An efficient approach to the synthesis of enantiomerically pure trans-1-amino-2-(hydroxymethyl)cyclopropanephosphonic acids

Article abstract of DOI:10.1016/j.tetasy.2010.07.017

The synthesis of (1R,2S)- and (1S,2R)-1-amino-2-(hydroxymethyl) cyclopropanephosphonic acids was accomplished using different strategies. The (1R,2S)-stereoisomer could be efficiently obtained by the cyclopropanation of ethyl diethoxyphosphorylacetate with the cyclic sulfate derived from (S)-3-benzyloxy-1,2-propandiol as a key step. The (1S,2R)-stereoisomer was synthesized from a readily available (1S,5R)-3-oxabicyclo[3.1.0]hexan-2-on-1- phosphonate.

Full text of DOI:10.1016/j.tetasy.2010.07.017

Tetrahedron: Asymmetry 21 (2010) 2081–2086
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Tetrahedron: Asymmetry
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An efficient approach to the synthesis of enantiomerically pure
trans-1-amino-2-(hydroxymethyl)cyclopropanephosphonic acids
*
Katarzyna Wa˛sek, Jacek Ke˛dzia, Henryk Krawczyk
_
´
Institute of Organic Chemistry, Technical University (Politechnika), 90-924 Łódz, Zeromskiego 116, Poland
a r t i c l e i n f o
a b s t r a c t
Article history:
The synthesis of (1R,2S)- and (1S,2R)-1-amino-2-(hydroxymethyl)cyclopropanephosphonic acids was
accomplished using different strategies. The (1R,2S)-stereoisomer could be efficiently obtained by the
cyclopropanation of ethyl diethoxyphosphorylacetate with the cyclic sulfate derived from (S)-3-benzyl-
oxy-1,2-propandiol as a key step. The (1S,2R)-stereoisomer was synthesized from a readily available
(1S,5R)-3-oxabicyclo[3.1.0]hexan-2-on-1-phosphonate.
Received 20 May 2010
Accepted 13 July 2010
Available online 10 August 2010
Ó 2010 Elsevier Ltd. All rights reserved.
1. Introduction
interested in the preparation of both enantiopure trans-1-amino-
2-(hydroxymethyl)cyclopropanephosphonic acids (1R,2S)-10 and
Configurationally homogeneneous
a
-aminophosphonic acids
(1S,2R)-10. These compounds are isosters of transition states in
various carbonyl group transformations of conformationally re-
stricted methanohomoserines, and can be taken into consideration
as potential models for some enzymatic reactions as well as com-
ponents of enzyme inhibitors.6
are an important class of compounds that have numerous funda-
mental and practical applications.1 Several selective methods for
their synthesis have been reported.2 However, the literature
contains only two approaches to individual non-racemic a-amino-
cyclopropanephosphonic acids. The synthesis of trans-(1R,2R)-1-
amino-2-methylcyclopropane phosphonic acid as an isostere of
(1R,2R)-allo-norcoronamic acid was successfully performed using
(S)-1,2-propanediol as the starting material.3 Regioselective ring
opening of the cyclic sulfate of this diol with sodium t-butyl dim-
ethoxyphosphorylacetate followed by SN2 intramolecular displace-
ment of the sulfate group in the resulting intermediate gave
dimethyl trans-(1R,2R)-1-t-butoxycarbonyl-2-methylcyclopropane-
phosphonate. This ester was subsequently converted into the corre-
sponding azide, which upon stereoselective Curtius rearrangement
afforded the enantiopure target compound. An alternative strategy
was employed for the preparation of trans-(1R,2R)-1-amino-2-
methylcyclopropanephosphonic acid.4 The first and crucial step of
this approach involved the addition of trimethyl phosphite to an
We envisaged that the enantiopure cyclopropanephosphonic
acids (1R,2S)-10 and (1S,2R)-10 might be conveniently prepared
from the properly protected enantiomeric 1-diethoxyphosphoryl-
2-(hydroxymethyl) cyclopropanecarboxylic acids following the
procedure reported for the preparation of the phosphonic analogue
of allo-norcoronamic acid.
This also implied that the suitable precursors of the acids 10
would be the known 3-benzyloxy-1,2-propanediols with (2R)-
and (2S)-stereochemistry.7,8 The particularly attractive starting
material seemed to be the cyclic sulfate (S)-1, readily accessible
from D
-mannitol.8
On the other hand, we anticipated that an equally attractive syn-
thesis of the aminophosphonic acids (1S,2R)-10 and (1R,2S)-10
could be based on enantiomerically pure 3-oxabicyclo[3.1.0]hex-
an-2-on-1-phosphonates (1S,5R)-6 and (1R,5S)-6 as the starting
materials. We believed that these phosphonates would be accessible
iminium salt derived from (S)-2-methylcyclopropanone and (S)-a-
phenylethylamine, which gave diethyl (1S,2S)-1-amino-2-meth-
ylcyclopropanephosphonate as the major diastereoisomer (de
74%). The next steps relied on the sequential deprotection of the
amino group and the phosphonic acid residue of the phosphonate
obtained.
by aminolysis of the corresponding racemate 69 with enantiopure
a-
phenylethylamine followed by resolution, hydrolysis and lactoniza-
tion of the diastereoisomeric amides (1S,2R)-13 and (1R,2S)-13. It
was expected that the
c-lactone ring opening in the bicyclic
Carrying on our recent studies on new stereocontrolled cyclo-
propanation reactions and the synthesis of nonracemic cyclopro-
panes bearing electron-withdrawing substituents,5 we became
phosphonates (1S,5R)-6 and (1R,5S)-6 with ammonia would provide
simple (1S,2R)- and (1R,2S)-1-diethoxyphosphoryl-2-(hydroxy-
methyl)cyclopropanecarboxyamides. After blocking the hydroxy-
methylene group with an acyl moiety, transformation into the
respective aminophosphonic acids (1S,2R)-10 and (1R,2S)-10 could
be accomplished by Hoffmann rearrangement, subsequent depro-
tection and dealkylation of the phosphonate functionality.
* Corresponding author. Tel.: +48 42 631 31 04; fax: +48 42 636 55 30.
