2644 J . Org. Chem., Vol. 61, No. 8, 1996
Eberling et al.
7.9 Hz, 1H, 2-H), 5.01, (dd, J 3,2 ) 10.4 Hz, J 3,4 ) 3.4 Hz, 1H,
3-H), 4.46 (d, J 1,2 ) 7.8 Hz, 1H, 1-H), 4.36-4.23 (m, 3H, R-CH
Ser, COOCH2 MEE), 4.18-4.05 (m, 3H, 6-Ha, 6-Hb, â-CH2a
Ser), 4.00-3.81 (m, 2H, â-CH2b Ser, 5-H); 100.6 MHz 13C-NMR
(CDCl3) δ ) 101.66 (C-1), 70.82, 70.71, 68.62, 66.93 (C-2, C-3,
C-4, C-5), 69.45 (â-CH2 Ser), 61.10 (C-6), 54.35 (R-CH Ser).
) 8.4 Hz, 1H, 2-H), 4.03 (m, 2H, 6-Ha, 5-H), 4.01 (dd, J 5,6b
6.6 Hz, J 6a,6b ) 10.6 Hz, 1H, 6-Hb), 3.78 (dd, J 1 ) 3.9 Hz, J 2
)
)
10.6 Hz, 1H, â-CH2a Ser), 3.78 (dd, J 1 ) 5.1, J 2 ) 10.6 Hz, 1H,
â-CH2b Ser); 100.6-MHz 13C-NMR (CDCl3) δ ) 97.97 (C-1),
68.83, 64.42 (OCH2 Aloc, â-CH2 Ser), 67.75, 67.14, 66.22 (C-3,
C-4, C-5) 61.54 (C-6), 55.07 (R-CH Ser), 47.04 (C-2); C21H30N2O13.
N-(9-F lu or en ylm et h yloxyca r b on yl)-O-(2-a cet a m id o-
3,4,6-t r i-O -a c e t y l-2-d e o x y -r-D -g a la c t o p y r a n o s y l)-L -
ser in e (12b): yield 1.18 g (90%); colorless amorphous solid;
[R]22 ) +90.7 (c ) 1.0, CHCl3) (lit.19 [R]22 ) +89.9 (c ) 1.0,
Anal. Calcd for C26H39NO16
: C, 50.24; H, 6.32; N, 2.25.
Found: C 49.72, H 5.94, N 1.89.
N-(Allyloxyca r bon yl)-O-(2,3,4,6-tetr a -O-a cetyl-â-D-ga -
la ctop yr a n osyl)-L-th r eon in e (m eth oxyeth oxy)eth yl ester
D
D
(11d ): yield 439 mg (69%); colorless oil; [R]22 ) -66.4 (c )
CHCl3)); Rf ) 0.38 (ethyl acetate/methanol ) 2:1); C32H36N2O13.
N -(Be n zyloxyca r b on yl)-O-(2-a ce t a m id o-3,4,6-t r i-O-
a c e t y l-2-d e o x y -r-D -g a la c t o p y r a n o s y l)-L -t h r e o n i n e
(12c): yield 839 mg (72%); colorless crystals; mp 94-98 °C;
D
1.0, CHCl3); Rf ) 0.42 (petroleum ether/ethyl acetate ) 1:4);
1
400 MHz H-NMR (CDCl3) δ ) 5.55 (d, J ) 9.1 Hz, 1H, NH),
5.32 (d, J 4,5 ) 3.3 Hz, 1H, 4-H), 5.05 (dd, J 2,3 ) 10.4 Hz, J 2,1
)
[R]22 ) +94.2 (c ) 0.55, CH3OH); Rf ) 0.33 (ethyl acetate/
7.8 Hz, 1H, 2-H), 4.95 (dd, J 3,4 ) 3.3 Hz, J 3,2 ) 10.5 Hz, 1H,
3-H), 4.44 (d, J 1,2 ) 7.8 Hz, 1H, 1-H), 4.39-4.15 (m, 4H, â-CH
Thr, R-CH Thr, H-6a, H-6b), 3.85 (m, 1H, 5-H), 1.21 (d, J )
8.8 Hz, 3H, γ-CH3 Thr); 100.6 MHz 13C-NMR (CDCl3) δ )
100.05 (C-1), 75.85 (â-CH Thr), 70.71, 70.54, 68.91, 66.84 (C-
2, C-3, C-4, C-5), 60.85 (C-6), 58.94 (R-CH Thr), 17.63 (γ-CH3
Thr). Anal. Calcd for C27H41NO16: C, 51.02; H, 6.50; N, 2.21.
