is there any trick to remember so many conversions in organic chemistry ! Please help . I dont know what to do .
There is no trick as such for the conversion reactions in organic chemistry. Try to understand the mechanism of the reactions. There are specific mechanisms for the reactions and they are somehow related too. For example if one has understood the types of nucleophilic substitution reactions SN1 and SN2 then any type of substitution with any reactant can be handled.
To get good hold on the conversations, you must remember the main chemical reactions and the synthesis of compounds like carbonyls, acids, amines etc. Do remember simple steps of preparations of compounds, and yes basic name reactions like aldol reaction helps a lot .Practice the equations by forming the product and then again forming the reactants from products, one must learn both the conditions so that at any step of conversion you are able to attempt it easily.