Chemistry Reference
In-Depth Information
O
O
+
HS
OH
HO
hv, DMPA
CH
3
CN, RT
O
O
O
+
HS
OH
HO
O
S
OH
hv, DMPA
CH
3
CN , R T
HO
O
O
(HOOC-O
t
-COOH)
HO
S
OH
(HOO C-U-COOH)
O
O
O
O
+3
HS
OH
O
O
O
hv, DMPA
CH
3
CN, RT
O
O
O
S
OH
O
O
O
S
OH
COOH
COOH
COOH
O
O
Un
O
S
OH
Scheme 4.16 Using the thiol-ene reaction to synthesize di- and trifunctional carb-
oxylic acids.
48
O
O
Δ
-AcOAc
Ac-O-Ac
-HOAc
HOOC-O
t
-COOH
AcOOC-O
t
-COOAc
Ac
Ac
O
Ot
O
n
Scheme 4.17 Formation of an anhydride polymer by acetylation and melt conden-
sation. Several polymeric anhydrides were prepared, using the di- and
tricarboxylic acid compounds from Scheme 4.16.
48
The melting points were around 50-70 1C, but they depended on the pre-
treatment (annealing). The decomposition (5 wt% loss) started at 300 1Cor
higher.
The same group also synthesized amine-esters using the thiol-ene click
reaction.
52
The solubility of the cysteamine salt was better than the solubility
of cysteamine, and the yields were better. The undecylenic acid methyl ester
gave an 85% isolated yield of the product, without use of an initiator. The
less reactive methyl oleate and methyl erucate gave 75% and 66% isolated
yields, and the reaction needed to be initiated with UV light and DMPA
(see Scheme 4.20).
