Formal synthesis of Thienamycin

Article abstract of DOI:10.1038/ja.2017.44

A formal synthesis of Thienamycin from ethyl (E)-crotonate and a cyclic five-membered nitrone derived from 2-deoxy-d-ribose is described. The synthesis involves 1,3-dipolar cycloaddition, cleavage of the N-O bond in the adduct, and intramolecular N-acylation to afford a bicyclic carbapenam skeleton. Subsequent transformations of the five-membered ring substituents provide the title compound.

Full text of DOI:10.1038/ja.2017.44

The Journal of Antibiotics (2017), 1–7
2017 Japan Antibiotics Research Association All rights reserved 0021-8820/17
www.nature.com/ja
&
ORIGINAL ARTICLE
Formal synthesis of Thienamycin
Michał Pieczykolan, Bartłomiej Furman and Marek Chmielewski
A formal synthesis of Thienamycin from ethyl (E)–crotonate and a cyclic five-membered nitrone derived from 2-deoxy-D-ribose is
described. The synthesis involves 1,3-dipolar cycloaddition, cleavage of the N–O bond in the adduct, and intramolecular
N-acylation to afford a bicyclic carbapenam skeleton. Subsequent transformations of the five-membered ring substituents
provide the title compound.
The Journal of Antibiotics advance online publication, 5 April 2017; doi:10.1038/ja.2017.44
INTRODUCTION
RESULTS AND DISCUSSION
In 1979, Tufariello et al.1 reported a simple and effective synthesis of Nitrone 3 seemed to be a very attractive substrate for Tufariello's
synthesis of Thienamycin,1 since it was expected to promote the
the basic skeleton of the racemic carbapenem antibiotic
Thienamycin2–5 which continually attracts the interest of industrial
and academic laboratories owing to its high antibacterial activity and
resistance to β-lactamase enzymes.6–14 Due to the endo approach of
methyl (E)-crotonate to the cyclic five-membered nitrone, the relative
configuration of the three stereogenic centers formed during the
1,3-dipolar cycloaddition step is the same as in protected antibiotic 1
(Scheme 1).1
A few years later we expanded on Tufariello’s idea1 to carry out the
stereocontrolled formation of N,4-diaryl and aryl–alkyl β-lactams from
α,β-unsaturated sugar-derived lactones and corresponding open-chain
nitrones.15 The obtained results have prompted us recently to apply
that strategy for the effective synthesis of Ezetimibe, a potent inhibitor
of cholesterol absorption.16,17
desired absolute configuration of all stereogenic centers in the
1,3-dipolar cycloadduct, the same as in the target antibiotic,
whereas substituents in the pyrrolidine ring should have allowed
straightforward introduction of the carboxylic acid and cysteamine
moieties present in 1.22
1,3-Dipolar cycloaddition of ethyl crotonate and nitrone 3 in
a toluene solution took 24 h at 40 °C, providing adduct 6 as the
only product in 95% yield. The structure and configuration of 6 were
proved by NMR. The N–O bond cleavage in 6 was performed using a
standard procedure with zinc and 10% hydrochloric acid to afford
amino alcohol 7. Subsequently, the hydroxyl group in 7 was silylated
with tert-butyldiphenylsilyl chloride to give product
8 which
was treated with t-butyl magnesium bromide to afford the bicyclic
β-lactam 9 in 90% yield. Since the hydroxyl group liberated during the
reduction of the N–O bond required protection, we could not use the
partially deprotected nitrone 4 for the 1,3-dipolar cycloaddition step
due to the higher reactivity of the primary hydroxyl group.22
Regioselective monodebenzylation of 9 by hydrogenolysis or the
treatment with BCl3/dimethyl sulfide complex failed. Numerous
carefully performed experiments provided a mixture of compound
10 with deprotected primary hydroxyl and fully deprotected
compound 11. The best result of the deprotection of the primary
hydroxyl was achieved with BCl3/dimethyl sulfide at − 20 °C, but the
reaction was capricious, affording 10 in yields varying between 20 and
70%. It should be stressed that the debenzylation of both hydroxyl
groups in 9 with BCl3 yielded 11 in 95% yield.
Very recently, we have reported
a synthesis of protected
Thienamycin (1) using the Kinugasa reaction18,19 involving the
cyclic nitrone 3 derived from 2-deoxy-D-ribose and its partly
deprotected derivative 4 with terminal acetylene 2 derived from
D-lactic acid.20,21 The cis substitution of the four-membered ring,
characteristic of the main product of the Kinugasa reaction, was the
major drawback of this synthetic strategy. This was partly overcome,
however, by the application of tetramethylguanidine as the base
instead of trimethylamine. This change effected the preferential
formation of the trans Kinugasa adduct 5 which, however, required
chromatographic separation from the accompanying cis isomer
(Scheme 2).21
The synthesis of nitrone 3 prompted us to employ it in 1,3-dipolar
cycloaddition reaction with unsaturated sugar-derived γ- and
δ-lactones.22 The obtained results followed our previous observations
made for other five-membered ring nitrones derived from tartaric and
malic acids.23 Owing to the preferential anti-exo cycloaddition, the
final β-lactams exhibited the undesired syn configuration of the four-
membered ring protons.22
Looking for discrimination of the hydroxyl groups in the
five-membered ring of compound 11, we investigated regioselective
oxidation (Scheme 3). Oxidation of 11 with MnO2 in dichloro-
methane gave hydroxy ketone 12 in 54% yield after 24 h, whereas
PCC yielded the same product after 30 min in 60% yield. Swern
oxidation of 11 provided unsaturated aldehyde 13 in 22% yield.
Compound 12 could offer an entry to possible modifications of the
Institute of Organic Chemistry, Polish Academy of Sciences, Warsaw, Poland
Correspondence: Professor M Chmielewski, Institute of Organic Chemistry, Polish Academy of Sciences, Kasprzaka 44/52, Warsaw 01-224, Poland.
E-mail: marek.chmielewski@icho.edu.pl
Received 26 September 2016; revised 23 January 2017; accepted 3 March 2017

Synthesis of Thienamycin
M Pieczykolan et al
2
TBSO
HO
MeO2C
H
H
H
N
H
N
MeO2C
H
H
N
CO2Me
NHAc
S
+
HN
OH
N
O
O
O
O
CO2Me
protected Thienamycin 1
Scheme 1 Tufariello’s synthesis of the basic skeleton of Thienamycin.
TBSO
H
H
N
OTBS
(R)
OBn
OBn
OBn
OH
+
1
OBn
OH
N
N
O
O
O
2
4
3
5
Scheme 2 Synthesis of protected Thienamycin using the Kinugasa reaction.
EtO2C
H
TBDPSO
H
H
H
N
EtO2C
OBn
CO2Et
1. Zn, 10% HCl, 99%
t-BuMgBr, THF
OBn
CH2OBn
+
N
OBn
OBn
HN
OR
90%
N
2. TBDPS-Cl, Et3N,
99%
O
CH2OBn
O
O
CH2OBn
CH2OBn
3
6
9
7: R=H
8: R=TBDPS
TBDPSO
TBDPSO
+
TBDPSO
TBDPSO
i) TEMPO, KBr,
NaHCO3,NaOCl
H
H
N
H
H
N
H
H
N
H
H
1. TrCl, Et3N, 92%
2. MsCl, Et3N, 98%
3. BCl3, 93%
BCl3⋅Me2S
or BCl3
OBn
CH2OH
OH
OR1
N
ii) CH2N2, 92%
O
O
O
O
CH2OH
CH2OR2
CO2CH3
17
10
11
14: R1=H, R2=Tr
15: R1=Ms, R2=Tr
16: R1=Ms, R2=H
Swern Ox.
22%
PCC
60%
TBDPSO
TBDPSO
H
H
N
H
H
N
O
O
O
CH2OH
CHO
13
12
Scheme 3 Synthesis of protected Thienamycin following Tufariello’s strategy.
carbapenem structure. Low yield of aldehyde 13 rendered its oxidation corresponding β-lactams 23 and 24 (Scheme 4). Deprotection of the
to unsaturated carboxylic acid (which had previously been trans- hydroxymethyl group in 23 with CAN effected desilylation in the side
formed into Thienamycin 1) unpractical.24 Methyl ester of acid 17
chain as well, whereas removal of the PMB group with DDQ
could be easily obtained by a standard five-step procedure involving
tritylation of 11, mesylation of the trityl derivative 14, detritylation of
15, oxidation of the hydroxymethyl group in 16 to a carboxylic acid
followed by β-elimination of the mesylate, and final methylation of the
acid with diazomethane to afford 17.
