Тропинон: Химиялық қасиеттері мен синтезі

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| ImageFile1 = tropinone. png
| ImageFile2 = Tropinone 3D sticks. png
| IUPACName = 8 Methyl 8 azabicyclo[3.2.1]octan 3 one
| OtherNames = 3 Tropinone
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| HPhrases = Tropinone and the alkaloids cocaine and atropine all share the same tropane core structure. Its corresponding conjugate acid at pH 7.3 major species is known as tropiniumone.

The first synthesis of tropinone was by Richard Willstätter in 1901. It started from the seemingly related cycloheptanone, but required many steps to introduce the nitrogen bridge; the overall yield for the synthesis path is only 0.75%. Willstätter had previously synthesized cocaine from tropinone, in what was the first synthesis and elucidation of the structure of cocaine.

The 1917 synthesis by Robinson is considered a classic in total synthesis due to its simplicity and biomimetic approach. Tropinone is a bicyclic molecule, but the reactants used in its preparation are fairly simple: succinaldehyde, methylamine and acetonedicarboxylic acid (or even acetone). The synthesis is a good example of a biomimetic reaction or biogenetic type synthesis because biosynthesis makes use of the same building blocks. It also demonstrates a tandem reaction in a one pot synthesis. Furthermore, the yield of the synthesis was 17% and with subsequent improvements exceeded 90%. In place of acetone, acetonedicarboxylic acid is known as the "synthetic equivalent" the 1,3 dicarboxylic acid groups are so called "activating groups" to facilitate the ring forming reactions. The calcium salt is there as a "buffer" as it is claimed that higher yields are possible if the reaction is conducted at "physiological pH".

IBX dehydrogenation (oxidation) of cycloheptanone (suberone) to 2,6 cycloheptadienone [1192 93 4] followed by reaction with an amine is versatile a way of forming tropinones. The mechanism evoked is clearly delineated to be a double Michael reaction (i. e. conjugate addition).

The reduction of tropinone is mediated by NADPH dependent reductase enzymes, which have been characterized in multiple plant species. These plant species all contain two types of the reductase enzymes, tropinone reductase I and tropinone reductase II. TRI produces tropine and TRII produces pseudotropine. Due to differing kinetic and pH/activity characteristics of the enzymes and by the 25 fold higher activity of TRI over TRII, the majority of the tropinone reduction is from TRI to form tropine.