eng Science and Education Publishing World Journal of Organic Chemistry 2372-2169 2017-08-15 5 1 11 16 10.12691/wjoc-5-1-3 WJOC2017513 article Francisco Sánchez-Viesca franviesca@yahoo.com 1 Reina Gómez G 1 Department of Organic Chemistry, Faculty of Chemistry, National Autonomous University of Mexico, Mexico City (CDMX), Mexico The mechanism of osazone formation has been subject of many studies during a vast period of time. However, the regiochemistry related to osazones remained an unsolved problem until recently that we presented our theoretical findings that explain the factors that direct the regiochemistry of osazone formation. Now, we wish present to the teaching community this subject, as well as a discussion of an example of mixed osazone formation. This new topic includes the factors that conduce to the main product. This communication will fill a gap existing in the Organic Chemistry textbooks. http://pubs.sciepub.com/wjoc/5/1/3/wjoc-5-1-3.pdf fructosazone hydrogen bonds 1 4-Hydrogen transfer internal oxido-reduction leaving groups Lewis bases