Due to issues with regioselective debenzylation, we synthesized
nitrone 18 with the primary hydroxyl group protected using
a PMB group. The reaction sequence involved the silylation of
the terminal hydroxymethyl in methyl 2-deoxy-D-riboside with
TBDPS–Cl, benzylation of the other hydroxyl,25 desilylation, and
p-methoxybenzylation of the primary hydroxyl group. Subsequent
standard transformations following known procedures provided
nitrone 18 in 47% overall yield (Supplementary Information).
Cycloaddition of nitrone 18 and ethyl crotonate provided adduct 19
which subsequently was subjected to the cleavage of the N–O bond to
afford amino alcohol 20 which was then subjected to the protection of
the hydroxyl group with t-butyldimethylsilyl or t-butyldiphenylsilyl to
proceeded well to provide carbapenams 5 and 10. Hydroxymethyl
groups in compounds 5 and 10 were oxidized with TEMPO and
sodium hypochlorite to afford acids which were treated with
diazomethane without purification to give the corresponding methyl
esters 25 and 26 in 84% overall yield (Scheme 4). Compound 25 had
already been transformed in our laboratory into protected Thienamy-
cin 120 using a protocol described by Hanessian26 and others.11,27,28
CONCLUSION
It was shown that the application of five-membered ring nitrones
derived from 2-deoxy-D-ribose 3 and 18 to Tufariello’s strategy1 offers
a very attractive entry to carbapenem antibiotics, offering high
stereoselectivity and good yields of all steps. This was demonstrated
by the formal synthesis of protected Thienamycin 1.
EXPERIMENTAL PROCEDURE
Melting points were determined using Köfler hot-stage apparatus with
give 21 and 22, respectively, which were transformed into a microscope and were uncorrected. Proton and carbon NMR spectra were
The Journal of Antibiotics

Synthesis of Thienamycin
M Pieczykolan et al
3
EtO2C
RO
H
H
N
H
H
N
EtO2C
1. Zn, 10% HCl,
99%
OBn
CO2Et
t-BuMgBr, THF
OBn
OBn
OBn
+
96%
HN
OR
N
2. TBS-Cl, 98% or
TBDPS-Cl, 99%,
Et3N
O
O
CH2OPMB
O
CH2OPMB
CH2OPMB
CH2OPMB
18
19
20: R=H
23: R=TBS, 78%
21: R=TBS
22: R=TBDPS
24: R=TBDPS, 81%
TBSO
RO
H
RO
H
N
H
H
H
H
i) TEMPO, KBr,
NaHCO3,NaOCl
NHAc
S
DDQ
OBn
OBn
CH2OH
N
ii) CH2N2
N
O
O
O
CO2Me
CO2Me
protected Thienamycin 1
5: R=TBS, 77%
10: R=TBDPS, 75%
25: R=TBS, 84%
26: R=TBDPS, 84%
Scheme 4 Intermediates in the synthesis of protected Thienamycin involving PMB-protected nitrone 18.
recorded on a Varian VNMRS Spectrometer at 600 MHz and 150 MHz, bicarbonate and extracted with AcOEt. The extract was dried (Na2SO4) and
respectively, in CDCl3 or C6D6. Infrared spectra were obtained on an evaporated to afford 7, 42 mg (99%), which was used for the next step without
FT–IR–1600 Perkin–Elmer spectrophotometer. Optical rotations were mea- chromatographic purification.
sured with a JASCO J–2000 digital polarimeter. High resolution mass spectra
were recorded on an ESI–TOF Mariner spectrometer (Perspective Biosystem).
Thin layer chromatography (TLC) was performed on aluminum silica gel 60
F254 sheets from Merck. Column chromatography (CC) was carried out using
Merck silica gel (230–400 mesh). The TLC spots were visualized by UV
(254 nm) and by treatment with an alcoholic solution of ninhydrine, aqueous
solution of KMnO4 or with ceric sulfate/phosphomolybdic acid solution. All
solvents were dried and purified applying standard techniques.
Colorless syrup; [α]D +27.6 (c 2.4, CHCl3);
IR (film) ν = 3330, 1726 cm− 1
;
1H NMR (600 MHz, CDCl3) δ 7.35–7.25 (m, 10H, Ar), 4.54, 4.50
(2d, J = 11.8 Hz, 2H, Bn), 4.54, 4.43 (2d, J = 11.8 Hz, 2H, Bn), 4.21
(dq, J = 8.7, 6.1 Hz, 1H, H-3′), 4.18 (m, 1H, H-4), 4.12 (m, 2H, OCH2CH3),
3.89 (ddd, J = 8.7, 8.0, 4.3 Hz, 1H, H-2), 3.63 (dd, J = 8.1, 3.9 Hz, 1H,
CHHOBn), 3.60–3.53 (m, 2H, H-5, CHHOBn), 2.59 (dd, J = 8.8, 4.3 Hz,
1H, H-2′), 2.11 (ddd, J =13.8, 9.1, 5.8 Hz, 1H, H-3), 1.99 (ddd, J = 13.8, 7.6,
The standard sequence of transformations of methyl 2-deoxy-D-riboside into 3.6 Hz, 1H, H-3), 1.25 (t, J = 7.1 Hz, 3H, OCH2CH3), 1.17 (d, J = 6.1 Hz, 3H,
nitrone 18 is described in the Supplementary Information.25 Compounds 21 CHCH3);
13C NMR (150 MHz, CDCl3) δ 172.3, 138.2, 138.1, 128.4, 128.4, 127.7,
127.7, 127.6, 127.4, 78.9, 73.2, 71.6, 68.1, 66.3, 60.4, 59.9, 55.6, 54.6, 32.6,
and 23 were obtained following procedures described for 7 and 8, whereas
compound 26 was obtained according to the procedure for 25.29
21.9, 14.2;
HRMS calcd for C25H34NO5 [M+H]+ 428.2437, found 428.2438.
Ethyl (2R,3S,3aR,5S,6S)-5-benzyloxy-6-benzyloxymethyl-2-
methylhexahydro-pyrrolo[1,2-b]isoxazole-3-carboxylate (6)
Nitrone 3 (1.50 g, 4.8 mmol) was dissolved in dry toluene (60 ml) in an argon
atmosphere and ethyl crotonate (3 eq. 1.65 g, 14.4 mmol) was added. The
Ethyl (2′S,3′R)-2′-(2R,4S,5S)-(4-benzyloxy-5-benzyloxymethyl-
pyrrolidin-2-yl)-3′-tert-butyldiphenylsilyloxy-butanoate (8)
Compound 7 (42 mg, ~ 0.1 mmol) was dissolved in dichloromethane (2.0 ml),
cooled to 0 °C and treated with Et3N (2 eq. 20 mg), and with tert-butyl(chloro)
diphenylsilane (1.2 eq. 33 mg, 1.2 mmol). The reaction mixture was stirred
overnight, and then filtered, dried (Na2SO4), evaporated, and purified on silica
gel using hexane/AcOEt 7:3 v/v as the eluent to afford 8, 66 mg (99%).
Colorless syrup; [α]D +36.9 (c 3.2, CHCl3);
reaction was carried out for 24 h at 40 °C. The reaction progress was monitored
by TLC and independently by NMR (the sample of the crude reaction mixture
was evaporated and examined). Subsequently, the solvent was evaporated and
the residue was purified on a silica gel column using hexane:AcOEt 7:3 v/v as
the eluent to afford 6, 2.0 g (95%).
Colorless syrup; [α]D +139 (c 3.2, CHCl3);
IR (film) ν 1725 cm−1
;
IR (film) ν = 1731 cm− 1
;
1H NMR (600 MHz, CDCl3) δ 7.74–7.20 (m, 20H, Ar), 4.51, 4.49
(2d, J = 12.2 Hz, 2H, Bn), 4.44, 4.36 (2d, J =12.0 Hz, 2H, Bn), 4.18 (m, 2H,
OCH2CH3), 3.93 (bs, 1H, H-4), 3.90 (m, 1H, H-3′), 3.56 (dd, J =9.5, 6.1 Hz,
1H, CHHOBn), 3.54 (m, 1H, H-2), 3.47 (m, 1H, CHHOBn), 3.34 (s, 1H, H-5),
2.53 (dd, J = 9.5, 4.9 Hz, 1H, H-2′), 1.86 (m, 1H, H-3a), 1.80 (m, 1H, H-3b),
1.27 (t, J = 7.1 Hz, 3H, OCH2CH3), 1.11 (d, J = 6.3 Hz, 3H, CHCH3), 1.04
(s, 9H, Si t-Bu).
