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Chapter – 4 Studies on different types of reactions…..
Similarly, reaction of 4-hydroxycoumarin with acetylated
aldehydohexoses in ethanol for 24 hours gave substance shown in Fig. 4.21.
287
CHO
OH
+ 2
O O
OH
Reaction between 4-hydroxycoumarin and hydroxylamine
hydrochloride gave corresponding 2, 4-chromadione-4-oximes. 288 (Fig. 4.22)
O O
OH
O O
O
+ NH 2OH . HCl
Fig. 4.20
Fig. 4.21
Fig. 4.22
O O
O O
Reaction of chlorine with 4-hydroxycoumarins in suitable solvent or
sulfuryl chloride led to the formation 3, 3-dichloro-2, 4-chromandiones. 289-293
Halogenations of 3-substituted 4-hydroxycoumarin afforded 3-chloro-2, 4chromandiones.
When 3, 3' methylenebis (4-hydroxycoumarin) was treated
with sufuryl chloride, 3, 3' methylenebis (3-chloro-2, 4-chromandione) was
isolated. (Fig. 4.23)
Department of Chemistry, Saurashtra University, Rajkot – 360 005 211
OH
CH(CHOAc) 4CH 2OAc
O
O
O
O
N
OH