B) HYDROXYKETONES -TRIAZOLIDINONES: 1. SYNTHESIS
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B1) Synthesis of Hydroxyalkyl - Substituted Triazolidin-3-(thi)ones

Synthesis of Hydroxy - Triazolidinones
Hydroxyalkyl substituted triazolidin-3-ones (3, Y = O) and -3-thiones (3, Y = S) were synthesized employing either a one pot procedure using the ketone (1) or a stepwise reaction sequence starting from the a-hydroxyphenylhydrazones (2). In the case of benzoin phenylhydrazone an interesting AZOALKENE TYPE REACTION occured, leading to the imidazolinethione rather than to the triazolidine-3-thione. In these compounds the hydroxy group can be easily ACYLATED. Both the triazolidin-3-ones and -3-thiones (3, Y = O/S) could be acetylated and benzoylated using appropriate methods. In the case of triazolidin-3-ones (3, Y = O) the hydroxy group could also be TOSYLATED. When treated with base the tosylated heterocyclic systems underwent an interesting RING ENLARGEMENT REACTION.

TOPICS OF: B) HYDROXYKETONES - TRIAZOLIDINONES"
  B1) Synthesis
B1.1) Azoalkene Chemistry ("Benzoin case")
B2) Acylations
B2.1) Acetylations and Benzoylations
B2.1.1) Azoalkene Chemistry (Acetoxyketones)
B2.2) Tosylation and Rearrangement
B2.2.1) Reaction Pathway
 
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