E-mail address: henkrawc@p.lodz.pl (H. Krawczyk).
0957-4166/$ - see front matter Ó 2010 Elsevier Ltd. All rights reserved.
doi:10.1016/j.tetasy.2010.07.017

2082
K. Wa˛sek et al. / Tetrahedron: Asymmetry 21 (2010) 2081–2086
BnO
CO2H
BnO
N C O
2. Results and discussion
a
P(OEt)2
O
(1R,2S)-4
P(OEt)2
O
(1R,2S)-7
The (S)-(ꢀ)-4-benzyloxymethyl-2,2-dioxo-1,3,2-dioxolane
1
used in this study was obtained according to a literature proce-
dure.8 Treatment of the sulfate (S)-1 with ethyl diethoxyphosph-
orylacetate 2 in the presence of 2 equiv of NaH at reflux for 8 h
provided the corresponding cyclopropanecarboxylate 3 as a single
diastereoisomer in 62% yield (Scheme 1).
BnO
NHCO2Et
c
b
P(OEt)2
O
(1R,2S)-8
(EtO)2P
CO2Et
HO
NHCO2Et
HO
NH2
BnO
CO2Et
O
2
d, e
a
O
P(OEt)2
O
P(OH)2
O
S
O
P(OEt)2
O
O
BnO
(1R,2S)-9
(+)-(1R,2S)-10
(-)-(S)-1
(1R,2S)-3
Scheme 2. Reagents and conditions: (a) DPPA (1.1 equiv), Et3N (1.2 equiv), toluene,
reflux, 1 h; (b) EtOH (1.5 equiv), benzene, reflux, 1.5 h, 75%; (c) 10% Pd/C, H2, EtOH,
rt, 2 h, 95%; (d) Me3SiBr (5 equiv), DCM, reflux, 3 h; (e) propylene oxide (17 equiv),
EtOH, rt, 2 h, 95%.
BnO
CO2H
c
b
P(OEt)2
O
(1R,2S)-4
O
O
O
P(OEt)2
BnO
COCl
Br
11
a
P(OEt)2
(EtO)2P
CO2Et
P(OEt)2
O
O
2
O
O
O
(1R,2S)-5
(-)-(1R,5S)-6
6
H2N
Me
(R)-12
H
Scheme 1. Reagents and conditions: (a) 2 (1 equiv), NaH (2 equiv), THF, reflux, 8 h,
62%; (b) NaOH (1.5 equiv), EtOH/H2O, rt, 48 h, 97%; (c) (COCl)2 (2 equiv), DCM,
reflux, 4 h, 90%.
Ph b, c
However, the relative configuration of this diastereoisomer
could not be directly confirmed by spectroscopic methods. Con-
versely, subsequent hydrolysis of the cyclopropanation product 3
afforded the cyclopropanecarboxylic acid 4 whose 1H NMR spec-
Ph
H
Me
Ph
HO
CONH
HO
CONH
H
Me
P(OEt)2
O
P(OEt)2
O
3
trum showed the coupling constant JHP = 16.5 Hz corresponding
to a synperiplanar geometry of the phosphoryl residue and H-2
atom.3,10 Such an arrangement allowed us to assign the (1R,2S)-
stereochemistry to both the acid 4 and its precursor 3.
Further conversion of the cyclopropanecarboxylic acid (1R,2S)-4
into the aminophosphonic acid (1R,2S)-10 could not be realized by
classical Curtius or Hoffmann rearrangement. All attempts to pre-
pare isocyanate (1R,2S)-7 starting from acyl chloride (1R,2S)-5 ap-
peared unsuccessful. Thus, treatment of the acid (1R,2S)-4 with
2 equiv of oxalic chloride in dichloromethane at reflux led to the
(-)-(1R,2S,1'R)-13
(+)-(1S,2R,1'R)-13
d
d
O
O
P(OEt)2
P(OEt)2
O
O
(+)-(1S,5R)-6
O
O
(-)-(1R,5S)-6
formation of bicyclic a-phosphono-c-lactone (1R,5S)-6 as the sole
product (Scheme 1). This result indicated that the initially formed
acyl chloride (1R,2S)-5 underwent spontaneous lactonization
involving successive acylation and debenzylation of the cis-dis-
posed benzyloxymethyl group.
Scheme 3. Reagents and conditions: (a) 11 (1 equiv), NaH (2 equiv), THF, reflux,
5 h, 65%; (b) MeOH, rt, 10 days; (c) column chromatography, 42%; (d) H2SO4 (cat),
THF, rt, 85%.
The diphenylphosphoryl azide DPPA-mediated modified Curtius
rearrangement11 of acid (1R,2S)-4 into the isocyanate (1R,2S)-7
followed by coupling of the latter with ethanol provided the carba-
mate (1R,2S)-8. Hydrogenolysis of the benzyl-protecting group
from cyclopropane (1R,2S)-8 gave an isolable alcohol (1R,2S)-9
which after dealkylation of the diethyl ester combined with
N-deprotection furnished the aminophosphonic acid (1R,2S)-10
(Scheme 2).
tography.12 Further lactonization of the individual amides 13 pro-
ceeded efficiently in boiling THF in the presence of catalytic
sulfuric acid to afford the expected
a-phosphono-c-lactones
(1R,5S)-6 and (1S,5R)-6.
Transformation of lactone (1S,5R)-6 into aminophosphonic acid
(1S,2R)-10 was carried out according to a literature procedure
(Scheme 4).9 Thus, treatment of the
c
-lactone (1S,5R)-6 with satu-
rated methanolic ammonia followed by acylation of the -hydrox-
yamide gave -acyloxyamide 14. The lead tetraacetate-mediated
Proceeding forward with our approach to 1-amino-2-(hydroxy-
methyl)cyclopropanephosphonic acid (1S,2R)-10 we found that
racemic a-phosphono-c-lactone 6 could be prepared economically
c
c
in 65% yield by treating epibromohydrin 11 with ethyl diet-
oxidative Hoffmann rearrangement of the amide 14 carried out
hoxyphosphorylacetate 2 in the presence of 2 equiv of NaH
in boiling t-butyl alcohol led to carbamate 15.
