E. Kiehlmann, P. Loo
Jun 1, 1969
Citations
0
Influential Citations
5
Citations
Journal
Canadian Journal of Chemistry
Abstract
In the presence of sodium acetate as catalyst, chloral hydrate undergoes a mixed aldol condensation with aliphatic and alicyclic ketones in acetic anhydride as solvent. Contrary to previous literature reports, reaction occurs at both the methyl and the methylene group in α-position to the carbonyl group of butanone, to give a mixture of 1,1,1-trichloro-2-hydroxy-4-hexanone (1) and 1,1,1-trichloro-2-hydroxy-3-methyl-4-pentanone (2a and 2b, diastereomers). 3-Pentanone, cyclohexanone, and 4-methyl-2-pentanoneyield 1,1,1-trichloro-2-hydroxy-3-methyl-4-hexanone (3a and 3b, diastereomers), 2-(1-hydroxy-2,2,2-trichloroethyl-) cyclohexanone (4a and 4b, diastereomers), and 1,1,1-trichloro-2-hydroxy-6-methyl-4- heptanone (5), respectively. Compound 5 is the exclusive product formed from chloral hydrate and 4-methyl-2-pentanone since attack at the methylene group is sterically hindered. The low-melting diastereomers 2a, 3a, and 4a which have not been characterized before, exhibit strong intramolecular hydrogen bondi...