quantitative yield). The crude
synthesis of 10 and 11
9 was used directly in the
4
.5. Cbz-vsLeu-ONBu
4
(7)
4
(6.1 g, 17 mmol) and NBu I (6.3
.
A solution of compound
6
g, 17 mmol) in acetone (400 mL) was stirred overnight
4.8. Cbz-Leu
3
-VSF (10)
under reflux. The reaction mixture was then concentrated in
To HCl salt
added BOP (86.7 mg, 0.196 mmol), Cbz-Leu
mg, 0.187 mmol), CH Cl
9
(43.3 mg, 0.187 mmol) were subsequently
-OH[9] (70.8
(5 mL), and DiPEA (69 µL, 0.393
mmol). The mixture was stirred overnight at rt under N
vacuo and coevaporated with CHCl
3
(3x50 mL), yielding
2
compound as a dense yellow oil (11.3 g). TLC analysis
7
2
2
showed that the crude product was pure enough for being
2
.
1
used in the next step without further purification. H NMR
During the reaction, the pH was monitored (pH indicator
paper) and kept to approximately 9 by adding additional
DiPEA, if necessary. After evaporation of the solvent, the
residue was dissolved in EtOAc (15 mL) and was washed
(
7
CH
CH
400 MHz, CDCl
.3 Hz, 12H, 4
3
): δ 0.88 (m, 6H, CH(CH
3
)
2
), 1.00 (t, J =
)), 1.42 (m, 10H,
)), 1.65 (m, 9H, 4 x
), 3.30 (m, 8H, 4 x NCH
x
CH
CH
3
(NBu
(NBu
4
2
CH(CH
CH CH
3
3
)
2
, 4 x CH
(NBu
2
3
4
2
2
4
), CH(CH
3
)
2
2
with KHSO
organic layer was dried over Na
Purification with silica gel column chromatography (eluent:
4
(1.0 M, 3×10 mL), and brine (10 mL). The
(
5
NBu
4
)), 4.37 (m, 1H, NCH), 4.61 (d, J = 9.1 Hz, 1H, NH),
.05 (q, J = 12.3 Hz, 2H, CH (Cbz)), 6.40 (dd, J = 15.3, 4.6
), 6.48 (dd, J = 15.3, 1.1 Hz, 1H,
2
SO and concentrated.
4
2
1
2
3
Hz, 1H, CH=CHSO
CH=CHSO ), 7.34 (m, 5H, C
MHz, CDCl ): δ 13.7 (CH (NBu
2.2, 22.8 (CH(CH ), 24.1 (CH
CH(CH ), 44.4 (CH CH(CH ), 49.4 (NCH), 58.9 (NCH
NBu )), 66.5 (CH (Cbz)), 127.9, 128.4, 136.6 (C
Cbz)), 133.9 (CH=CHSO ), 134.6 (CH=CHSO
C=O). HRMS m/z calculated for C15 S [M-NBu
3
26% EtOAc in hexanes) afforded Cbz-Leu -Leu -Leu -VSF
1
3
1
3
6
H
5
(Cbz)). C NMR (126
)), 19.7 (CH CH (NBu )),
CH CH (NBu )), 24.6
(
10) as a white solid (26.8 mg, 0.048 mmol, 26% yield). H
NMR (300 MHz, CDCl ): δ = 0.85-1.01 [m, 18H, 3 x
CH(CH ], 1.41-1.86 [m, 9H, 3 x CH CH(CH ], 4.14 [m,
1H, NCH (Leu )], 4.38 [m, 1H, NCH (Leu )], 4.74 [m, 1H,
3
3
4
2
3
4
3
2
3
)
2
2
2
3
4
3
)
2
2
3 2
)
1
2
(
(
(
(
3
)
2
2
3
)
2
2
3
4
2
6
H
5
2
NCH (Leu )], 5.11 [2d, J = 12.2 Hz, 2H, CH (Cbz)], 5.38
1
2
3
3
), 155.6
[d, J = 5.0 Hz, 1H, NH (Leu )], 6.60 [m, 2H, 2 x NH, (Leu ),
CH=CHS], 7.00 [d, J = 8.1 Hz, NH (Leu )], 7.05 (dd, JAX
-
3
H
20NO
5
4
] :
=
3
26.1068, found: 326.1055.
4.5 Hz, JAB = 15.2 Hz, 1H, CH=CHS), 7.30-7.43 (m, 5H,
1
3
C
6
H
5
); C NMR (75 MHz, CDCl
22.8, 24.8, 25.0 (CH CH(CH
(CH CH(CH ), 48.0 (NCH ), 52.3 (NCH ), 54.3 (NCH ),
67.3 [CH (Cbz)], 121.7, 122.1 (d, J = 27.4 Hz, CH=CHS),
127.9, 128.4, 128.6, 135.7 (C ), 153.3 (CH=CHS), 156.7
[C=O (Cbz)], 171.5, 172.7 [C=O (Leu )]; F NMR (376
MHz, CDCl ): δ = 59.2 (s); HRMS m/z calculated for
3
): δ = 21.6, 21.7, 21.8,
4.6. Cbz-Leu-VSF (8)
2
3 2
)
), 39.9, 40.8, 42.1
3
2
1
To a solution of compound
CH Cl (170 mL) was added XtalFluor-M® (3.72 g, 15.3
mmol), under N atmosphere. A catalytic quantity of
Et N∙3HF (59 µL, 360 µmol) was added to the mixture,
which was stirred overnight under reflux. After destruction
of residual XtalFluor-M® by addition of silica gel to the
solution, the mixture was filtered and concentrated in vacuo.
