Activation of calcium carbide for the synthesis of acetylenic alcohols

• Main Author: Tardaguila, Alex A.
• Format: text
• Language: English
• Published: Animo Repository 2003
• Subjects: Calcium carbide; Asymmetric synthesis; Alcohol; Chemistry
• Online Access: https://animorepository.dlsu.edu.ph/etd_masteral/3172; https://animorepository.dlsu.edu.ph/context/etd_masteral/article/10010/viewcontent/CDTG003688_P.pdf
• Institution: De La Salle University

The reaction CaC2 with two equivalents of selected ketones (acetophenone, 2-methylcyclohexanone and cyclohexanone) in the presence of base (e.g. NaOH, KOH, MeOK and T-BuOK) in benzene at room temperature produces acetylenic alcohols in 10%-45% yields. The effect of the nature of counter ion of the bases on the said reactions is also investigated. Base with high percent ionic character is essential to have a strong electrostatic interaction and to break the calcium carbide lattice. KOH is the most ionic among the bases used and effectively activate CaC2 compared to MeOK and t-BuOK. LiOH was not able to activate calcium carbide because of its low percent ionic character. Iodine was also investigated but it was not able to activate CaC2 towards the ketone. The effect of sonication on the reaction of CaC2 with cyclohexanone in the presence of KOH, NaOH and T-BuOK yielded 15%-40% of bis(1-hydroxycyclohexy)ethyne. An acetylenic triol with two triple bonds and three cyclohexyl ring structures was produced in the presence of KOMe.