1H NMR (600 MHz, CDCl3)
δ 7.35–7.26 (m, 10H, Ar), 4.61,
4.55 (2d, J = 11.8 Hz, 2H, Bn), 4.59, 4.49 (2d, J =12.2 Hz, 2H, Bn), 4.29 (m,
1H, H-3a), 4.28–4.24 (m, 2H, H-2, H-5), 4.19 (2dq, J =10.7, 7.1,
2H, OCH2CH3), 3.94 (t, J =9.1 Hz, 1H, CHHOBn), 3.77 (dd, J = 9.1, 4.8 Hz,
1H, CHHOBn), 3.40 (dt, J = 9.1, 4.8 Hz, 1H, H-6), 3.09 (dd, J = 10.2, 9.0 Hz,
1H, H-3), 2.09 (ddd, J = 13.7, 8.0, 6.8 Hz, 1H, H-4), 1.72 (ddd, J =13.7, 9.9,
4.3 Hz, 1H, H-4), 1.35 (d, J =5.8 Hz, 3H, CHCH3), 1.29 (t, J =7.1 Hz, 3H,
OCH2CH3).
13C NMR (150 MHz, CDCl3) δ 173.0, 138.5, 138.4, 136.0, 135.9, 134.8,
13C NMR (150 MHz, CDCl3) δ 170.0, 138.3, 138.3, 128.3, 128.3, 128.3, 134.2, 133.7, 129.7, 129.6, 128.3, 128.3, 127.6, 127.6, 127.5, 127.4, 127.3, 79.1,
73.2, 71.3, 68.7, 68.6, 60.5, 60.2, 59.8, 54.3, 35.2, 26.9, 19.7, 19.2, 14.3.
HRMS calcd for C41H52NO5Si [M+H]+ 666.3615, found 666.3617.
127.8, 127.5, 127.5, 127.3, 78.1, 73.5, 71.8, 71.6, 70.9, 68.5, 64.2, 60.8, 57.1,
33.1, 16.5, 14.2.
HRMS calcd for C25H32NO5 [M+H]+ 426.2280, found 426.2284.
(2S,3S,5R,6S,1′R)-3-Benzyloxy-2-benzyloxymethyl-6-(1′-tert-
butyldiphenylsilyloxyethyl)-1-azabicyclo[3.2.0]heptan-7-one (9)
Compound 8 (1.5 g, 2.30 mmol) was dissolved in dry THF (46 ml), cooled
Ethyl (2′S,3′R)-2′-(2R,4S,5S)-(4-benzyloxy-5-benzyloxymethyl-
pyrrolidin-2-yl)-3′-hydroxy-butanoate (7)
Adduct 6 (42 mg, 0.1 mmol) in acetonitrile (2.0 ml) was treated with 10% HCl to − 20 °C, and treated with (1.1 eq. 1.3 ml) of tert-butyl magnesium chloride
(0.2 ml) and Zn powder (10 eq. 65 mg, 1.0 mmol). The mixture was stirred for (2M in Et2O). The reaction progress was monitored by TLC. After about
1 h at room temperature. The reaction progress was monitored by TLC. After 15 min, a saturated solution of Na2CO3 was added and the reaction mixture
1 h an additional portion of acid and Zn powder was added to complete the was extracted with AcOEt. The extract was dried (Na2SO4), evaporated, and
reaction. Subsequently, the solution of 7 was filtered and the precipitate was purified on silica gel using hexane/AcOEt 7:3 v/v as the eluent to afford 9,
washed with AcOEt. The mixture was then neutralized with sodium 1.35 g (95%).
The Journal of Antibiotics

Synthesis of Thienamycin
M Pieczykolan et al
4
Colorless syrup; [α]D +100.6 (c 0.4, CHCl3);
IR (film) ν = 1760 cm−1
evaporated, and purified on a silica gel column using hexane/AcOEt 1:1 v/v
as the eluent to afford 12, 70 mg (48%).
;
1H NMR (600 MHz, CDCl3) δ 7.69–7.22 (m, 20H, Ar), 4.56, 4.50
(2d, J = 12.0 Hz, 2H, Bn), 4.53, 4.47 (2d, J = 11.8 Hz, 2H, Bn), 4.35
(td, J = 5.3, 3.2 Hz, 1H, H-3), 4.17 (quint. J = 6.5 Hz, 1H, H-1′),
4.05 (q, J =6.3 Hz, 1H, H-2), 3.72 (ddd, J =8.0, 6.1, 2.0 Hz, 1H, H-5), 3.64
(dd, J =9.6, 6.3 Hz, 1H, CHHOBn), 3.55 (dd, J =9.6, 6.3 Hz, 1H, CHHOBn),
2.85 (dd, J = 6.5, 2.0 Hz, 1H, H-6), 2.24 (ddd, J = 13.3, 6.1, 3.2 Hz, 1H, H-4a),
1.58 (ddd, J = 13.3, 8.0, 5.3 Hz, 1H, H-4b), 1.16 (d, J = 6.5 Hz, 3H, CHCH3),
1.04 (s, 9H, t-Bu);
Colorless syrup; [α]D +114.3 (c 3.3, CHCl3);
IR (film) ν =3475; 1757 cm−1
;
1H NMR (600 MHz, CDCl3) δ 7.75–7.27 (m, 10H, Ar), 4.31 (quint.,
J = 6.2 Hz, 1H, H-1′), 3.97 (t, J = 3.6 Hz, 1H, H-2), 3.87 (dd, J = 11.3, 3.6 Hz,
1H, CHHOH), 3.80 (ddd, J = 7.9, 7.0, 2.0 Hz, 1H, H-5), 3.74 (dd, J = 11.3,
3.6 Hz, 1H, CHHOH), 3.15 (dd, J = 6.2, 2.0 Hz, 1H, H-6), 2.65 (dd, J = 18.7,
7.0 Hz, 1H, H-4), 2.33 (dd, J = 18.7, 7.9 Hz, 1H, H-4), 1.71 (s, 1H, OH), 1.23
(d, J = 6.2 Hz, 3H, CHCH3), 1.06 (s, 9H, t-Bu).
13C NMR (150 MHz, CDCl3) δ 176.7, 138.3, 138.0, 135.9, 135.8, 134.1,
133.6, 129.7, 129.6, 128.4, 128.3, 127.7, 127.6, 127.6, 127.5, 127.5, 127.4, 84.1,
73.2, 72.2, 68.0, 68.0, 64.5, 61.3, 54.7, 36.2, 26.9, 22.4, 19.3;
13C NMR (150 MHz, cdcl3) δ 214.6, 174.1, 135.8, 135.8, 133.8, 133.3, 130.0,
129.8, 127.7, 127.6, 68.6, 67.5, 63.5, 62.4, 52.0, 41.9, 26.8, 22.4, 19.3.
HRMS calcd for C25H31NO4SiNa [M+Na]+ 460.1920, found 460.1925.
HRMS calcd for C39H45NO4SiNa [M+Na]+ 642.3016, found 642.3018.
(5R,6S,1′R)-6-(1′-tert-Butyldiphenylsilyloxyethyl)-7-oxo-1-
azabicyclo[3.2.0]hept-2-ene-2-carbaldehyde (13)
(2S,3S,5R,6S,1′R)-6-(1′-tert-Butyldiphenylsilyloxyethyl)-3-hydroxy-
2-hydroxymethyl-1-azabicyclo[3.2.0]heptan-7-one (11)
Oxalyl chloride (2 eq. 84 mg, 0.66 mmol) was dissolved in dry DCM (2.4 ml).