(Scheme 3). The reaction of
amine 12 gave diastereoisomeric
and (1R,2S,10R)-13 which could be separated by column chroma-
c
-lactone 6 with (R)-
a-phenylethyl-
Routine hydrolysis of the acetyl group allowed us to convert the
carbamate (ꢀ)-(1S,2R)-15 into diethyl N-Boc aminocyclopropane-
phosphonate (ꢀ)-(1S,2R)-16. Finally, sequential treatment of
c
-hydroxyamides (1S,2R,10R)-13

K. Wa˛sek et al. / Tetrahedron: Asymmetry 21 (2010) 2081–2086
2083
O
crude product 3, which was purified by column chromatography
AcO
CONH2
(chloroform/acetone 80:20). Yield = 2.30 g, (62%); colourless oil;
P(OEt)2
a, b
Rf = 0.38. ½a 2D0
¼ þ6:4 (c 1.40, CHCl3). IR (film) m(C@O) 1724, m(P@O)
ꢂ
P(OEt)2
O
1270, m(P–O) 1028. 31P NMR (C6D6): d = 23.14. 1H NMR (C6D6):
O
3
3
O
d = 1.23 (t, JHH = 7.2 Hz, 3H, CH3CH2O); 1.31 (t, JHH = 7.0 Hz, 6H,
(+)-(1S,5R)-6
(+)-(1S,2R)-14
CH3CH2OP); 1.54–1.68 (m, 2H, PCCH2); 2.12–2.27 (m, 1H, PCCH);
2
3
AcO
NHBoc
3.48 (dd, JHH = 10.5 Hz, JHH = 8.7 Hz, 1H, CHHOCH2Ph); 3.78 (dd,
c
2JHH = 10.5 Hz, JHH = 5.5 Hz, 1H, CHHOCH2Ph); 4.11–4.23 (m, 6H,
3
d
P(OEt)2
O
2
CH2OP, CH2O); 4.40 (s, JHH = 5.5 Hz, 2H, OCH2Ph); 7.27–7.35 (m,
5H, CHAr). 13C NMR (CDCl3): d = 13.87 (s, CH3CH2O); 16.10 (d,
3JPC = 6.7 Hz, CH3CH2OP); 16.20 (d, JPC = 6.1 Hz, CH3CH2OP); 16.58
3
(-)-(1S,2R)-15
NHBoc
1
2
(s, PCCH2); 23.77 (d, JPC = 188.5 Hz, PC); 26.31 (d, JPC = 2.8 Hz,
HO
HO
NH2
2
e, f, g
PCCH); 61.43 (s, CH2O); 62.47 (d, JPC = 6.2 Hz, CH2OP); 62.57 (d,
2JPC = 6.5 Hz, CH2OP); 67.40 (s, CH2OCH2Ph); 72.42 (s, OCH2Ph);
127.20 (s, 2 ꢁ CHAr); 127.37 (s, CHAr); 128.10 (s, 2 ꢁ CHAr); 136.40
(s, C1Ar); 166.27 (s, C@O). Anal. Calcd for C18H27O6P: C, 58.37; H,
7.35. Found: C, 58.49; H, 7.31.
P(OEt)2
O
P(OH)2
O
(-)-(1S,2R)-16
(-)-(1S,2R)-10
Scheme 4. Reagents and conditions: (a) satd NH3, MeOH, reflux, 20 h; (b) Et3N
(1.2 equiv), DMAP (cat), Ac2O (1.2 equiv), rt, 15 h, 90%; (c) Pb(OAc)4 (4 equiv), t-
BuOH, reflux, 5 h, 98%; (d) K2CO3 (2 equiv), MeOH, reflux, 17 h, 95%; (e) TFA
(2 equiv), DCM, rt, 3 h; (f) Me3SiBr (4 equiv), DCM, rt, 72 h; (g) propylene oxide
(17 equiv), EtOH, rt, 2 h, 90%.
4.3. (+)-(1R,2S)-2-(Benzyloxymethyl)-1-(diethoxyphosphoryl)
cyclopropanecarboxylic acid 4
To a solution of cyclopropanecarboxylate 3 (2.22 g, 6.00 mmol)
in ethyl alcohol (20 mL), a solution of NaOH (0.36 g, 9.00 mmol) in
water (1.5 mL) was added and the reaction mixture was stirred at
room temperature for 2 days. Then the solvent was evaporated
and the residue was dissolved in water (20 mL) and extracted with
diethyl ether (3 ꢁ 25 mL). Then the water layer was acidified to pH
1 with 3 N HCl and extracted with dichloromethane (3 ꢁ 25 mL).
The combined organic layers were dried (MgSO4) and evaporated
under reduced pressure. The residue crystallized on standby to give
acid 4 as white solid, which was collected by filtration from diethyl
ether. Yield = 2.00 g, (97%); white crystal, mp = 102–104 °C.
phosphonate 16 with trifluoroacetic acid followed by bromotri-
methylsilane and ethanol gave aminophosphonic acid (1S,2R)-10.
3. Conclusions
In conclusion, we have developed a concise and efficient syn-
thesis of (1R,2S)-trans-1-amino-2-(hydroxymethyl)cyclopropane-
phosphonic acid starting from (S)-3-benzyloxy-1,2-propandiol.
Furthermore, (1S,5R)-3-oxabicyclo[3.1.0]hexan-2-on-1-phospho-
nate has been shown to be a practical precursor of (1S,2R)-trans-
1-amino-2-(hydroxymethyl)cyclopropanephosphonic acid.