Found: C, 50.84; H, 6.50; N, 2.22.
D
methanol ) 2:1); 400-MHz 1H-NMR (CD3OD) δ ) 5.42 (d, 1H,
4-H), 5.13 (dd, J 2,3 ) 11.6 Hz, J 3,4 ) 3.1 Hz, 1H, 3-H), 5.00 (d,
J 1,2 ) 3.8 Hz, 1H, 1-H), 4.47 (dd, J 1 ) 1.7 Hz, J 2 ) 6.5 Hz, 1H,
â-CH Thr), 4.42 (dd, J 1,2 ) 3.8 Hz, J 2,3 ) 11.5 Hz, 1H, 2-H),
4.36 (t, J 5,6 ) 6.5 Hz, 1H, 5-H), 4.32 (d, J ) 1.2 Hz, 1H, R-CH
Thr), 4.14-4.13 (m, 2H, 6-Ha/b), 1.35 (d, J ) 6.5 Hz, 3H, CH3
Thr); 100.6-MHz 13C-NMR (CD3OD) δ ) 100.59 (C-1), 77.79
(â-CH Thr), 69.82, 68.86, 68.17 (C-3, C-4, C-5), 63.32 (C-6),
60.36 (R-CH Thr), 48.79 (C-2), 19.14 (γ-CH3 Thr). Anal. Calcd
for C26H34N2O13‚H2O: C, 52.00; H, 6.04; N, 4.66. Found: C,
52.26; H, 5.78; N, 4.57.
N-(Allyloxyca r bon yl)-O-(2,3,4-tr i-O-a cetyl-â-D-xylop y-
r a n osyl)-L-ser in e (m eth oxyeth oxy)eth yl ester (11e): yield
423 mg (77%); colorless oil; [R]22D ) -45.1 (c ) 1.0, CHCl3); Rf
) 0.46 (petroleum ether/ethyl acetate ) 1:4); 400 MHz 1H-
N-(Allyloxyca r bon yl)-O-(2,3,4,6-tetr a -O-a cetyl-â-D-glu -
NMR (CDCl3) δ ) 5.53 (d, J ) 8.3 Hz, 1H, NH), 5.08, (t, J 3,4
7.96 Hz, J 3,2 ) 7.9 Hz, 1H, 3-H), 4.85 (dd, J 2,3 ) 7.9 Hz, J 2,1
)
)
cop yr a n osyl)-L-ser in e (13a ): yield 997 mg (96%); colorless
oil; [R]22 ) +57.2 (c ) 1.0, CH3OH); Rf ) 0.25 (ethyl acetate/
4.8 Hz, 1H, 4-H), 4.81 (dd, J 2,3 ) 8.0 Hz, J 2,1 ) 6.1 Hz, 1H,
2-H), 4.47 (d, J 1,2 ) 6.1 Hz, 1H, 1-H), 4.34-4.25 (m, 3H, R-CH
Ser, COOCH2 MEE), 4.21 (dd, J 1 ) 10.8 Hz, J 2 ) 3.2 Hz, 1H,
â-CH2a Ser), 4.02 (dd, J 5a,5b ) 12.9 Hz, J 5a,4 ) 4.7 Hz, 1H, 5-Ha),
3.77 (m, J 1 ) 2.9 Hz, J 2 ) 10.3 Hz, 1H, â-CH2b Ser), 3.33 (m,
J 5b,5a ) 12.0 Hz, J 5b,4 ) 8.0 Hz, 1H, 5-Hb); 100.6 MHz 13C-
NMR (CDCl3) δ ) 100.59 (C-1), 70.67, 70.20, 68.48 (C-2, C-3,
C-4), 69.10 (â-CH2 Ser), 61.57 (C-5), 54.19 (R-CH Ser). Anal.
Calcd for C23H35NO14: C, 50.27; H, 6.24; N, 2.55. Found: C,
49.68; H, 6.00; N, 2.23.
