 49a/49b 3 :1 (65 mg, 60%). Colourless gum. Rf (Et2O/hexane 1:4) 0.22. [a]D25
¼
þ22.9 (c¼0.85 CHCl3). IR (ATR): 3062w, 3030w, 2953w, 2923s, 2853m, 1770w, 1715s, 1496w, 1454m,
1391w, 1367m, 1292s, 1251m, 1205m, 1155s, 1112s, 1069s, 1028w, 970m, 945w, 854w, 818w, 733s, 697s.
1H-NMR (CDCl3, 400 MHz; 49a/49b 3 :1): signals of 49a: 7.29–7.18 (m, 10 arom. H); 5.39–5.28 (m,
HꢀC(2’), CH¼CHMe); 5.23–5.12 (m, HꢀC(1’)); 4.55 (d, J ¼ 11.9, PhCH); 4.49 (dt, J ¼ 8.3, 3.2,
HꢀC(6)); 4.45 (d, J ¼ 12.2, PhCH); 4.42 (d, J ¼ 12.0, PhCH); 4.37 (d, J ¼ 12.2, PhCH); 3.72 (br. t, J ꢃ
2.4, HꢀC(5)); 3.47 (dd, J ¼ 9.7, 4.6, CHaꢀC(6)); 3.32 (dd, J ¼ 9.7, 8.4, CHbꢀC(6)); 2.65–2.58 (m,
HꢀC(3)); 2.55 (m, HꢀC(4), CHaCH¼CHMe); 2.05–1.99 (m, CHbCH¼CHMe); 1.97–1.91 (m,
2 HꢀC(3’)); 1.48 (d, J¼6.3, CH¼CHMe); 1.42 (s, t-Bu); 1.30–1.19 (m, 18 H); 0.81 (t, J¼6.9, Me);
signals of 49b: 5.50 (dq, J¼14.5, 7.1, CH¼CHMe); 5.04 (ddt, J¼15.2, 9.0, 1.3, HꢀC(1’)); 4.56 (d, J ¼ 11.9,
PhCH); 3.48 (dd, J ¼ 9.8, 4.6, CHaꢀC(6)); 3.34 (dd, J ¼ 10.3, 8.4, CHbꢀC(6)); 2.23–2.14 (m,
CHaCH¼CHMe); 2.05–1.99 (m, CHbCH¼CHMe); 1.45 (d, J¼6.3, CH¼CHMe); 1.41 (s, t-Bu).
13C-NMR (CDCl3, 100 MHz; 49a/49b 3 :1): signals of 49a: 173.09 (br. s, C(2)); 153.34 (s, C¼O); 138.24,
137.82 (2s); 133.62 (d, C(1’)); 129.40 (d, C(2’)); 127.80, 127.19 (2d, CH¼CHMe); 128.46–127.59 (several
d); 82.81 (s, Me3C); 76.22 (d, C(5)); 73.22 (t, PhCH2); 71.50 (br. t, PhCH2); 69.66 (br. t, CH2ꢀC(6)); 56.23
(br. d, C(6)); 44.34 (d, C(4)); 40.62 (d, C(3)); 32.55, 31.94 (2t); 29.71–29.21 (several t); 28.00 (q, Me3C);
22.70 (t); 17.93 (q, CH¼CHMe); 14.11 (q, Me); signals of 49b: 173.11 (s, C(2)); 153.38 (s, C¼O); 138.22,
137.76 (2s); 133.58 (d, C(1’)); 129.60 (d, C(2’)); 126.54, 126.14 (2d, CH¼CHMe); 128.44–127.75 (several
d); 82.84 (Me3C); 76.31 (d, C(5)); 73.31 (t, PhCH2); 44.40 (d, C(4)); 41.07 (d, C(3)); 32.58, 31.15 (2t);
28.05 (q, CH¼CHMe); 22.66 (t); 13.16 (q, Me). HR-MALDI-MS: 682.4440 (34, [M þ Na]þ
,
C42H61NNaOþ5 ; calc. 682.4447), 560.4098 (100, [MꢀBocþ2 H]þ , C37H54NOþ3 ; calc. 560.4104).