½
a 2D0
ꢂ
¼ þ6:95 (c 1.50, CHCl3). IR (film) m(C@O) 1764, m(P@O) 1264,
m(P–O) 1020. 31P NMR (CDCl3): d = 27.42. 1H NMR (CDCl3): d = 1.30
(td, JHH = 7.0 Hz, 4JPH = 0.7 Hz, 6H, CH3CH2OP); 1.61 (dd,
3
3JPH = 12.2 Hz, 3JHH = 8.5 Hz, 2H, PCCH2); 2.23 (ddddd, 3JPH = 16.5 Hz,
3JHH = 10.0 Hz, 3JHH = 8.5 Hz, 3JHH = 8.5 Hz, 3JHH = 5.7 Hz, 1H, PCCH);
4. Experimental
4.1. General
2
3
3.55 (dd, JHH = 10.7 Hz, JHH = 8.5 Hz, 1H, CHHOCH2Ph); 3.78 (dd,
2JHH = 10.7 Hz, 3JHH = 5.7 Hz, 1H, CHHOCH2Ph); 4.16 (dq,
3JPH = 3JHH = 7.0 Hz, 1H, CHHOP); 4.17 (dq, JPH = 3JHH = 7.0 Hz, 1H,
3
NMR spectra were recorded on a Bruker DPX 250 instrument at
250.13 MHz for 1H and 62.9 MHz for 13C and 101.3 MHz for 31P
NMR, respectively, using tetramethylsilane as the internal and
85% H3PO4 as the external standard. The multiplicities of carbons
were determined by DEPT experiments. IR spectra were measured
on Specord M80 (Zeiss) instrument. Elemental analyses were per-
formed on Perkin-Elmer PE 2400 analyzer. Melting points were
determined in open capillaries and were uncorrected. Flash chro-
matography are carried out using Fluka silica gel 60 (230–400
mesh). Thin layer chromatography was carried out on commer-
cially available pre-coated plates (Fluka Silica gel on TLC plates).
(S)-(ꢀ)-4-Benzyloxymethyl-2,2-dioxo-1,3,2-dioxolane 1 was pre-
pared according to a literature procedure.8
CHHOP); 4.18 (dq, JPH = 3JHH = 7.0 Hz, 2H, CH2OP); 4.47 (s, 2H,
3
OCH2Ph); 7.25–7.32 (m, 5H, CHAr). 13C NMR (CDCl3): d = 16.04 (d,
3JPC = 6.1 Hz, CH3CH2OP); 16.13 (d, JPC = 5.0 Hz, CH3CH2OP); 17.24
3
(s, PCCH2); 23.38 (d, 1JPC = 190.9 Hz, PC); 26.95 (s, PCCH); 63.01 (d,
2JPC = 6.5 Hz, CH2OP); 63.11 (d, JPC = 6.4 Hz, CH2O)P); 67.22 (s,
2
CH2OCH2Ph); 72.43 (s, OCH2Ph); 127.36 (s, 2 ꢁ CHAr); 128.13 (s,
CHAr); 128.14 (s, 2 ꢁ CHAr); 137.94 (s, C1Ar); 170.34 (d, 2JPC = 8.5 Hz,
C@O). Calcd for C16H23O6P: C, 56.14; H, 6.77. Found: C, 56.23; H, 6.80.
4.4. Diethyl (ꢀ)-(1R,5S)-2-oxo-3-oxabicyclo[3.1.0]hexan-1-
ylphosphonate 69
To a solution of acid 4 (1.71 g, 0.50 mmol) in dichloromethane
(4 mL), oxalyl chloride (0.087 mL, 1.0 mmol) was added and the
reaction mixture was heated at reflux for 4 h. The solvent was
evaporated and the residue was purified by column chromatogra-
phy to give 6 as a colourless oil. Yield = 1.05 g, (90%); colourless
4.2. Ethyl (+)-(1R,2S)-2-(benzyloxymethyl)-1-(diethoxyphospho-
ryl)cyclopropanecarboxylate 3
To a stirred suspension of sodium hydride (0.48 g, 0.02 mol) in
tetrahydrofuran (75 mL) phosphonate 2 (2.0 mL, 0.01 mol) was
added at room temperature. After stirring for 0.5 h, a solution of
oil; ½a 2D0
ꢂ
¼ ꢀ49:7 (c 1.35, CHCl3). 31P NMR (CDCl3): d = 17.50. 1H
NMR (CDCl3): d = 1.30 (ddd, 3JHH = 10.5 Hz, 2JHH = 5.0 Hz,
3
4
3JPH = 5.0 Hz, 1H, PCHH); 1.36 (td, JHH = 7.0 Hz, JPH = 0.5 Hz, 3H,
(S)-(ꢀ)-4-benzyloxymethyl-2,2-dioxo-1,3,2-dioxolane
1 (2.44 g,
3
4
0.01 mol) in tetrahydrofuran (25 mL) was added and the resulting
mixture was stirred at room temperature for 0.5 h and then at re-
flux for 8 h. Next, the reaction mixture was poured into water
(25 mL), extracted with dichloromethane (3 ꢁ 25 mL) and the or-
ganic layer was dried (MgSO4). Removal of the solvent gave the
CH3CH2OP); 1.39 (td, JHH = 7.0 Hz, JPH = 0.5 Hz, 3H, CH3CH2OP);
3
3
2
1.86 (ddd, JPH = 15.2 Hz, JHH = 7.7 Hz, JHH = 5.0 Hz, 1H, PCHH);
2.71 (ddddd, JPH = 15.0 Hz, JHH = 10.5 Hz, JHH = 7.7 Hz, JHH
3
3
3
3
=
3
5.0 Hz, JHH = 4.7 Hz, 1H, PCCH); 4.19–4.29 (m, 5H, CH2OP,
PCCHCHH); 4.36 (dd, 2JHH = 9.5 Hz, 3JHH = 4.7 Hz, 1H, PCCHCHH).