The solution was cooled to − 78 °C and DMSO (4eq. 103 mg, 1.32 mmol) in
dry DCM (5.5 ml) was added. After 30 min substrate 11 (145 mg, 0.33 mmol)
in dry DCM (1.7 ml) was added and after another 30 min Et3N (8eq. 267 mg,
2.64 mmol) was added and the reaction mixture was allowed to reach room
temperature. The mixture was then extracted with AcOEt, dried (Na2SO4),
evaporated and purified on a silica gel column using hexane/AcOEt 1:1 v/v as
the eluent to afford 13, 30 mg (22%).
Compound 9 (0.20 g, 0.33 mmol), was dissolved in dry DCM (5.5 ml) The
solution was cooled to − 78 °C, and treated with (3 eq, 1.0. mmol 1.0 ml) of
BCl3 (1M in DCM). The reaction progress was monitored by TLC. After about
20 min a saturated solution of Na2CO3 (10 ml) was added and the mixture was
allowed to reach room temperature. Subsequently, the mixture was extracted
with AcOEt. The extract was dried (Na2SO4), evaporated and purified on silica
gel using hexane/AcOEt 6:4v/v as the eluent to afford 11, 0.13 g (93%).
Colorless syrup; [α]D +79.7 (c 2.0, CHCl3);
Colorless syrup; [α]D +47.5 (c 1.8, CHCl3);
IR (film) ν 3417; 1738 cm− 1
;
IR (film) ν =1779; 1691 cm−1
;
1H NMR (600 MHz, CDCl3) δ 7.71–7.35 (m, 10H, Ar), 4.78 (bt, 1H, H-3),
4.22 (quint., J = 6.1 Hz, 1H, H-1′), 3.89 (dt, J = 6.7, 4.7 Hz, 1H, C-2), 3.85
(m, 1H, H-5), 3.85 (dd, J = 11.1, 4.3 Hz, CHHOH), 3.78 (dd, J =11.1, 6.7 Hz,
1H, CHHOH), 2.98 (s, 2H, OH), 2.86 (dd, J = 6.1, 1.9 Hz, 1H, H-6), 2.19
(ddd, J =13.6, 5.6, 2.3 Hz, 1H, H-4), 1.65 (ddd, J = 13.6, 9.0, 5.2 Hz, 1H, H-4),
1.15 (d, J = 6.1 Hz, 3H, CHCH3), 1.05 (s, 9H, t-Bu).
1H NMR (600 MHz, CDCl3) δ 9.58 (s, 1H, CHO), 7.74–7.35 (m, 10H, Ar),
6.44 (t, J = 3.1 Hz, 1H, H-3), 4.19 (quint, J = 6.3 Hz, 1H, H-1′), 4.03
(ddd, J = 10.0, 7.9, 3.1 Hz, 1H, H-5), 3.22 (dd, J = 6.3, 3.1 Hz, 1H, H-6),
2.87 (ddd, J = 20.1, 10.0, 3.1 Hz, 1H, H-4a), 2.80 (ddd, J = 20.1, 7.9, 3.1 Hz,
1H, H-4b), 1.21 (d, J =6.3 Hz, 3H, CHCH3), 1.06 (s, 9H, t-Bu).
13C NMR (150 MHz, CDCl3)
δ 182.5, 176.4, 144.1, 137.0, 135.8,
13C NMR (150 MHz, CDCl3) δ 177.1, 135.9, 135.8, 134.2, 133.4, 129.8,
129.7, 127.7, 127.5, 79.4, 67.5, 64.5, 62.5, 61.5, 54.9, 40.4, 26.9, 22.3, 19.3.
HRMS calcd for C25H33NO4SiNa [M+Na]+ 462.2077, found 462.2072
135.8, 133.7, 133.3, 129.9, 129.9, 127.7, 127.7, 68.0, 67.7, 55.1, 35.9, 26.9,
22.2, 19.3.
HRMS calcd for C25H29NO3NaSi [M+Na]+ 442.1814, found 442.1818.
(2S,3S,5R,6S,1′R)-3-Benzyloxy-6-(1′-tert-butyldiphenylsilyl-
oxyethyl)-2-hydroxymethyl-1-azabicyclo[3.2.0]heptan-7-one (10)
Compound 9 (0.12 g, 0.20 mmol), was dissolved in dry DCM (5.5 ml), cooled
to -78 °C, and treated with freshly prepared BCl3•SMe2 (5 eq, 1.0 mmol 1.0 ml)
(BCl3 (1 M in DCM) and SMe2 (6 eq. 1.20 mmol 0.1 ml)). The reaction
progress was monitored by TLC. The reaction starts at -20 °C and should be
terminated when the temperature reaches − 15 °C. Subsequently, a saturated
solution of Na2CO3 (10 ml) was added. When the reaction reached room
temperature, the mixture was extracted with AcOEt. The extract was dried
(Na2SO4), evaporated and purified on silica gel using hexane/AcOEt 6:4v/v as
the eluent to afford 10 (70 mg, 66%), and 11, 16 mg (18%).
(2S,3S,5R,6S,1′R)-6-(1′-tert-Butyldiphenylsilyloxyethyl)-3-hydroxy-
2-trityloxymethyl-1-azabicyclo[3.2.0]heptan-7-one (14)
Compound 11 (44 mg, 0.1 mmol), was dissolved in dry DCM (1.0 ml)
and treated with Et3N (2 eq. 20 mg, 0.2 mmol). The solution was cooled to
0 °C and treated with TrCl (1.3 eq. 36 mg, 0.13 mmol) in dry DCM (0.5 ml).
The reaction mixture was left for 24 h at room temperature. Subsequently, the
solvent was evaporated and the residue was purified on silica gel using hexane/
AcOEt 7:3 v/v as the eluent to afford 14 (63 mg, 92%).
Colorless syrup, [α]D+78.3 (c, 0.55, CHCl3);
IR (film) ν =3478; 1758 cm−1
;
1H NMR (500 MHz, CDCl3) δ 7.68–7.24 (m, 25 H, Ar), 4.80 (t, J = 5.3 Hz,
1H, H-3), 4.14 (quint., J = 6.2 Hz, 1H, H-1′), 4.03 (dt, J = 8.1, 5.3 Hz, 1H,
H-2), 3.86 (ddd, J = 8.3, 5.7, 1.9 Hz, 1H, H-5), 3.46 (dd, J = 9.4, 5.3 Hz, 1H,
CHHOTr), 3.10 (dd, J = 9.4, 8.1 Hz, 1H, CHHOTr), 2.85 (dd, J = 6.2, 1.9 Hz,
1H, H-6), 2.20 (ddd, J = 13.6, 5.7, 2.1 Hz, 1H, H-4a), 1.70 (ddd, J =13.6, 8.3,
5.3 Hz, 1H, H-4b), 1.13 (d, J =6.2 Hz, 3H, CHCH3), 0.99 (s, 9H, t-Bu);
13C NMR (126 MHz, CDCl3) δ 176.4, 143.2, 135.8, 135.8, 134.1, 133.4,
129.7, 129.6, 128.3, 128.1, 127.6, 127.5, 127.3, 87.3, 78.8, 67.8, 64.6, 62.3, 61.0,
55.1, 39.5, 26.9, 22.3, 19.3;
Compound 10, colorless syrup, [α]D +98.7 (c 1.5, CHCl3);
IR (film) ν = 3438; 1757 cm− 1
;
1H NMR (600 MHz, CDCl3) δ 7.73–7.27 (m, 15H, Ar), 4.58, 4.44
(2d, J = 11.7 Hz, 2H, Bn), 4.43 (m, 1H, H-3), 4.22 (quint., J = 6.3 Hz, 1H,
H-1′), 3.99 (q, J = 5.8 Hz, 1H, H-2), 3.75–3.69 (m, 3H, H-5, CH2OH), 2.89
(dd, J =6.3, 2.0 Hz, 1H, H-6), 2.27 (ddd, J = 13.6, 6.2, 3.1 Hz, 1H, H-4), 2.12
(s, 1H, OH), 1.65 (ddd, J = 13.6, 7.7, 5.8 Hz, 1H, H-4), 1.20 (d, J = 6.3 Hz, 3H,
CHCH3), 1.07 (s, 9H, t-Bu);
13C NMR (150 MHz, CDCl3) δ 176.7, 137.3, 135.8, 135.8, 134.0, 133.5,
129.7, 129.7, 128.6, 128.3, 127.6, 127.5, 127.5, 84.9, 72.1, 67.9, 65.0, 62.7, 61.1,
54.5, 35.8, 26.8, 22.3, 19.3.
