Chemistry Reference
In-Depth Information
O
O
O
I
I
I
HN
HN
HN
O
N
N
O
Br
O
N
DMTrO
DMTrCl
Pyr, DMAP
HO
HO
O
O
1.
O
NaOH, PhH
2. 3% TFA, CHCl
3
OH
OH
O
O
CuI/Pd(0),
DMF
H
CF
3
O
O
O
NH
2
N
H
CF
3
HN
HN
O
O
O
O
N
O
N
O
P
O
P
O
P
O
HO
O
O
O
OH
OH
1. POCl
3
/(MeO)
3
P(O)
2. (Bu
3
NH)
4
P
2
O
7
3. 0.1M TEAB/NH
4
OH
O
O
O
O
Na
2
CO
3
/ NaHCO
3
,
pH=8.7
N
O
O
N
N
N
B
F
F
O
2
N
O
O
O
O
H
O
N
N
N
HN
B
F
F
O
2
N
O
O
O
O
N
O
O
P
O
O
P
O
P
O
O
OH
OH
O
FIGURE 1.17
Ju and coworkers' [33] design and synthesis of a 3
-
O
-allyl photocleavable
fluorescent nucleotide as a reversible terminator for DNA sequencing by synthesis.
Chen and coworkers [35] developed a novel method of selective deacylation using
dioxomolybdenum dichloride as a catalyst. The conditions are mild and the yields
are very high. Figure 1.20 shows more spectacular examples of removal of acyl
group in the presence of other protecting functionalities.
Padr on, Bermejo, and collaborators [36] used as simple reagent as
p
-
toluenesulfonic acid (or 10-camphorsulfonic; CSA) to selectively cleave acetates
in the presence of benzoates and
p
-bromobenzoates. The reactions are performed
in DCM/methanol at 40
◦
C and yields are high. The examples shown in Table 1.1
illustrate the methodology.
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