1714
CHEMISTRY & BIODIVERSITY – Vol. 6 (2009)
(3R/S,4R,5R,6S)-5-(Benzyloxy)-6-[(benzyloxy)methyl]-3-[(E)-but-2-enyl]-4-[(E)-tridec-1-enyl]pi-
peridin-2-one (50a/50b 3 :1). Analogously to the preparation of 45a/45b, 49a/49b (55 mg, 0.083 mmol)
gave 50a/50b 3 :1 (37 mg, 80%). Colourless gum. Rf (AcOEt/hexane 7:13) 0.20. IR (ATR): 3290w,
3208w, 3087w, 3066w, 3030w, 2953m, 2922s, 2853s, 1660s, 1496w, 1454m, 1407w, 1360w, 1336w, 1308w,
1253w, 1206m, 1162s, 1098s, 1069s, 1027w, 969s, 911w, 816w, 786w, 733s, 696s. 1H-NMR (CDCl3, 600 MHz;
50a/50b 3 :1): signals of 50a: 7.35–7.25 (m, 10 arom. H); 6.82 (s, NH); 5.48–5.47 (m, HꢀC(2’),
CH¼CHMe); 5.41 (br. ddt, J¼15.2, 6.4, 1.1, HꢀC(1’)); 5.27 (dtq, J¼15.0, 7.4, 1.5, CH¼CHMe); 4.52,
4.47 (2d, J ¼ 11.9, PhCH2); 4.50, 4.48 (2d, J ¼ 12.0, PhCH2); 3.71–3.66 (m, HꢀC(6)); 3.60 (dd, J ¼ 5.3,
3.1, HꢀC(5)); 3.52 (dd, J ¼ 9.3, 4.7, CHaꢀC(6)); 3.32 (dd, J ¼ 9.3, 7.4, CHbꢀC(6)); 2.63–2.26 (several m,
HꢀC(3), HꢀC(4), CH2CH¼CHMe); 2.03–1.97 (m, 2 HꢀC(3’)); 1.61 (br. dd, J¼6.4, 1.4, CH¼CHMe);
1.37–1.30 (m, 2 HꢀC(4’)); 1.29–1.21 (m, 16 H); 0.86 (t, J¼7.0, Me); signals of 50b: 6.88 (s, NH); 5.53–
5.49 (m, HꢀC(2’), CH¼CHMe); 5.24–5.20 (m, CH¼CHMe); 3.61 (dd, J¼4.8, 3.1, HꢀC(5)); 3.51 (dd,
J ¼ 9.3, 4.9, CHaꢀC(6)); 3.36 (dd, J ¼ 9.3, 7.3, CHbꢀC(6)); 1.56 (dd, J¼6.8, 1.7, CH¼CHMe). 13C-NMR
(CDCl3, 150 MHz; 50a/50b 3 :1): signals of 50a: 174.78 (s, C(2)); 137.74 (br. s); 137.50 (s); 133.94 (d,
C(1’)); 128.49 (d, C(2’)); 128.50–127.70 (several d); 127.66, 127.31 (2d, CH¼CHMe); 73.75 (d, C(5));
73.45, 71.39 (2t, 2 PhCH2); 71.28 (t, CH2ꢀC(6)); 53.82 (d, C(6)); 42.35 (d, C(4)); 38.94 (d, C(3)); 32.71,
31.93 (2t); 29.69–29.20 (several t); 22.69 (t); 17.92 (q, CH¼CHMe); 14.11 (q, Me); signals of 50b: 174.79
(s, C(2)); 137.49 (s); 133.91 (d, C(1’)); 127.84 (d, C(2’)); 126.55, 126.54 (2d, CH¼CHMe); 74.26 (d, C(5));
73.43 (t, PhCH2); 71.37, 71.35 (2t, PhCH2, CH2ꢀC(6)); 53.89 (d, C(6)); 42.31 (d, C(4)); 39.55 (d, C(3));
32.68 (t); 26.85 (t); 13.18 (q, Me). HR-MALDI-MS: 560.4100 (100, [M þ H]þ , C39H60NO3þ ; calc.
