olefinic bond मीनिंग इन हिंदी

All trichothecenes contain a common 12, 13-epoxytrichothene skeleton and an olefinic bond with various side chain substitutions.
Once the 2-methylthiazole ring has been made, it is then transferred to the PKS EPOS B ( epoB ), EPOS C ( epoC ), EPOS D ( epoD ), EPOS E ( epoE ), and EPOS F ( epoF ) for subsequent elongation and modification to generate the olefinic bond, the 16-membered ring, and the epoxide, as seen in "'Figure 5 " '.
Rxn of " p "-fluorobenzyl chloride ( "'1 "') with the anion of diethylmethyl malonate ( "'2 "') gives intermediate diester ( "'3 "'), saponification of which and subsequent decarboxylation leads to "'4 "'. { Alternatively it can be formed by Perkin reaction between p-fluorobenzaldehyde and propionic anhydride in the presence of NaOAc, followed by catalytic hydrogenation of the olefinic bond using a palladium on carbon catalyst .}