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K. Wa˛sek et al. / Tetrahedron: Asymmetry 21 (2010) 2081–2086
4.5. Ethyl (+)-(1R,2S)-2-(benzyloxymethyl)-1-(diethoxyphospho-
ryl)cyclopropylcarbamate 8
der reduced pressure and the residue was dissolved in ethanol
(5 mL) and stirred for 15 min. Evaporation of the solvent afforded
an oily residue which was treated with an excess of propylene oxide
(1 mL) to give (1R,2S)-10 as a white solid. Yield = 0.13 g, (95%); white
To a solution of acid (1R,2S)-4 (1.02 g, 3.00 mmol)in toluene
(5 mL) were added triethylamine (0.50 mL), 3.60 mmol) and
diphenylphosphoryl azide (0.71 mL, 3.30 mmol). The resulting
mixture was heated at 110 °C for 1 h. The mixture was then cooled
to room temperature, diluted with diethyl ether (10 mL) and
quenched with saturated aq NH4Cl (10 mL). The organic layer
was separated and water layer was extracted with diethyl ether
(3 ꢁ 20 mL). The combined organic layers were washed with brine
(5 mL), dried (MgSO4), filtered and concentrated under reduced
pressure. The residue was dissolved in toluene (10 mL) and ethyl
alcohol (0.27 mL), 4.50 mmol) was added. The resulting mixture
was heated at reflux for 5 h. Evaporation of the solvent afforded
crude 8, which was purified by column chromatography.
crystals, mp = 70–72 °C (lit.6 mp = 71–73 °C); ½a 2D0
¼ þ41:0 (c 1.00,
ꢂ
H2O). 31P NMR (D2O): d = 12.19. 1H NMR (D2O): d = 0.98 (ddd,
3
2
3JPH = 12.2 Hz, JHH = 6.7 Hz, JHH = 5.0 Hz, 1H, PCCHH); 1.20 (ddd,
3JPH = 15.2 Hz, 3JHH = 8.7 Hz, 2JHH = 5.0 Hz, 1H, PCCHH); 1.54 (ddddd,
3JPH = 15.7 Hz, 3JHH = 8.7 Hz, 3JHH = 6.7 Hz, 3JHH = 6.5 Hz, 3JHH = 5.0 Hz
1H, PCCH); 1.87 (br s, 1H, OH); 3.65 (dd, 2JHH = 12.0 Hz, 3JHH = 6.5 Hz,
2
3
1H, CHHOH); 3.85 (dd, JHH = 12.0 Hz, JHH = 5.0 Hz, 1H, CHHOCH);
4.00 (br s, 4H, HOP, NH2).
4.8. Diethyl 2-oxo-3-oxabicyclo[3.1.0]hexan-1-ylphosphonate 6
To a stirred suspension of sodium hydride (1.2 g, 0.05 mol) in
tetrahydrofuran, phosphonate 2 (10 mL, 0.05 mol) was added
dropwise at room temperature and stirring was continued for
0.5 h. A solution of epibromohydrine 11 (4.3 mL, 0.05 mol) in tetra-
hydrofuran (20 mL) was added and the resulting mixture was
heated at reflux for 5 h. The mixture was then quenched with
water (20 mL) and evaporated under reduced pressure. The residue
was dissolved in dichloromethane (50 mL), the organic layer was
separated and the water layer was extracted with dichloromethane
(2 ꢁ 25 mL). The combined organic layers were dried (MgSO4), fil-
tered and evaporated to give crude 6, which was purified by col-
umn chromatography (CHCl3/acetone 90:10). Yield = 7.6 g, (65%);
colourless oil; Rf = 0.30.
Yield = 0.87 g, (75%); yellowness oil. ½a D20
¼ þ54:0 (c 1.35, CHCl3).
ꢂ
IR (film) m(C@O) 1764, m(P@O) 1264, m(P–O) 1020. 31P NMR (CDCl3):
d = 24.64 1H NMR (CDCl3): d = 1.16–1.24 (m, 1H, PCCHH); 1.26 (t,
3
3JHH = 7.0 Hz, 3H, CH3CH2O); 1.30 (t, JHH = 7.0 Hz, 3H, CH3CH2OP);
3
4
1.31 (td, JHH = 7.0 Hz, JPH = 0.5 Hz, 3H, CH3CH2OP); 1.68 (ddd,
3JPH = 13.5 Hz, JHH = 9.0 Hz, JHH = 5.5 Hz, 1H, PCCHH); 1.95
3
2
3
3
3
3
(ddddd, JPH = 16.7 Hz, JHH = 10.2 Hz, JHH = 9.0 Hz, JHH = 6.7 Hz,
3JHH = 5.25 Hz 1H, PCCH); 3.25 (dd, JHH = 10.2 Hz, JHH = 10.2 Hz,
2
3
2
3
1H, CHHOCH2Ph); 3.85 (dd, JHH = 10.2 Hz, JHH = 5.2 Hz, 1H,
CHHOCH2Ph); 4.08–4.25 (m, 6H, CH2O, CH2OP); 4.46 (d,
2JHH = 12.0 Hz, 1H, CHHPh); 4.61 (d, JHH = 12.0 Hz, 1H, CHHPh);
2
5.19 (br s, 1H, NH); 7.25–7.32 (m, 5H, CHAr). 13C NMR (CDCl3):
d = 14.48 (s, CH3CH2O); 16.26 (s, CH3CH2OP); 16.36 (s, CH3CH2OP);
1
17.35 (s, PCCH2); 22.13 (s, PCCH); 30.05 (d, JPC = 220.2 Hz, PC);
4.9. Diethyl (+)-(1S,2R)-2-(hydroxymethyl)-1-((R)-1-phenylethyl-
carbamoyl)cyclopropylphosphonate 13
2
60.96 (s, CH2O); 62.48 (d, JPC = 5.8 Hz, CH2OP); 63.92 (d,
2JPC = 5.4 Hz, CH2OP); 68.81 (s, CH2OCH2Ph); 72.61 (s, CH2Ph);
127.57 (s, 2 ꢁ CHAr); 127.75 (s, CHAr); 128.86 (s, 2 ꢁ CHAr);
137.95 (s, C1Ar); 156.27 (s, C@O). Calcd for C18H28NO6P: C, 56.10;
H, 7.32; N, 3.63. Found: C, 56.00; H, 7.28; N, 3.61.