7
(4.8 g, 7.2 mmol) in dry
2
3 2
)
2
2
2
2
6 5
H
1
,2
19
3
3
+
27 3 6
C H43FN O S [M + H] : 556.2858, measured: 556.2857.
Purification by silica gel chromatography (eluent: CH
petroleum ether (2/1)), afforded peptido vinylsulfonyl
fluoride as a white solid (720 mg, 2.18 mmol, 30% yield).
Mp = 120°C. H NMR (300 MHz, CDCl
.6 Hz, 6H, CH(CH ), 1.47 [t, J = 7.4 Hz, 2H,
CH CH(CH ], 1.71 (m, 1H, CH(CH ), 4.53 (m, 1H,
NCH), 4.72 (br d, 1H, NH), 5.13 [s, 2H, CH (Cbz)], 6.52
d, J = 15.3 Hz, 1H, CH=CHS), 7.06 (dd, JAX = 4.8 Hz, JAB
2
Cl
2
/
4.9. Cbz-Leu
4
-VSF (11)
Cbz-Leu -OMe (550 mg, 1.0 mmol)[23] was dissolved in
3
8
Tesser’s base (12.5 mL, mixture of NaOH (2.0 M), MeOH
and dioxane, in proportion 1:5:14 (v/v/v)). After the mixture
was stirred overnight at rt, it was neutralized to pH 7 (pH
1
3
): δ = 0.96 (d, J =
6
3 2
)
2
3
)
2
3
)
2
indicator paper) with KHSO
evaporated in vacuo and the mixture was acidified to pH 2
(pH indicator paper) with KHSO (1.0 M). The water layer
was extracted with EtOAc (2x30 mL). The organic layer
was washed with H O (50 mL) and with brine (40 mL),
dried over anhydrous Na SO and concentrated in vacuo,
yielding Cbz-leu -OH as a white solid (501 mg, 1.0 mmol,
quantitative yield). Cbz-Leu -OH was coupled to HCl·H-
Leu-VSF ( ) using the procedure described in the synthesis
4
(1.0 M). The dioxane was
2
(
4
1
3
=
15.3 Hz, 1H, CH=CHS), 7.37 (s, 5H, C
): δ = 21.6, 22.6 (CH(CH ), 24.6 [CH(CH
CH(CH ), 50.1 (NCH), 67.3 [CH (Cbz)], 121.7
d, J = 27.8 Hz, CH=CHS), 128.1, 128.3, 128.6 (C ),
35.8 (Ar-C), 153.6 (CH=CHS), 155.5 (C=O); F NMR
): δ = 60.4 (s). HRMS m/z calculated for
6
H
5
). C NMR (75
MHz, CDCl
2.5 (CH
3
3
)
2
3
)
2
],
2
4
(
1
2
3
)
2
2
2
4
5
H
6
3
1
9
3
(471 MHz, CDCl
3
9
-
C
15
H
19FNO
4
S [M-H] : 328.1024, found: 328.1017.
of 10. The scale of this reaction was 0.23 mmol. Purification
with silica gel column chromatography (eluent: 36% EtOAc
1
2
3
4
4
.7. HCl·H-Leu-VSF (9)
A stirred solution of compound
CH Cl (2.3 mL) was put under N
in hexanes) afforded Cbz-Leu -Leu -Leu -vsLeu -F (11) as a
1
8
(75.8 mg, 0.23 mmol) in
atmosphere. After
white solid (51.8 mg, 0.077 mmol, 33% yield). H NMR
2
2
2
(300 MHz, CDCl
3
): δ = 0.77-1.03 (m, 24H, 4 x CH(CH
CH(CH ), 3.93 [m, 1H, NCH
(Leu )], 4.19, 4.38 [2 x m, 2H, 2 x NCH (Leu )], 4.75 [m,
1H, NCH (Leu )], 5.14 [s, 2H, CH
(Leu )], 6.40, 7.06 [2d, J = 4.6 Hz, J = 7.3 Hz, 2H, NH
(Leu )], 6.68 (dt, JAB = 15.0 Hz, JAX = 2.0 Hz, JAF = 2.0 Hz,
CH=CHS], 7.08 [m, 2H, CH=CHS, NH (Leu )], 7.29-7.43
); C NMR (75 MHz, DMSO-d
21.5, 21.6, 21.7, 22.9, 23.0, 24.2 (CH
3 2
) ),
addition of HBr in acetic acid (33% v/v, 1.4 mL) stirring
was continued for 30 min at rt. Then the solvents were
evaporated and the residue dissolved in H
Dowex-Cl (2×8, 200 mg) was added and the solution was
stirred for 5 min at rt. and then filtrated. The water layer was
washed with EtOAc (2x3.5 mL), then concentrated in vacuo
and coevaporated with toluene (3x5 mL), yielding HCl∙H-
1.38-1.90 (m, 12H, 4 x CH
2
3 2
)
1
2,3
4
2
O (3.5 mL).
2
(Cbz], 5.20 [s, 1H, NH
1
2
,3
4
1
3
(m, 5H, C
6
H
5
6
): δ = 21.2,
), 40.2,
Leu-VSF (
9) as a yellowish solid (53.7 mg, 0.23 mmol,
2
CH(CH )
3 2