D
ethanol ) 2:1); 400 MHz 1H-NMR (CDCl3) δ ) 5.64 (d, J )
8.0 Hz, 1H, NH), 5.15 (t, J 3,4 ) 9.3 Hz, J 3,2 ) 9.4 Hz, 1H, 3-H),
5.04 (t, J 4,5 ) 9.7 Hz, J 4,3 ) 9.5 Hz, 1H, 4-H), 4.93 (dd, J 2,3
)
9.2 Hz, J 2,1 ) 8.0 Hz, 1H, 2-H), 4.51 (d, J 1,2 ) 7.9 Hz, 1H, 1-H),
4.46 (m, J ) 4.0 Hz, 1H, R-CH Ser), 4.24 (dd, J 6a/6b ) 10.7 Hz,
J 6a/5 ) 2.8 Hz, 1H, 6-Ha), 4.18 (dd, J 1 ) 4.4 Hz, J 2 ) 12.4 Hz,
1H, â-CH2a Ser), 4.12 (dd, J 6b,6a ) 12.3 Hz, J 6b,5 ) 2.4 Hz, 1H,
6-Hb), 4.07 (dd, J 1 ) 3.4 Hz, J 2 ) 10.6 Hz, 1H, â-CH2b Ser),
3.67 (m, 1H, 5-H); 100.6 MHz 13C-NMR (CDCl3) δ ) 100.97
(C-1), 72.62, 71.86, 71.08, 68.30 (C-2, C-3, C-4, C-5), 69.42 (â-
CH2 Ser), 61.82 (C-6), 53.99 (R-CH Ser). Anal. Calcd for
C21H29NO14: C, 48.54; H, 5.63; N, 2.70. Found: C, 48.57; H,
5.67; N, 2.73.
N-(Allyloxyca r bon yl)-O-(2,3,4-tr i-O-a cetyl-â-D-xylop y-
r a n osyl)-L-th r eon in e (m eth oxyeth oxy)eth yl ester (11f):
yield 411 mg (73%); colorless oil; [R]22 ) -361.2 (c ) 1.0,
D
CHCl3); Rf ) 0.41 (petroleum ether/ethyl acetate ) 1:4); 400
MHz 1H-NMR (CDCl3) δ ) 5.40 (d, J ) 7.7 Hz, 1H, NH), 5.08,
4.84, (t, m, 2H, 3-H, 4-H), 4.78 (dd, J 2,3 ) 8.3 Hz, J 2,1 ) 6.6
Hz, 1H, 2-H), 4.47 (d, J 1,2 ) 8.0 Hz, 1H, 1-H), 4.39 (m, 1H,
â-CH Thr), 4.33 (m, 1H, R-CH Thr), 3.97 (dd, J 5a,5b ) 11.8 Hz,
J 5a,4 ) 4.9 Hz, 1H, 5-Ha), 3.28 (dd, J 5b,5a ) 11.8 Hz, J 5b,4 ) 8.4
Hz, 1H, 5-Hb), 1.18 (d, J ) 6.3 Hz, 3H, γ-CH3 Thr); 100.6 MHz
13C-NMR (CDCl3) δ ) 98.79 (C-1), 74.69 (â-CH Thr), 70.97,
70.61, 68.61 (C-2, C-3, C-4), 61.67 (C-5), 58.41 (R-CH Thr),
17.09 (γ-CH3 Thr). Anal. Calcd for C24H37NO14: C, 51.15; H,
6.62; N, 2.49. Found: C, 50.76; H, 6.20; N, 2.61.
N-(Allyloxyca r bon yl)-O-(2,3,4,6-tetr a -O-a cetyl-â-D-glu -
cop yr a n osyl)-L-th r eon in e (13b). Difficult separation of
product and byproduct by flash chromatography: yield 320
mg (30%); colorless oil; [R]22 ) -83.7 (c ) 1.0, CH3OH); Rf )
D
1
0.25 (ethyl acetate/ethanol ) 2:1); 400 MHz H-NMR (CDCl3)
δ ) 5.51 (d, J ) 9.1 Hz, 1H, NH), 5.14 (t, J 3,4 ) 9.4 Hz, J 3,2
)
9.4 Hz, 1H, 3-H), 5.05, (t, J 4,3 ) 9.7 Hz, J 4,5 ) 9.5 Hz, 1H,
4-H), 4.88 (dd, J 2,3 ) 9.2 Hz, J 2,1 ) 7.9 Hz, 1H, 2-H), 4.50 (d,
J 1,2 ) 7.9 Hz, 1H, 1-H), 4.37 (dd, J 6a,6b ) 11.9 Hz, J 6a,5 ) 2.5
Hz, 1H, 6-Ha), 4.34-4.24 (m, 2H, â-CH Thr, R-CH Thr), 4.04
(dd, J 6b,6a ) 12.3 Hz, J 6b,5 ) 3.8 Hz, 1H, 6-Hb), 3.64 (m, J 5,6a
)
Gen er a l P r oced u r e for th e Hyd r olysis of O-Glycosyl
Am in o Acid (Meth oxyeth oxy)eth yl Ester s w ith P a p a in
12/13. The glycosylated amino acid MEE ester 7a -c/11a -f
(2mmol) was dissolved in 1.5 mL of acetone and added to a
solution of 300 mg of papain in cystein buffer (36 mL). The
solution was shaken for 3 d at 37 °C, saturated with NaCl,
and extracted five times with ethyl acetate (25 mL). The
organic layer was dried with MgSO4 and evaporated and the
remaining product purified by flash chromatography (ethyl
acetate/petroleum ether ) 4:1 f ethyl acetate f ethyl acetate/
ethanol ) 1:4).