To a solution of racemic lactone 6 (2.50 g, 0.01 mol) in methanol
(20 mL), (R)-a-phenylethylamine (2.55 mL, 0.02 mol) was added
and the resulting solution was stirred at room temperature for
10 days. The solvent was evaporated and the oily residue was dis-
solved in dichloromethane (10 mL), washed with 1 M HCl (20 mL),
water (20 mL), dried (MgSO4) and evaporated. The residue was sub-
jected to column chromatography yielding, in order of elution,
amides (1S,2R,10R)-13 and (1R,2S,10R)-13. Yield = 1.50 g (42%); col-
4.6. Ethyl (+)-(1R,2S)-1-(diethoxyphosphoryl)-2-(hydroxyl
methyl)cyclopropylcarbamate 9
Phosphonate (1R,2S)-8 (0.77 g, 2.0 mmol) was added to a stirred
suspension of 10% Pd/C (5 mg) in ethanol (5 mL). The stirring was
continued under an H2 atmosphere for 3 h. Then, the catalyst was fil-
tered off and the filtrate was concentrated under vacuum to give
crude product 9, which was used in the next step without purifica-
ourless oil; Rf = 0.12. ½a D20
¼ þ68:8 (c 1.39, CHCl3). IR (film) m(O–H)
ꢂ
3048, m(C@O) 1664, m(P@O) 1232, m(P–O) 1024. 31P NMR (CDCl3):
d = 25.15. 1H NMR (CDCl3): d = 1.27 (t, 3JHH = 7.0 Hz, 3H, CH3CH2OP);
3
4
1.33 (td, JHH = 7.0 Hz, JPH = 0.5 Hz, 3H, CH3CH2OP); 1.36–1.49 (m,
tion. Yield = 0.56 g, (95%); yellowness oil. ½a D20
ꢂ
¼ þ49:8 (c 1.25,
1H, PCCHH); 1.51 (d, JHH = 7.0 Hz, 3H, PhCHCH3); 2.00 (ddddd,
3
CHCl3). 31P NMR (CDCl3): d = 24.02. 1H NMR (CDCl3): d = 0.70 (ddd,
3JPH = 22.7 Hz, JHH = 11.0 Hz, JHH = 9.2 Hz, JHH = 7.0 Hz, JHH
=
3
3
3
3
2
3
3JPH = 12.0 Hz, JHH = 6.7 Hz, JHH = 6.0 Hz, 1H, PCCHH); 1.31 (t,
4.7 Hz, 1H, PCCH); 2.77 (ddd, 3JPH = 8.5 Hz, 3JHH = 7.0 Hz,
3JHH = 7.0 Hz, 3H, CH3CH2O); 1.33 (t, JHH = 7.0 Hz, 3H, CH3CH2OP);
2JHH = 5.7 Hz, 1H, PCCHH); 3.34 (dd, JHH = 12.2 Hz, JHH = 9.0 Hz,
3
2
3
1.35 (td, 3JHH = 7.0 Hz, 4JPH = 0.7 Hz, 3H, CH3CH2OP); 1.41 (br s, 1H,
1H, CHHOH); 3.85 (ddd, 2JHH = 12.25 Hz, 3JHH = 11.0 Hz, 4JPH = 1.5 Hz,
3
3
2
3
OH); 1.48 (ddd, JPH = 13.2 Hz, JHH = 8.7 Hz, JHH = 5.0 Hz, 1H,
PCCHH); 1.97 (ddddd, JPH = 16.5 Hz, JHH = 10.0 Hz, JHH = 8.7 Hz,
1H, CHHOH); 4.09 (dq, JPH = 3JHH = 7.0 Hz, 2H, CH2OP); 4.17 (dq,
3
3
3
3
3JPH = 3JHH = 7.0 Hz, 2H, CH2OP); 5.10 (dq, JHH = 3JHH = 7.0 Hz, 1H,
3
2
3
3JHH = 6.0 Hz, JHH = 5.0 Hz, 1H, PCCH); 3.10 (dd, JHH = 11.2 Hz,
3JHH = 10.0 Hz, 1H, CHHOH); 3.85 (dd, 2JHH = 11.25 Hz, 3JHH = 5.0 Hz,
1H, CHHOH); 4.05–4.28 (m, 6H, CH2O, CH2OP); 5.07 (br s, 1H, NH).
13C NMR (CDCl3): d = 14.34 (s, CH3CH2O); 16.20 (s, CH3CH2OP);
16.27 (s, CH3CH2OP); 17.18 (s, PCCH2); 21.87 (s, PCCH); 31.05 (d,
1JPC = 215.3 Hz, PC); 60.24 (s, CH2O); 61.96 (d, 2JPC = 5.8 Hz, CH2OP);
62.12 (d, 2JPC = 5.4 Hz, CH2OP); 74.81 (s, CH2OH); 155.74 (s, C@O). IR
PhCHCH3); 7.25–7.35 (m, 5H, CHAr); 7.51 (bd, JHH = 7.0 Hz, 1H,
NH). 13C NMR (CDCl3): d = 14.19 (d, JPC = 3.7 Hz, PCCH2); 16.19 (d,
2
3JPC = 6.1 Hz, CH3CH2OP); 16.25 (d, 3JPC = 6.1 Hz, CH3CH2OP); 21.84
1
2
(s, PhCHCH3); 25.78 (d, JPC = 178.9 Hz, PC); 26.83 (d, JPC = 3.1 Hz,
PCCH); 49.63 (s, PhCHCH3); 61.15 (d, JPC = 1.7 Hz, CH2OH); 62.88
3
2
2
(d, JPC = 6.4 Hz, CH2OP); 63.10 (d, JPC = 6.3 Hz, CH2OP); 125.87 (s,
2 ꢁ CHAr); 127.29 (s, CHAr); 128.56 (s, 2 ꢁ CHAr); 142.95 (s, C1Ar);
2
(film)
m
(C@O) 1764,
m(P@O) 1264,
m(P–O) 1020.