HRMS calcd for C44H47NO4KSi [M+K]+ 720.2911, found 720.2917.
HRMS calcd for C32H39NO4NaSi [M+Na]+ 552.2546, found 552.2542.
(2S,3S,5R,6S,1′R)-6-(1′-tert-Butyldiphenylsilyloxyethyl)-3-
methanesulfonyloxy-2-trityloxymethyl-1-azabicyclo[3.2.0]heptan-7-
one (15)
(2S,5R,6S,1′R)-6-(1′-tert-Butyldiphenylsilyloxyethyl)-2-
Compound 14 (0.37 g, 0.55 mmol), was dissolved in dry DCM (5.5 ml), Et3N
(3 eq. 0.17 g, 1.65 mmol) was added and the solution was cooled to 0 °C. Next,
MsCl (1.1 eq. 0.07 g, 0.60 mmol) was added. The reaction was allowed to reach
room temperature. The reaction progress was monitored by TLC (DCM), after
hydroxymethyl-1-azabicyclo[3.2.0] heptane-3,7-dione (12)
Compound 11 (140 mg, 0.33 mmol) was dissolved in dry DCM (6.6 ml) and
treated with MnO2 (30eq. 860 mg, 9.9 mmol). The reaction was carried out for
24 h at room temperature. The reaction progress was monitored by TLC.
Subsequently, the mixture was filtered through a short pad of Celite, ca. 1 h TLC shows disappearance of substrate. The reaction mixture was
The Journal of Antibiotics

Synthesis of Thienamycin
M Pieczykolan et al
5
extracted with a saturated Na2CO3 solution, dried (Na2SO4), evaporated and
purified on a silica gel column using hexane/AcOEt 1:1 v/v as an eluent to
afford 15, 410 mg (98%).
HRMS calcd for C26H31NO4NaSi [M+Na]+ 472.1920, found 472.1919.
(2S,3S)-3-Benzyloxy-2-(p-methoxybenzyloxymethyl)-3,4-dihydro-
2H-pyrrole-1-oxide (18)
Nitrone 18 was synthesized according to the standard procedure described in
Colorless syrup, [α]D +63.6 (c 0.76 CHCl3);
IR (film) ν =1765 cm− 1
;
1H NMR (500 MHz, CDCl3) δ 7.67–7.21 (m, 25 H, Ar), 5.38 (td, J = 5.6,
3.4 Hz, 1H, H-3), 4.13 (m, 1H, H-1′), 4.10 (m, 1H, H-2), 3.80 (ddd, J = 7.5,
6.2, 2.2 Hz, 1H, H-5), 3.31 (dd, J = 9.6, 5.1 Hz, 1H, CHHOTr), 3.11
(dd, J = 9.6, 6.5 Hz, 1H, CHHOTr), 2.95 (dd, J = 6.8, 2.2 Hz, 1H, H-6), 2.73
(s, 3H, OMs), 2.56 (ddd, J = 13.8, 6.2, 3.4 Hz, 1H, H-4a), 1.93 (ddd, J = 13.8,
7.5, 5.6 Hz, 1H, H-4b), 1.18 (d, J = 6.2 Hz, 3H, CHCH3), 1.02 (s, 9H, Sit-Bu);
13C NMR (125 MHz, CDCl3) δ 176.2, 143.5, 135.8, 135.7, 133.9, 133.4,
129.9, 129.7, 128.6, 127.9, 127.7, 127.6, 127.2, 87.4, 83.9, 68.0, 65.1, 61.6, 60.6,
54.6, 38.2, 38.0, 26.9, 22.3, 19.3.
Supplementary Information.
Colorless syrup; [α]D +21.2 (c 1.5, CHCl3);
IR (film) ν = 3098 cm−1
;
1H NMR (600 MHz, CDCl3) δ 7.36–6.81 (m, 10H, Ar), 6.86 (m, 1H, H-2),
4.59, 4.56 (2d, J =11.8 Hz, 2H, Bn), 4.52, 4.48 (2d, J = 11.6 Hz, 2H, OPMB),
4.46 (dt, J = 7.1, 4.8 Hz, 1H, H-3), 4.09 (m, 1H, H-2), 4.06 (dd, J = 9.6, 6.2 Hz,
1H, CHHOPMB), 4.99 (dd, J = 9.6, 2.7 Hz, 1H, CHHOPMB), 3.79 (s, 3H,
OCH3), 2.83 (dddd, J =18.0, 7.1, 2.5, 1.3 Hz, 1H, H-4a), 2.75 (dddd, J = 18.0,
4.5, 2.7, 1.3 Hz, 1H, H-4b).
HRMS calcd for C45H49NO6SSiNa [M+Na]+ 782.2948, found 782.2926.
13C NMR (150 MHz, CDCl3) δ 159.1, 137.4, 133.1, 130.0, 129.3, 128.5,
127.9, 127.5, 113.7, 74.3, 73.6, 73.3, 72.2, 64.5, 55.2, 35.0.
HRMS calcd for C20H23NO4Na [M+Na]+ 364.1525, found 364.1535.
(2S,3S,5R,6S,1′R)-6-(1′-tert-Butyldiphenylsilyloxyethyl)-3-methane-
sulfonyloxy-2-hydroxymethyl-1-azabicyclo[3.2.0]heptan-7-one (16)
Compound 15 (0.20 g, 0.26 mmol), was dissolved in dry DCM (2.6 ml) The
solution was cooled to − 78 °C, and treated with (3 eq. 0.78 mmol, 0.78 ml) of
BCl3 (1M in DCM). The reaction progress was monitored by TLC. When the
reaction reached room temperature, TLC showed disappearance of the
substrate. Next, a saturated solution of Na2CO3 (5 ml) was added and
the mixture was extracted with AcOEt. The extract was dried (Na2SO4),
evaporated and purified on silica gel using hexane/AcOEt 4:6 v/v as an eluent to
afford 16, 0.125 g (93%).
Ethyl (2R,3S,3aR,5S,6S)-5-(benzyloxy)-6-(p-
methoxybenzyloxymethyl)-2-methylhexahydro-pyrrolo[1,2-b]
isoxazole-3-carboxylate (19)
Nitrone 18 (2.0 g, 5.85 mmol) was dissolved in dry toluene (73 ml) in an argon
atmosphere, and ethyl crotonate (3 eq. 2.0 g, 17.55 mmol) was added. The
reaction was carried out for 24 h at 40 °C while its progress was monitored by
TLC and independently by NMR (a sample of the crude reaction mixture was
evaporated and examined). Subsequently, the solvent was evaporated and the
residue was purified on a silica gel column using hexane:AcOEt 7:3 v/v as the
eluent to afford 19, 2.4 g (96%).
Colorless syrup, [α]D +87.1 (c 1.23 CHCl3);
IR (film) ν = 3449, 1760 cm− 1
;
1H NMR (600 MHz, CDCl3) δ 7.71–7.37 (m, 10H, Ar), 5.49 (td, J = 4.7,
1.8 Hz, 1H, H-3), 4.21 (quint., J = 6.1 Hz, 1H, H-1′), 4.05 (ddd, J = 7.8, 6.3,
4.7 Hz, 1H, H-2), 3.81 (ddd, J = 9.0, 5.5, 2.0 Hz, 1H, H-5), 3.72 (dd, J = 11.3,
6.3 Hz, 1H, CHHOH), 3.67 (dd, J = 11.3, 7.8 Hz, 1H, CHHOH), 3.08 (s, 3H,
OMs), 2.91 (dd, J = 6.1, 2.0 Hz, 1H, H-6), 2.47 (ddd, J = 14.1, 5.5, 1.8 Hz,
1H, H-4a), 1.81 (ddd, J = 14.1, 9.0, 4.7 Hz, 1H, H-4b), 1.16 (d, J = 6.1 Hz,
3H, CH3), 1.04 (s, 9H, tert-Bu);
Colorless syrup; [α]D +152.6 (c 0.64, CHCl3);
IR (film) ν = 1729 cm−1
;
1H NMR (600 MHz, CDCl3)
δ 7.31–6.73 (m, 9H, Ar), 4.54, 4.44
(2d, J = 12.2 Hz, 2H, OBn), 4.50, 4.44 (2d, J = 11.5 Hz, 2H, OPMB), 4.26
(m, 1H, H-3a), 4.21 (m, 2H, H-2, H-5), 4.30 (m, 2H, CH2CH3), 3.85
(t, J = 9.1 Hz, CHHOPMB), 3.77 (s, 3H, OCH3), 3.70 (dd, J = 9.1, 5.0 Hz,
1H, CHHOPMB), 3.35 (m, 1H, H-6), 3.05 (bt, J = 9.1, 10.0 Hz, 1H, H-3), 2.06
(dd, J = 13.5, 7.0 Hz, 1H, H-4a), 1.68 (ddd, J =13.5, 9.9, 4.3.0 Hz, 1H, H-4b),
1.31 (d, J = 5.8 Hz, 3H, CHCH3), 1.25 (t, J = 7.1 Hz, 3H, OCH2CH3).
