The COS software allows students to test their knowledge of the reaction sequences described in detail in Collective Organic Syntheses, Volumes 18. This program is not intended for beginning students in organic chemistry. It is appropriate for graduate students or experienced organic chemists.

Example synthesis question and response from COS: Organic Synthesis Drills.

The program contains 2116 questions divided into drills of about 50 questions each. Each question presents starting materials(s) and reagent(s) used. Four compounds are displayed and the user is invited to choose the one that was the reported product of the reaction sequence. When a correct choice is made, the name used by Collective Organic Syntheses for that product is displayed along with the percentage yield.

Some incorrect choices represent minor products of the reactions and appropriate comments are given. Other choices are compounds that were not reported, but might well have been expected based upon reasonable reaction mechanisms consistent with the reactants. But there are also choices that could come only from fantastic transformations, incredible rearrangements, or amazing ring closures. Comments with these vary from No to the inclusion of helpful hints. No other detailed help is provided except that each question shows the page and volume number of Collective Organic Syntheses from which the question was derived. A scoring algorithm is included for the student's convenience, but the results are not recorded or saved.