165.62 (d, JPC = 8.7 Hz, C@O). Calcd for C17H26NO5P: C, 57.46; H,
7.37. Found: C, 57.31; H, 7.34.
4.7. (+)-(1R,2S)-1-Amino-2-(hydroxymethyl)cyclopropylphos-
phonic acid 10
4.10. Diethyl (ꢀ)-(1R,2S)-2-(hydroxymethyl)-1-((R)-1-phenyleth-
ylcarbamoyl)cyclopropylphosphonate 13
A mixture of phosphonate (1R,2S)-9 (0.25 g, 0.85 mmol) and
bromotrimethylsilane (0.45 mL, 4.25 mmol) in dichloromethane
(5 mL) was heated at reflux for 3 h. The solvent was evaporated un-
Yield = 1.50 g (42%); colourless oil; Rf = 0.10. ½a D20
¼ þ38:95 (c
ꢂ
1.39, CHCl3). 31P NMR (CDCl3): d = 25.17. 1H NMR (CDCl3): d = 1.27

K. Wa˛sek et al. / Tetrahedron: Asymmetry 21 (2010) 2081–2086
2085
3
4
3
(td, JHH = 7.0 Hz, JPH = 0.5 Hz 3H, CH3CH2OP); 1.31 (td, JHH
=
ature, diethyl ether (2.5 mL) followed by NaHCO3 (0.134 g,
1.60 mmol) were added, and the mixture was stirred for 10 min
at room temperature. The mixture was filtered through a short plug
of silica gel and the filtrate evaporated. The residue was purified by
column chromatography to give 15. Yield = 0.56 g (98%); colourless
4
7.0 Hz, JPH = 0.5 Hz, 3H, CH3CH2OP); 1.37–1.47 (m, 1H, PCCHH-
C3); 1.50 (d, 3JHH = 7.0 Hz, 3H, PhCHCH3); 2.00 (ddddd,
3JPH = 22.5 Hz, JHH = 11.5 Hz, JHH = 8.7 Hz, JHH = 6.7 Hz, JHH
=
=
3
3
3
3
3
3
2
5.0 Hz, 1H, PCCH); 2.97 (ddd, JPH = 7.0 Hz, JHH = 6.7 Hz, JHH
6.2 Hz, 1H, PCCHH); 3.45 (ddd, JHH = 13.0 Hz, JHH = 8.7 Hz,
3JPH = 5.0 Hz, 1H, CHHOH); 3.92 (ddd, 2JHH = 13.0 Hz, 3JHH = 11.5 Hz,
4JPH = 1.5 Hz, 1H, CHHOH); 4.09 (dq, 3JPH = 3JHH = 7.0 Hz, 2H, CH2OP);
oil; Rf = 0.16 (chloroform/acetone 90:10). ½a D20
¼ ꢀ6:0 (c 1.20,
ꢂ
2
3
CHCl3). 31P NMR (CDCl3): d = 24.16. 1H NMR (CDCl3): d = 1.18 (ddd,
3
2
3JPH = 6.2 Hz, JHH = 6.0 Hz, JHH = 4.7 Hz, 1H, PCCHH); 1.31 (td,
4.13 (dq, JPH = 3JHH = 7.0 Hz, 2H, CH2OP); 5.11 (dq, JHH
=
3JHH = 7.0 Hz, JPH = 0.5 Hz, 3H, CH3CH2OP); 1.33 (td, JHH = 7.0 Hz,
4JPH = 0.5 Hz, 3H, CH3CH2OP); 1.43 (s, 9H, (CH3)3C); 1.72 (ddd,
3JPH = 12.5 Hz, 3JHH = 9.5 Hz, 2JHH = 4.7 Hz, 1H, PCCHH); 1.83 (ddddd,
3
3
4
3
3JHH = 7.0 Hz, 1H, PhCHCH3); 7.25–7.34 (m, 5H, CHAr); 7.51 (bd,
3JHH = 7.0 Hz, 1H, NH). 13C NMR (CDCl3): d = 14.04 (d, JPC = 3.7 Hz,
2
3
3
3
3
3
3
PCCH2); 16.15 (d, JPC = 6.1 Hz, CH3CH2OP); 16.25 (d, JPC = 6.0 Hz,
CH3CH2OP); 21.89 (s, PhCHCH3); 25.83 (d, JPC = 179.2 Hz, PC);
3JPH = 15.5 Hz, JHH = 10.7 Hz, JHH = 9.5 Hz, JHH = 9.2 Hz, JHH
=
1
2
3.2 Hz, 1H, PCCH); 2.08 (s, 3H, CH3CO); 3.98 (dd, JHH = 12.0 Hz,
3JHH = 9.2 Hz, 1H, CHHO); 4.13 (dq, 3JPH = 3JHH = 7.0 Hz, 4H, CH2OP);
4.35 (ddd, 2JHH = 12.0 Hz, 3JHH = 3.2 Hz, 1H, CHHO); 5.48 (br s, 1H, NH).
2
26.79 (d, JPC = 3.2 Hz, PCCH); 49.65 (s, PhCHCH3); 61.16 (d,
3JPC = 2.0 Hz, CH2OH); 62.91 (d, JPC = 6.5 Hz, CH2OP); 63.05 (d,
2
2JPC = 6.3 Hz, CH2OP); 125.88 (s, 2 ꢁ CHAr); 127.25 (s, CHAr); 128.55
(s, 2 ꢁ CHAr); 142.92 (s, C1Ar); 165.65 (d, 2JPC = 8.7 Hz, C@O).
4.15. tert-Butyl (ꢀ)-(1S,2R)-1-(diethoxyphosphoryl)-2-(hydroxyl
methyl)cyclopropylcarbamate16
4.11. Diethyl (+)-(1S,5R)–2-oxo-3-oxabicyclo[3.1.0]hexan-1-
ylphosphonate 6
Potassium carbonate (0.18 g, 1.30 mmol) was added to a stirred
solution of 15 (0.25 g, 0.65 mmol) in MeOH (5 mL) and the reaction
mixture was heated at reflux for 17 h. The solvent was evaporated,
after which water (5 mL) was added to the residue, and the result-
ing solution was extracted with ether (3 ꢁ 10 mL). The organic
layer was dried (MgSO4), and the solvent was evaporated to give
crude product, which was purified by column chromatography.
Yield = 0.20 g (95%); colourless oil; Rf = 0.09 (chloroform/acetone
Individual amides (1S,2R,10R)-13 and (1R,2S,10R)-13 were stirred
for 3 h with 5 mL of 2:1 (H2SO4/H2O). Extractive work-up and chro-
matography as in the preparation of racemic 6 gave (1R,5S)-6 and
(1S,5R)-6 lactones. Yield = 1.00 g (85%); colourless oil;
þ49:5 (c 1.35, CHCl3).