560.4104).
(3R/S,4R,5R,6S)-3-[(E)-But-2-enyl]-5-hydroxy-6-(hydroxymethyl)-4-[(E)-tridec-1-enyl]piperidin-
2-one (51a/51b 3 :1). Analogously to the preparation of 46a/46b, 50a/50b (18 mg, 0.032 mmol) gave 51a/
51b 3 :1 (9.3 mg, 76%). Colourless gum. Rf (CH2Cl2/MeOH 9 :1) 0.41. [a]2D5 ¼ ꢀ1.5 (c¼0.14, CHCl3). IR
(ATR): 3311w (br.), 3131w, 2957w, 2923s, 2853m, 1634s, 1466w, 1433w, 1374w, 1342w, 1261w, 1219w,
1150w, 1081w, 1024w, 969w, 772s, 721w. 1H-NMR (CD3OD, 600 MHz; 51a/51b 3 :1): signals of 51a: 5.58–
5.53 (m, HꢀC(1’), CH¼CHMe); 5.56 (dt, J¼14.5, 7.3, HꢀC(2’)); 5.34 (dtq, J¼15.0, 7.0, 1.5,
CH¼CHMe); 3.95 (t, J¼3.2, HꢀC(5)); 3.54 (d, J¼6.3, CH2ꢀC(6)); 3.36 (td, J¼6.3, 3.8, HꢀC(6));
2.59 (dtd, J¼13.8, 6.0, 1.2, CHaCH¼CHMe); 2.56 (td, J¼8.4, 2.6, HꢀC(4)); 2.42 (ddd, J¼8.9, 6.0, 4.2,
HꢀC(3)); 2.24 (ddd, J¼13.5, 8.6, 4.6, CHbCH¼CHMe); 2.11–2.07 (m, 2 HꢀC(3’)); 1.68 (br. dd, J¼6.4,
0.8, CH¼CHMe); 1.44–1.40 (m, 2 HꢀC(4’)); 1.36–1.31 (m, 16 H); 0.92 (t, J¼7.0, Me); signals of 51b:
5.32–5.28 (m, HꢀC(1’)); 3.96 (br. dd, J¼3.6, 2.1, HꢀC(5)); 3.55 (d, J¼6.0, CH2ꢀC(6)); 3.38 (td, J¼6.5,
3.8, HꢀC(6)); 2.52–2.48 (m, 2 H); 2.42–2.38 (m, 1 H); 1.64 (d, J¼6.8, CH¼CHMe). 13C-NMR (CDCl3,
150 MHz; 51a/51b 3 :1): signals of 51a: 174.53 (br. s, C(2)); 135.93 (d, C(1’)); 128.51 (d, C(2’)); 127.37 (d,
CH¼CHMe); 126.93 (d, CH¼CHMe); 65.99 (d, C(5)); 64.20 (t, CH2ꢀC(6)); 58.34 (d, C(6)); 43.10, 42.24
(2d, C(3), C(4)); 32.73, 31.92 (2t); 29.68–29.26 (several t); 22.69 (t); 17.97 (q, CH¼CHMe); 14.12 (q,
Me); signals of 51b: 135.80 (d, C(1’)); 126.78 (d, CH¼CHMe); 126.67 (d, CH¼CHMe); 66.41 (d, C(5));
64.27 (t, CH2ꢀC(6)); 58.52 (d, C(6)); 42.52 (d, C(3) or C(4)); 33.32 (t); 13.13 (q, Me). HR-MALDI-MS:
380.3158 (100, [M þ H]þ , C23H42NO3þ ; calc. 380.3165).