13C NMR (150 MHz, CDCl3) δ: 169.9, 159.1, 138.3, 129.5, 128.3, 128.2,
127.4, 127.3, 113.7, 78.1, 73.2, 71.8, 71.6 70.9, 68.1, 64.2, 60.8, 57.0, 55.2, 33.2,
16.4, 14.2;
13C NMR (150 MHz, CDCl3) δ 176.6, 135.8, 135.8, 133.9, 133.3, 129.9,
129.8, 127.7, 127.6, 85.6, 67.3, 64.4, 62.8, 60.2, 54.3, 38.8, 38.3, 26.8, 22.3, 19.3.
HRMS calcd for C26H35NO6NaSiS [M+Na]+ 540.1852, found 540.1847.
Methyl (5R,6S,1′R)-6-(1′-tert-butyldiphenylsilyloxyethyl)-7-oxo-1-
azabicyclo[3.2.0]hept-2-ene-2-carboxylate (17)
Compound 16 (0.12 g, 0.23 mmol) was dissolved in acetone (2.3 ml) and
cooled to 0 °C. Subsequently aqueous 5% v/v NaHCO3 solution (0.57 ml) was
added, followed with potassium bromide (2.7 mg, 0.023 mmol) and TEMPO
(1.1 eq. 40 mg, 0.25 mmol). Under stirring, a 5% aqueous NaOCl solution
(0.46 ml) was added dropwise. After 1 h, an additional portion of 5% NaOCl
solution in water (0.46 ml) was added, and stirring was continued at 0 °C while
the progress of the reaction was monitored by TLC. The reaction was
HRMS calcd for C26H34NO6 [M+H]+ 456.2386, found 456.2397.
Ethyl (2R,4S,5S,2′S,3′R)-2′-[4-benzyloxy-5-(p-methoxybenzyl-
oxymethyl)-pyrrolidin-2-yl]-3′-hydroxy-butanoate (20)
Adduct 19 (0.18 g, 0.4 mmol) in acetonitrile (8 ml) was treated with 10% HCl
(0.8 ml) and Zn powder (10 eq. 0.26 g, 4.0 mmol). The mixture was stirred for
1 h at room temperature. The reaction progress was monitored by TLC, and
after 1 h an additional portion of acid and Zn powder was added to complete
the reaction. Subsequently, the solution was filtered and the precipitate
was washed with AcOEt. The mixture was then neutralized with sodium
bicarbonate and extracted with AcOEt. The extract was dried (Na2SO4),
evaporated to afford 20, 0.18 g (99%), which was used in the next step without
chromatographic purification.
terminated by the addition of
a 5% NaHCO3 solution. Acetone was
then removed on a rotary evaporator and the residue was suspended in
dichloromethane (5 ml), treated with a saturated solution of NH4Cl (5 ml) and
the mixture was extracted with dichloromethane. The combined organic
extracts were dried, concentrated, dissolved in Et2O (5 ml), and treated with
an excess of diazomethane in ether, then evaporated. The residue was purified
by column chromatography on silica gel, hexane/EtOAc (10/1, then 8/2) to give
compound 17 as colorless oil, 95 mg (92%).
Colorless syrup; [α]D +24.1 (c 1.1, CHCl3);
Colorless syrup, [α]D +88.7 (c 1.49 CHCl3);
IR (film) ν = 3331; 1727 cm− 1
;
IR (film) ν = 1784, 1733 cm− 1
;
1H NMR (600 MHz, CDCl3)
δ 7.35–6.84 (m, 9H, Ar), 4.53, 4.43
1H NMR (600 MHz, CDCl3): δ 7.70–7.36 (m, 10H, Ar), 6.42 (dd, J = 3.1,
2.6 Hz, 1H, H-3), 4.16 (dq, J = 7.4, 6.2 Hz, 1H, H-1′), 3.99 (ddd, J = 9.9, 8.3,
3.0 Hz, 1H, H-5), 3.81 (s, 3H, OCH3), 3.21 (dd, J = 7.4, 3.0 Hz, 1H, H-6), 2.78
(ddd, J = 19.2, 9.9, 3.1 Hz, 1H, H-4a), 2.72 (ddd, J = 19.2, 8.3, 2.6 Hz, 1H,
H-4b), 1.23 (d, J = 6.2 Hz, 3H, CH3), 1.05 (s, 9H, tert-Bu);
(2d, J =11.9 Hz, 2H, OBn), 4.47, 4.43 (2d, J = 11.3 Hz, 2H, OPMB),
4.21 (dq, J = 8.8, 6.1 Hz, 1H, CHCH3), 4.17 (m, 1H, H-4), 4.12 (m, 2H,
OCH2CH3), 3.86 (ddd, J = 9.1, 7.5, 4.4 Hz, 1H, H-2), 3.79 (s, 3H, OCH3), 3.59
(dd, J = 8.6, 4.6 Hz, 1H, CHHOPMB), 3.56 (m, 1H, CHHOPMB), 3.51 (m, 1H,
H-5), 2.58 (dd, J = 8.8, 4.4 Hz, 1H, CHCOOEt), 2.10 (ddd, J = 13.7, 9.1, 5.9 Hz,
1H, H-3a), 1.98 (ddd, J = 13.7, 7.5, 3.4 Hz, 1H, H-3b), 1.24 (t, J = 7.1 Hz, 3H,
OCH2CH3), 1.17 (d, J =6.1 Hz, 3H, CHCH3).
13C NMR (150 MHz, CDCl3): δ 176.6, 161.0, 135.8, 135.8, 135.2, 133.7,
133.4, 131.4, 129.9, 129.8, 127.7, 127.7, 68.3, 67.5, 55.7, 52.3, 35.8, 26.9,
22.2, 19.2.
The Journal of Antibiotics

Synthesis of Thienamycin
M Pieczykolan et al
6
13C NMR (151 MHz, CDCl3) δ 172.3, 159.2, 138.2, 130.1, 129.3, 128.3,
127.6, 127.3, 113.8, 78.9, 72.8, 71.5, 67.7, 66.3, 60.4, 59.8, 55.6, 55.2, 54.6, 32.6,
21.8, 14.1.
Colorless syrup; [α]D +62.1 (c 1.0, CHCl3);
IR (film) ν =3452; 1758 cm−1
1H NMR (600 MHz, CDCl3)
;
δ
7.39–7.27 (m, 5H, Ar), 4.61, 4.47
HRMS calcd for C26H36NO6 [M+H]+ 458.2543, found 458.2557.
(2d, J = 11.8 Hz, 2H, OBn), 4.44 (dt, J = 3.2, 5.8 Hz, 1H, H-3), 4.18 (quint.,
J = 6.2 Hz, 1H, H-1′), 3.99 (q, J = 5.8 Hz, 1H, H-2), 3.87 (ddd, J = 7.8, 6.4,
2.1 Hz, 1H, H-5), 3.72 (bd, J = 5.8 Hz, 2H, CH2OH), 2.79 (dd, J = 6.2, 2.1 Hz,
1H, H-6), 2.32 (ddd, J = 13.6, 6.4, 3.2 Hz, 1H, H-4a), 1.69 (ddd, J =13.6, 7.8,
5.8 Hz, 1H, H-4b), 1.22 (d, J = 6.2 Hz, 3H, CHCH3), 0.88 (s, 9H, Sit-Bu), 0.07
(s, 6H, Si(CH3)2);
Ethyl (2R,4S,5S,2′S,3′R)-2′-[4-benzyloxy-5-(p-methoxy-
benzyloxymethyl)-pyrrolidin-2-yl]-3′-tert-butyldimethylsilyloxy-
butanoate (21)
Compound 20 (2.0 g, 4.35 mmol) was dissolved in dichloromethane (43 ml),
cooled to 0 °C, treated with imidazole (2 eq. 0.59 g, 8.70 mmol), and
tert-butyldimethylchlorosilane (1.2 eq. 0.79 g 5.22 mmol) in dichloromethane
(5 ml). The reaction mixture was stirred overnight, then it was filtered, dried,
evaporated and purified on silica gel using hexane/AcOEt 7:3 v/v as the eluent
to afford 21, 2.4 g (98%).