½
a 2D0
ꢂ
¼
4.12. Diethyl (ꢀ)-(1R,5S)-2-oxo-3-oxabicyclo[3.1.0]hexan-1-
90:10). ½a 2D0
ꢂ
¼ ꢀ49:5 (c 1.20, CHCl3). 31P NMR (CDCl3): d = 24.22.
3
3
ylphosphonate 6
1H NMR (CDCl3): d = 0.62 (ddd, JPH = 12.5 Hz, JHH = 6.7 Hz,
2JHH = 6.7 Hz,1H, PCCHH); 1.31 (t, JHH = 7.0 Hz, 3H, CH3CH2OP);
3
Yield = 1.00 g (85%); colourless oil; ½a D20
ꢂ
¼ ꢀ49:7 (c 1.35, CHCl3).
1.34 (td, JHH = 7.0 Hz, JPH = 0.5 Hz, 3H, CH3CH2OP); 1.43 (br s,
3
4
3
1H, CH2OH); 1.46 (s, 9H, (CH3)3C); 1.48 (ddd, JPH = 13.0 Hz,
3
3
4.13. (+)-(1S,2R)-2-carbamoyl-2-(diethoxyphosphoryl)cyclopro-
2JHH = 6.7 Hz, JHH = 5.5 Hz, 1H, PCCHH); 2.02 (ddtd, JPH = 15.7 Hz,
pylmethyl acetate 149
3JHH = 12.0 Hz, JHH = 6.7 Hz, JHH = 5.5 Hz, 1H, PCCH); 3.17 (dd,
3
3
2JHH = 12.2 Hz, 3JHH = 12.0 Hz, 1H, CHHOH); 4.00 (bd, 2JHH = 12.2 Hz,
3
Lactone 9 (0.94 g, 4.00 mmol) was dissolved in methanol
(10 mL), after which methanol saturated with ammonia (5.0 M,
8.0 mL, 40 mmol) was added and the solution stirred for 20 h at
room temperature. The solvent was then evaporated in vacuo and
the residue dissolved in dichloromethane (15 mL) and cooled to
0 °C. Triethylamine (0.67 ml, 4.80 mmol) and DMAP (30 mg) were
then added to the solution, followed by the dropwise addition of
acetic anhydride (0.45 ml, 4.80 mol). After stirring for 15 h at room
temperature, water was added and the solution was extracted with
dichloromethane (3 ꢁ 20 mL). The organic layers were dried
(MgSO4) and evaporated. The residue was purified by column chro-
matography to give 14. Yield = 1.05 g (90%); colourless oil; Rf = 0.05
1H, CHHOH); 4.21 (dq, JPH = 3JHH = 7.0 Hz, 2H, CH2OP); 4.22 (dq,
3JPH = 3JHH = 7.0 Hz, 2H, CH2OP); 5.11 (br s, 1H, NH.
4.16. (ꢀ)-(1S,2R)-1-Amino-2-(hydroxymethyl)cyclopropylphos-
phonic acid 10
To a solution of phosphonate 16 (0.20 g, 0.62 mmol) in dichloro-
methane (10 mL), trifluoroacetic acid (0.20 mL, 2.50 mmol) was
added. The reaction mixture was stirred at room temperature for
3 h. The solvent was evaporated, after which the residue was dis-
solved in dichloromethane (10 mL), washed with saturated NaH-
CO3 (5 mL), water (5 mL) and dried (MgSO4). After evaporation of
the solvent, the residue was dissolved in dichloromethane
(10 mL) after which bromotrimethylsilane (0.34 mL, 3.10 mmol)
was added. The resulting mixture was stirred at room temperature
for 72 h. The solvent was evaporated under reduced pressure and
the residue was dissolved in ethanol (10 mL) and stirred for
15 min. Evaporation of the solvent afforded an oily residue, which
was treated with an excess of propylene oxide (1 mL) to give 10 as
a white solid. Yield = 0.11 g, (90%); white crystals, mp = 70–72 °C
(chloroform/acetone 90:10). ½a D20
ꢂ
¼ þ18:0 (c 1.35, CHCl3). 31P NMR
(CDCl3): d = 25.13. 1H NMR (CDCl3): d = 1.34 (td, JHH = 7.0 Hz,
3
4JPH = 0.5 Hz, 3H, CH3CH2OP); 1.37 (td, JHH = 7.0 Hz, JPH = 0.5 Hz,
3
4
3
3
2
3H, CH3CH2OP); 1.44 (ddd, JPH = 10.2 Hz, JHH = 7.0 Hz, JHH
=
=
3
3
2
4.5 Hz, 1H, PCCHH); 1.73 (ddd, JPH = 14.5 Hz, JHH = 9.0 Hz, JHH
4.5 Hz, 1H, PCCHH); 2.05 (s, 3H, CH3CO); 2.10 (ddddd, 3JPH = 15.5 Hz,
3
3
3
3JHH = 9.0 Hz, JHH = 8.7 Hz, JHH = 7.0 Hz, JHH = 6.0 Hz, 1H, PCCH);
2
3
3.96 (dd, JHH = 11.7 Hz, JHH = 8.7 Hz, 1H, CHHO); 4.19 (dq,
3JPH = 3JHH = 7.0 Hz, 2H, CH2OP); 4.19 (dq, JPH = 3JHH = 7.0 Hz, 1H,
(lit.9 mp = 71–73 °C). ½a 2D0
¼ ꢀ40:95 (c 1.00, H2O).
ꢂ
3
CHHOP); 4.20 (dq, JPH = 3JHH = 7.0 Hz, 1H, CHHOP); 4.35 (ddd,
3
3
4
2JHH = 11.7 Hz, JHH = 6.00 Hz, JPH = 0.7 Hz, 1H, CHHO); 5.69 (br s,
Acknowledgement
1H, CONHH); 7.35 (br s, 1H, CONHH).
The authors thank Professor Ryszard Bodalski (Technical Uni-
versity of Lodz) for stimulating discussions.
4.14. (ꢀ)-(1S,2R)-2-(tert-Butoxycarbonylamino)-2-(diethoxy
phosphoryl)cyclopropylmethyl acetate 159
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