Abstract
Several organic compounds especially cyclic compounds containing double or triple bond and carbonyl compounds, aromatic compounds were brominated by employing several well-known reagents e.g., Nbromosuccinimide, bromine in acetic acid, ammonium bromide, hydrogen peroxide in acetic acid, carbon tetrabromide, phosphorous tribromide, 2,4,4,6-tetrabromocyclohex-2,5-dienone. The resulting compounds were utilized for the synthesis of several sesquiterpenes e.g., eudes-4(14)7(11)-diene-8-one, glutinosone, platyphyllide, occidentalol, drim-8-ene-7-one, cacalol, elemol, bakkenolide A, 10-bromo-α-chamigrene, allolaurintero, aplysin, costunolide, humulene, bisabollenes, bicycloelemene, occidol, longifolin, juvabiols, futronolide, etc. The importance of some of the mentioned reagents for bromination was also observed during the synthesis of the plant hormone abscisic acid, marine terpene synderol and α-asarone, a substance of potent hypolipidemic activity. The compounds obtained by bromination were likewise utilized for the synthesis of diterpenes like taxodione, spat-13,17- dien-5-ol and gibberellin A12. Some of these bromo compounds were utilized for the synthesis of many substituted tetralones, tetralins and naphthalenes e.g., 6,7-dimethoxy-2-tetralone, 8-methyl-7-methoxy-1-tetralone, 8- methyl-1-tetralone, 1,4-dimethoxy-1-acetylnaphthalene, 7-methoxy-1-naphthylacetic acid, 5,6-dimethoxy- 1,2,3,4-tetrahydronaphthalene-2-carboxylic acid, 2-hydroxy-1,4-dimethoxynaphthalene which were utilized for the synthesis of many bioactive compounds.
Dedicated with profound regards to Dr. Michael Kolb, ex-editor of Synthetic Communications
Keywords: N-bromosuccinimide (NBS), bromine in acetic acid, carbon tetrabromide, ammoniun bromide, hydrogen peroxide, phosphorous tribromide, silver tetrafluoroborate, bromine.
Graphical Abstract