13C NMR (150 MHz, CDCl3) δ 177.1, 137.3, 128.6, 128.0, 127.5, 84.9, 72.3,
66.1, 65.1, 62.7, 61.1, 53.8, 35.9, 25.6, 22.6, 17.9, − 4.3, − 5.0;
HRMS calcd for C22H35N4NaSi [M+Na]+ 428.2233, found 428.2234.
Methyl (2R,3S,5R,6S,1′R)-3-(benzoyloxy)-6-(1′-(tert-
butyldimethylsilyloxyethyl)-7-oxo-1-azabicyclo[3.2.0]heptane-2-
carboxylate (25)
Colorless syrup; [α]D +14.1 (c 0.61, CHCl3);
IR (film) ν = 1725 cm−1
;
1H NMR (600 MHz, CDCl3)
δ 7.35–6.81 (m, 9H, Ar), 4.52, 4.44,
Compound 5 (0.10 g, 0.25 mmol) was dissolved in acetone (2.5 ml) and cooled
to 0 °C. Subsequently, an aqueous saturated sodium bicarbonate solution
(0.75 ml) was added, followed by potassium bromide (0.1 eq. 3 mg,
0.025 mmol) and TEMPO (1.1 eq. 43 mg, 0.27 mmol). Under stirring,
a 5% aqueous NaOCl solution (0.6 ml) was added dropwise. After 1 h,
additional portion of NaOCl 5% solution in water (0.6 ml) was added, and
stirring was continued at 0 °C while the progress of the reaction was monitored
by TLC. The reaction was terminated by the addition of a 5% NaHCO3
solution. Acetone was then removed on a rotary evaporator and the residue was
suspended in dichloromethane (5 ml), treated with a saturated solution of
NH4Cl (5 ml) and the mixture was extracted with dichloromethane. The
combined organic extracts were dried, concentrated, dissolved in Et2O (5 ml),
and treated with excess of diazomethane in ether, then evaporated. The residue
was purified by column chromatography on silica gel, hexane/EtOAc (10/1 then
7/3) to give compound 25 as a colorless oil, 47 mg (84%). The spectral and
analytical data were identical with those reported by us recently.10
Colorless syrup, [α]D +80.6 (c 1.0, CHCl3);
(2d, J = 12.0 Hz, 1H, OBn), 4.44 (s, 2H, OPMB), 4.13 (m, 2H, OCH2CH3),
4.08 (m, 1H, H-4), 4.00 (quint., J = 6.3 Hz, 1H, H-3′), 3.78 (s, 3H, OCH3),
3.67 (bq, J = 8.2 Hz, 1H, H-2), 3.59 (dd, J = 9.3, 5.5 Hz, 1H, CHHOPMB),
3.49 (dd, J =9.3, 7.3 Hz, 1H, CHHOPMB), 3.43 (m, 1H, H-5), 2.46
(dd, J = 8.2, 6.3 Hz, 1H, H-2′), 2.09 (ddd, J = 13.5, 7.2, 3.0 Hz, 1H, H-3a),
1.65 (ddd, J = 13.5, 8.6, 5.5 Hz, 1H, H-3b), 1.24 (t, J = 7.1 Hz, 3H, OCH2CH3),
1.16 (d, J = 6.3 Hz, 3H, CHCH3), 0.88 (s, 9H, Sit-Bu), 0.06 (s, 3H, SiCH3), 0.05
(s, 3H, SiCH3);
13C NMR (150 MHz, CDCl3) δ 173.1, 159.1, 138.6, 130.6, 129.3, 128.3,
127.4, 127.3, 113.7, 79.3, 72.9, 71.4, 68.5, 68.1, 60.5, 60.2, 60.1, 55.2, 54.5, 36.3,
25.8, 21.2, 18.0, 14.3, −4.5, − 4.8;
HRMS calcd for C32H50NO6Si [M+H]+ 572.3407, found 572.3414.
(2S,3S,5R,6S,1′R)-3-Benzyloxy-6-(1′-tert-butyldimethyl-
silyloxyethyl)-2-(p-methoxybenzyloxy-methyl)-1-azabicyclo[3.2.0]
heptan-7-one (23)
Compound 21 (2.34 g, 4.10 mmol), was dissolved in dry THF (82 ml), cooled
to − 20 °C, and treated with (1.1 eq 2.30 ml) of tert-butyl magnesium chloride
(2 M in Et2O). The reaction progress was monitored by TLC. After ca. 15 min
a saturated solution of Na2CO3 was added and the reaction mixture was
extracted with AcOEt. The extract was dried (Na2SO4), evaporated and purified
on silica gel using hexane/AcOEt 7:3 v/v as the eluent to afford 23,
1.68 g (78%).
IR (film) ν =1766 cm− 1
;
1H NMR (600 MHz, CDCl3) δ 7.37–7.24 (m, 5H, Ar), 4.61 (d, J = 5.6 Hz,
1H, H-2), 4.59 (td, J =5.6, 3.1 Hz, 1H, H-3), 4.55, 4.54 (2d, J = 12.1 Hz, 2H,
Bn), 4.22 (quit., J = 6.3 Hz, 1H, H-1′), 4.06 (ddd, J = 7.8, 6.2, 2.1 Hz, 1H, H-5),
3.70 (s, 3H, OCH3), 2.82 (dd, J = 6.3, 2.1 Hz, 1H, H-6), 2.35 (ddd, J = 13.4,
6.2, 3.1 Hz, 1H, H-4a), 1.66 (ddd, J = 13.4, 7.8, 5.6 Hz, 1H, H-4b), 1.24
(d, J = 6.3 Hz, 3H, CHCH3), 0.89 (s, 9H, t-Bu), 0.08 (s, 3H, SiCH3), 0.08
(s, 3H, SiCH3);
Colorless syrup; [α]D +82.6 (c 1.7, CHCl3);
IR (film) ν = 1760 cm−1
;
13C NMR (150 MHz, CDCl3) δ 175.8, 168.5, 137.3, 128.4, 127.8, 127.5, 85.4,
72.5, 66.2, 65.3, 63.6, 55.2, 52.0, 36.0, 25.6, 22.6, 17.9, − 4.3, − 5.0.
HRMS calcd for C23H35NO5NaSi [M+H]+ 456.2182, found 456.2184.
1H NMR (600 MHz, CDCl3)
δ 7.35–6.81 (m, 9H, Ar), 4.55, 4.50
(2d, J =12.0 Hz, 2H, OBn), 4.51, 4.45 (2d, J = 11.5 Hz, 2H, OPMB),
4.36 (td, J = 5.2, 3.1 Hz, 1H, H-3), 4.16 (quint. J = 6.2 Hz, 1H, H-1′),
4.04 (q, J = 5.2 Hz, 1H, H-2), 3.84 (ddd, J = 8.1, 6.0, 2.0 Hz, 1H, H-5),
3.79 (s, 3H, OCH3), 3.65 (dd, J = 9.7, 6.8 Hz, 1H, CH2OPMB), 3.56
(dd, J = 9.7, 6.0 Hz, 1H, CH2OPMB), 2.77 (dd, J = 6.2, 2.0 Hz, 1H, H-6),
2.30 (ddd, J = 13.3, 6.0, 3.1 Hz, 1H, H-4a), 1.59 (ddd, J = 13.3, 8.0, 5.2 Hz, 1H,
H-4b), 1.22 (d, J = 6.2 Hz, 3H, CHCH3), 0.87 (s, 9H, Sit-Bu), 0.06 (s, 6H Si
(CH3)2);
CONFLICT OF INTEREST
The authors declare no conflict of interest.
ACKNOWLEDGEMENTS
Financial support by the European Union within European Regional
Development Fund, Project POIG.01.01.02.-14-102/09 is gratefully
acknowledged. MP thanks the National Science Centre for PRELUDIUM grant
(2014/13/N/ST5/01758).