(3R,4R,5R,6S)-3-Butyl-5-hydroxy-6-(hydroxymethyl)-4-(tridecyl)piperidin-2-one (52). Analogously
to the preparation of 47, 50a/50b 3 :1 (9 mg, 0.016 mmol) gave 52 (4.5 mg, 74%). Colourless gum. Rf
(CH2Cl2/MeOH 9 :1) 0.36. [a]2D5 ¼ ꢀ24.3 (c¼0.23, CHCl3). IR (ATR): 3307w (br.), 2957w, 2922s, 2853s,
1638s, 1465m, 1417w, 1378w, 1342w, 1314w, 1261w, 1223w, 1156w, 1075m, 1037w, 968w, 769s, 721w.
1H-NMR (CD3OD, 300 MHz): 4.01 (dd, J ¼ 6.0, 3.2, irrad. at 1.80!d, J ¼ 5.9, HꢀC(5)); 3.62 (dd, J ¼
11.2, 5.2, CHaꢀC(6)); 3.53 (dd, J ¼ 11.2, 5.6, CHbꢀC(6)); 3.35–3.32 (m, HꢀC(6)); 2.27 (q, J ¼ 5.8, irrad.
at 1.80!t, J ¼ 5.1, HꢀC(3)); 1.80 (qd, J ¼ 6.4, 3.2, irrad. at 4.01!q, J ¼ 6.5, HꢀC(4)); 1.68 (td, J ¼ 13.7,
6.5, 2 HꢀC(1’)); 1.39–1.21 (m, 28 H); 0.92 (t, Jꢃ6.9, Me); 0.89 (t, Jꢃ7.2, Me). 13C-NMR (CDCl3,
150 MHz): 175.57 (s, C(2)); 65.30 (d, C(5)); 64.26 (t, CH2ꢀC(6)); 57.09 (d, C(6)); 43.97 (d, C(3)); 39.63
(d, C(4)); 31.94, 30.85 (2t); 29.83–29.37 (several t); 27.33, 27.18 (2t); 22.70, 22.68 (2t); 14.12, 13.98 (2q,
2 Me). HR-MALDI-MS: 384.3465 (100, [M þ H]þ , C23H46NO3þ ; calc. 384.3478).

CHEMISTRY & BIODIVERSITY – Vol. 6 (2009)
REFERENCES
1715
[1] D. M. Pawar, A. A. Khalil, D. R. Hooks, K. Collins, T. Elliott, J. Stafford, L. Smith, E. A. Noe, J. Am.
Chem. Soc. 1998, 120, 2108.
[2] C. H. Langley, D. M. Pawar, E. A. Noe, THEOCHEM 2005, 732, 99.
[3] M. Koch, V. S. Stronge, D. Shepherd, S. D. Gadola, B. Mathew, G. Ritter, A. R. Fersht, G. S. Besra,
R. R. Schmidt, E. Y. Jones, V. Cerundolo, Nat. Immunol. 2005, 6, 819.
[4] L. M. Leoni, H. C. Shih, L. Deng, C. Tuey, G. Walter, D. A. Carson, H. B. Cottam, Biochem.
Pharmacol. 1998, 55, 1105.
[5] M. Macchia, S. Barontini, S. Bertini, V. Di Bussolo, S. Fogli, E. Giovannetti, E. Grossi, F. Minutolo,
R. Danesi, J. Med. Chem. 2001, 44, 3994.
[6] S. Brodesser, P. Sawatzki, T. Kolter, Eur. J. Org. Chem. 2003, 2021.
[7] J.-H. Jang, K. Kanoh, K. Adachi, Y. Shizuri, J. Nat. Prod. 2006, 69, 1358.
[8] B. Malewicz, J. T. Valiyaveettil, K. Jacob, H.-S. Byun, P. Mattjus, W. J. Baumann, R. Bittman, R. E.
Brown, Biophys. J. 2005, 88, 2670.
[9] S. Spiegel, S. Milstien, J. Biol. Chem. 2007, 282, 2125.
