Ten of the twelve pairs of cranial nerves [a] emerge directly from the brainstem.  The brainstem also contains nuclei of many cranial and peripheral nerves , as well as nuclei involved in the regulation of many essential processes including breathing , control of eye movements and balance.   The reticular formation , a network of nuclei of ill-defined formation, is present within and along the length of the brainstem.  Many nerve tracts , which transmit information to and from the cerebral cortex to the rest of the body, pass through the brainstem. 
As for aldehydes , the hydrogen atoms on the carbon adjacent ("α to") the carboxyl group in esters are sufficiently acidic to undergo deprotonation, which in turn leads to a variety of useful reactions. Deprotonation requires relatively strong bases, such as alkoxides . Deprotonation gives a nucleophilic enolate , which can further react, ., the Claisen condensation and its intramolecular equivalent, the Dieckmann condensation . This conversion is exploited in the malonic ester synthesis , wherein the diester of malonic acid reacts with an electrophile (., alkyl halide ), and is subsequently decarboxylated. Another variation is the Fráter–Seebach alkylation .