N-(Allyloxycar bon yl)-O-(2-acetam ido-3,4,6-tr i-O-acetyl-
2-d eoxy-r-D-ga la ctop yr a n osyl)-L-ser in e (12a ): yield 778
mg (75%); colorless amorphous solid; [R]22D ) +113.3 (c ) 1.0,
CHCl3) (lit.18 [R]22D ) +117.5 (c ) 1.0, CHCl3)); Rf ) 0.13 (ethyl
acetate/methanol ) 2:1); 400-MHz 1H-NMR (DMSO-d6) δ )
7.87 (d, J ) 8.4 Hz, 1H, NH), 7.14 (d, J ) 7.8 Hz, 1H, NH
Ser), 5.27 (d, 1H, 4-H), 5.00 (dd, J 2,3 ) 11.7 Hz, J 3,4 ) 3.1 Hz,
1H, 3-H), 4.82 (d, J 1,2 ) 3.4 Hz, 1H, 1-H), 4.24 (t, J ) 6.3 Hz,
1H, R-CH Ser), 4.17 (ddd, J 1,2 ) 3.4 Hz, J 2,3 ) 11.6 Hz, J 2-H,NH
2.9 Hz, J 5,6b ) 3.2 Hz, J 5,4 ) 9.8 Hz, 1H, 5-H), 1.19 (d, J ) 6.3
Hz, 3H, γ-CH3 Thr); 100.6 MHz 13C-NMR (CDCl3) δ ) 99.79
(C-1), 76.29 (â-CH Thr), 72.56, 71.62, 71.06, 68.26 (C-2, C-3,
C-4, C-5), 61.34 (C-6), 58.07 (R-CH Thr), 17.71 (γ-CH3 Thr).
Anal. Calcd for C22H31NO14
: C, 49.53; H, 5.86; N, 2.63.
Found: C, 49.10; H, 6.25; N, 2.94.
N-(Allyloxyca r bon yl)-O-(2,3,4,6-tetr a -O-a cetyl-â-D-ga -
la ctop yr a n osyl)-L-ser in e (13c): yield 852 mg (82%); color-
less oil; [R]22 ) +152.8 (c ) 1.0, CH3OH); Rf ) 0.33 (ethyl
D
acetate/ethanol ) 2:1); 400 MHz 1H-NMR (CDCl3) δ ) 5.61
(d, J ) 7.7 Hz, 1H, NH), 5.34 (d, J 4,5 ) 3.2 Hz, 1H, 4-H), 5.12
(dd, J 2,3 ) 10.3 Hz, J 2,1 ) 7.9 Hz, 1H, 2-H), 4.97, (dd, J 3,2
)
10.4 Hz, J 3,4 ) 3.36 Hz, 1H, 3-H), 4.47 (d, J 1,2 ) 7.8 Hz, 1H,
1-H), 4.56-4.46 (m, 1H, R-CH Ser), 4.36 (m, 1H, â-CH2a Ser),
4.13 (dd, J 6a,6b ) 11.2 Hz, J 6a,5 ) 6.4 Hz, 1H, 6-Ha), 4.06 (dd,
J 6b,6a ) 11.1 Hz, J 6a,5 ) 6.8 Hz, 1H, 6-Hb), 4.03-3.86 (m, 2H,
â-CH2b Ser, 5-H); 100.6 MHz 13C-NMR (CDCl3) δ ) 101.58 (C-
1), 70.84, 70.69, 68.64, 66.95 (C-2, C-3, C-4, C-5), 69.34 (â-
CH2 Ser), 61.16 (C-6), 54.87 (R-CH Ser). Anal. Calcd for
C21H29NO14: C, 48.54; H, 5.63; N, 2.70. Found: C, 48.45; H,
5.83; N, 2.70.
(18) (a) Paulsen, H.; Merz, G.; Brockhausen, I. Liebigs Ann. Chem.
1990, 719. (b) Paulsen, H.; Merz, G.; Brockhausen, I. Liebigs Ann.
Chem. 1990, 1272.
(19) Paulsen, H.; Adermann, K. Liebigs Ann. Chem. 1989, 751.