[10] K. Thevissen, I. E. J. A. FranÅois, J. Winderickx, C. Pannecouque, B. P. A. Cammue, Mini-Rev. Med.
Chem. 2006, 6, 699.
[11] T. Baumruker, E. E. Prieschl, Semin. Immunol. 2002, 14, 57.
[12] J. R. Casimir, C. Didierjean, A. Aubry, M. Rodriguez, J.-P. Briand, G. Guichard, Org. Lett. 2000, 2,
895.
[13] L. Battistini, G. Rassu, L. Pinna, F. Zanardi, G. Casiraghi, Tetrahedron: Asymmetry 1999, 10, 765.
[14] R. Rajan, K. Wallimann, A. Vasella, D. Pace, A. A. Genazzani, P. L. Canonico, F. Condorelli, Chem.
Biodiversity 2004, 1, 1785.
[15] A. E. Wick, K. Steen, D. Felix, A. Eschenmoser, Helv. Chim. Acta 1964, 47, 2425.
[16] M. Scholl, S. Ding, C. W. Lee, R. H. Grubbs, Org. Lett. 1999, 1, 953.
[17] A. Bielawska, H. M. Crane, D. Liotta, L. M. Obeid, Y. A. Hannun, J. Biol. Chem. 1993, 268, 26226.
[18] J. M. Kraveka, L. Li, Z. M. Szulc, J. Bielawski, B. Ogretmen, Y. A. Hannun, L. M. Obeid, A.
Bielawska, J. Biol. Chem. 2007, 282, 16718.
[19] J. Stiban, D. Fistere, M. Colombini, Apoptosis 2006, 11, 773.
[20] W. Zheng, J. Kollmeyer, H. Symolon, A. Momin, E. Munter, E. Wang, S. Kelly, J. C. Allegood, Y.
Liu, Q. Peng, H. Ramaraju, M. C. Sullards, M. Cabot, A. H. Merrill Jr., Biochim. Biophys. Acta,
Biomembr. 2006, 1758, 1864.
[21] Q. Jiang, J. Wong, H. Fyrst, J. D. Saba, B. N. Ames, Proc. Natl. Acad. Sci. U.S.A. 2004, 101, 17825.
[22] D. Camp, I. D. Jenkins, Aust. J. Chem. 1988, 41, 1835.
[23] E. F. V. Scriven, K. Turnbull, Chem. Rev. 1988, 88, 297.
´
[24] B. I. Glꢄnzer, Z. Gyçrgydeak, B. Bernet, A. Vasella, Helv. Chim. Acta 1991, 74, 343.
[25] A. Billich, P. Ettmayer, Anal. Biochem. 2004, 326, 114.
´
[26] P. Rovina, M. Jaritz, S. Hçfinger, C. Graf, P. Devay, A. Billich, T. Baumruker, F. Bornancin,
Biochem. J. 2006, 400, 255.
[27] A. Shamshiev, H.-J. Gober, A. Donda, Z. Mazorra, L. Mori, G. De Libero, J. Exp. Med. 2002, 195,
1013.
[28] H. Gallati, I. Pracht, J. Schmidt, P. Hꢄring, G. Garotta, J. Biol. Regul. Homeost. Agents 1987, 1, 109.
[29] D. M. Zajonc, I. A. Wilson, Curr. Top. Microbiol. Immunol. 2007, 314, 27.
[30] N. A. Borg, K. S. Wun, L. Kjer-Nielsen, M. C. Wilce, D. G. Pellicci, R. Koh, G. S. Besra, M.
Bharadwaj, D. I. Godfrey, J. McCluskey, J. Rossjohn, Nature 2007, 448, 44.
[31] K. S. Wun, N. A. Borg, L. Kjer-Nielsen, T. Beddoe, R. Koh, S. K. Richardson, M. Thakur, A. R.
Howell, J. P. Scott-Browne, L. Gapin, D. I. Godfrey, J. McCluskey, J. Rossjohn, J. Exp. Med. 2008,
205, 939.
Received February 24, 2009