13C NMR (150 MHz, CDCl3) δ 177.1, 159.1, 138.0, 130.4, 129.3, 128.4,
127.7, 127.4, 113.7, 84.2, 72.9, 72.3, 67.7, 66.3, 64.4, 61.3, 55.2, 54.0, 36.3, 25.7,
22.7, 18.0, − 4.2, −4.9.
HRMS calcd for C30H43NO5NaSi [M+H]+ 548.2808, found 548.2818.
(2S,3S,5R,6S,1′R)-3-Benzyloxy-6-(1′-tert-butyldimethylsilyl-
oxyethyl)-2-hydroxymethyl-1-azabicyclo[3.2.0]heptan-7-one (5)
Compound 23 (0.2 g, 0.37 mmol) was dissolved in dichloromethane (3.7 ml)
and water (0.015 ml) was added. Subsequently, the solution was cooled to
0 °C and treated with DDQ (2 eq. 0.17 g, 0.74 mmol). The reaction mixture
was stirred for about 30 min, After TLC showed the disappearance of the
substrate, the reaction mixture was extracted with AcOEt, and the extracts were
evaporated and purified on silica gel using hexane/AcOEt 6:4v/v as the eluent to
afford 5, 0.11 g (77%).
1
2
3
4
5
Tufariello, J. J., Lee, G. E., Senaratne, P. A. & Al–Nuri, M. Thienamycin. A solution of
the stereochemical problem. Tetrahedron Lett. 20, 4359–4362 (1979).
Coulton, S.
& Luscombe D. K.) 99–145 (Elsevier, Cambridge, UK, 1996).
Hashizume, T. Morishima, H. Design and synthesis of new 1-beta-
methylcarbapenems. Drugs Future 25, 833–841 (2000).
Morin, R. B. Gorman, M. Chemistry and Biology of β-Lactam Antibiotics
& Hunt, E. in Progress in Medicinal Chemistry (eds Ellis G. P.
&
&
118–121 (Academic Press, New York, USA, 1982).
Palomo, C. in Recent Progress in the Chemical Synthesis of Antibiotics
565–612 (Springer–Verlag, Berlin Heidelberg, 1990).
The Journal of Antibiotics

Synthesis of Thienamycin
M Pieczykolan et al
7
6
Bouffard, F. A., Johnston, D. B. R. & Christensen, B. G. Thienamycin total synthesis. 1.
Synthesis of azetidinone precursors of ( )–thienamycin and its stereoisomers. J. Org.
Chem. 45, 1130–1135 (1980).
17 Śnieżek, M. et al. Thermal and Sc(OTf)3 catalyzed 1,3–dipolar cycloaddition of open–
chain nitrones to α,β–unsaturated lactones: combined experimental and computational
studies. Tetrahedron Asymmetry 24, 89–103 (2013).
7
8
Johnston, D. B. R., Schmitt, S. M., Bouffard, F. A. & Christensen, B. G. Total synthesis
of ( )–thienamycin. J. Am. Chem. Soc. 100, 313–315 (1978).
Kametani, T., Huang, S.-P., Yokohama, S., Suzuki, Y. & Ihara, M. Studies on the
syntheses of heterocyclic compounds. 800. A formal total synthesis of ( )–thienamycin
18 Kinugasa, M. & Hashimoto, S. The reactions of copper(I) phenylacetylide with nitrones.
J. Chem. Soc. Chem. Commun. 8, 466–467 (1972).
19 Stecko, S., Furman, B. & Chmielewski, M. Kinugasa reaction: an ‘ugly duckling’ of
β–lactam chemistry. Tetrahedron 70, 7817–7844 (2014).
and
a
(
)–decysteaminylthienamycin derivative. J. Am. Chem. Soc. 102,
20 Maciejko, M. et al. An entry to the carbapenem antibiotic scaffold via the asymmetric
2060–2065 (1980).
kinugasa reaction. Synthesis 44, 2825–2839 (2012).
9
Schmitt, S. M., Johnston, D. B. R. & Christensen, B. G. Thienamycin total synthesis. 2.
Model studies–synthesis of a simple 2–(alkylthio)carbapen–2–em. J. Org. Chem. 45,
1135–1142 (1980).
21 Soluch, M., Grzeszczyk, B., Chmielewski, M. & Furman, B. Synthesis of Thienamycin
methyl ester from 2–deoxy–d–ribose via Kinugasa reaction. J. Antibiot. 69,
164–168 (2016).
10 Schmitt, S. M., Johnston, D. B. R. & Christensen, B. G. Thienamycin total synthesis. 3.
Total synthesis of ( )–thienamycin and ( )–8–epithienamycin. J. Org. Chem. 45,
1142–1148 (1980).
22 Pieczykolan, M., Furman, B. & Chmielewski, M. 1,3–Dipolar cycloaddition of a cyclic
nitrone derived from 2–deoxy–D–ribose to α,β–unsaturated lactones: An entry to
carbapenem antibiotics. Carbohydr. Res. 433, 89–96 (2016).
11 Salzmann, T. N., Ratcliffe, R. W., Christensen, B. G. & Bouffard, F. A. A stereocon-
trolled synthesis of (+)–thienamycin. J. Am. Chem. Soc. 102, 6161–6163 (1980).
23 Stecko, S. et al. Synthesis of iminosugars via 1,3–dipolar cycloaddition reactions of
nitrones to α,β–unsaturated sugar aldonolactones. C. R. Chim. 14, 102–125 (2011).
12 Shibasaki, M., Nishida, A.
of proipiolic esters to β–keto esters. Application to the formal total synthesis of
)–thienamycin. Tetrahedron Lett. 23, 2875–2878 (1982).
&
Ikegami, S. A.
A
mild method for the conversion
24 Ohta, T. et al. Synthesis of (6S,8R)–6–(1'–Hydroxyethyl)carbopenem,
Thienamycin Type. Heterocycles 33, 143–146 (1992).
a
(
25 Liu, C., Kang, H., Wightman, R. H. & Jiang, S. Stereoselective synthesis of a novel
Galf–disaccharide mimic: β–d–galactofuranosyl–(1–5)–β–d–galactofuranosyl motif of
mycobacterial cell walls. Tetrahedron Lett. 54, 1192–1194 (2013).
26 Hanessian, S., Desilets, D. & Bennani, L. Y. A novel ring-closure strategy for the
carbapenems: the total synthesis of (+)–thienamycin. J. Org. Chem. 55,
3098–3103 (1990).
27 Karady, S., Amato, J. S., Reamer, R. A. & Weinstock, L. M. Stereospecific conversion of
penicillin to thienamycin. J. Am. Chem. Soc. 103, 6765–6767 (1981).
28 Melillo, D. G., Cvetovich, R. J., Ryan, K. M. & Sletzinger, M. An enantioselective
approach to (+)-thienamycin from dimethyl 1,3-acetonedicarboxylate and (+)-α-methyl-
benzylamine. J. Org. Chem. 51, 1498–1504 (1986).
13 Shibasaki, M., Nishida, A. & Ikegami, S. A simple preparation of (+)–4–phenylthioa-
zetidin–2–one and an asymmetric synthesis of (+)–thienamycin. J. Chem. Soc. Chem.
Commun. 22, 1324–1325 (1982).
14 Tatsuta, K., Takahashi, M., Tanaka, N.
& Chikauchi, K. Novel synthesis of
(+)–4–acetoxy–3–hydroxyethyl–2–azetidinone from carbohydrate. A formal total synth-
esis of (+)–thienamycin. J. Antibiot. 53, 1231–1234 (2000).
15 Panfil, I., Bełżecki, C., Urbańczyk-Lipkowska, Z.
cycloaddition of nitrones to sugar enlactones.
10087–10094 (1991).
16 Śnieżek, M., Stecko, S., Panfil, I., Furman, B. & Chmielewski, M. Total synthesis
&
Chmielewski, M. 1,3–dipolar
Tetrahedron 47,
of ezetimibe,
(2013).
a
cholesterol absorption inhibitor. J. Org. Chem. 78, 7048–7057
29 Frankie Mak, S. Y. et al. Synthesis of (+)–Obtusenyne. Chem. Eur. J. 14,
2867–2885 (2008).
Supplementary Information accompanies the paper on The Journal of Antibiotics website (http://www.nature.com/ja)
The Journal of Antibiotics