Download (4Mb) - Etheses - Saurashtra University

Chapter – 4 Studies on different types of reactions…..
However, reactions using salicylaldehyde or its analogues multicyclic
compounds were obtained either solely or in addition to salicylidene
derivatives of type as shown in Fig. 4.18. 284
The proportions of the products were dependent on reaction conditions
used e.g. when salicylaldehyde and 4-hydroxycoumarin refluxed in ethanol; a
dimeric type of structure in addition to benzylidene derivative was obtained.
285
When two moles of salicylaldehyde were reacted with 4hydroxycoumarins,
it gave appropriate benzylidene derivative only (Fig. 4.19).
However, one mole of salicylaldehyde with two moles of 4-hydroxycoumarin
gave the dicoumarinyl structure. 286 (Fig. 4.20)
2
+
O O
OH
CHO
OH
CHO
OH
+
O O
OH
Fig. 4.18
Fig. 4.19
O O
O O
Department of Chemistry, Saurashtra University, Rajkot – 360 005 210
OH
O
O
+
O
O
O
O
O
OH
OH