322
ORGANIC SYNTHESIS—1995
V.C. Carboxvl Protecting Groups
V.C-1 Kita, Y. et al., CPB, 42, 147; Ogawa, T. et al., CPB, 42, 1579.
HO(CH 2 ) 2 CN
/
D C C
'
D M A P
\
R ^ o ^ ^
R-C0 2 H .
Ύ
^ ^
C N
64-100%
\
1:TBAF
/
O 8 6 . 9 7 %
2:H
+
V.C-2 Ravi, D., Rao, V.J., et al., SL, 856; Nagasawa, K. et al., CL, 209.
O
1: Dìphosgene, pyr, DCM
II
R - C 0 2 H
-40°C
^ R ^ ^ X "
R '
2: R—XH (X = 0,S)
4 9 . 9 4 %
V.C-3 Naito, T. et al., SL, 637.
Me
BnSAIMe 3 Li
R
Ï
O H
Ph-Me,0°C
γ ^ > p
V.C-4 Anson, M.S. and Montana, J.G., SL, 219.
l:NBS,(PhCO>20
R
-
C
°
2 B n
CCi^A
**
R
-
C O
*
H
2: H 2 0
0-97 %
ORGANIC SYNTHESIS—1995
V.C. Carboxvl Protecting Groups
V.C-1 Kita, Y. et al., CPB, 42, 147; Ogawa, T. et al., CPB, 42, 1579.
HO(CH 2 ) 2 CN
/
D C C
'
D M A P
\
R ^ o ^ ^
R-C0 2 H .
Ύ
^ ^
C N
64-100%
\
1:TBAF
/
O 8 6 . 9 7 %
2:H
+
V.C-2 Ravi, D., Rao, V.J., et al., SL, 856; Nagasawa, K. et al., CL, 209.
O
1: Dìphosgene, pyr, DCM
II
R - C 0 2 H
-40°C
^ R ^ ^ X "
R '
2: R—XH (X = 0,S)
4 9 . 9 4 %
V.C-3 Naito, T. et al., SL, 637.
Me
BnSAIMe 3 Li
R
Ï
O H
Ph-Me,0°C
γ ^ > p
V.C-4 Anson, M.S. and Montana, J.G., SL, 219.
l:NBS,(PhCO>20
R
-
C
°
2 B n
CCi^A
**
R
-
C O
*
H
2: H 2 0
0-97 %