- PRODUCTION OF 2,4-HEXADIENOIC ACID AND 1,3-PENTADIENE FROM 6-METHYL-5,6-DIHYDRO-2-PYRONE
-
Described is a method of making sorbic acid, pentadiene, or 3-penten-2-one. The method includes partially hydrogenating 4-hydroxy-6-methyl-2-pyrone (HMP) to yield 5,6-dihydro-4-hydroxy-6-methyl-2H-pyran-2-one (4-DHMMP). Then, if 3-penten-2-one is desired, thermally decomposing the 4-DHMMP to yield 3-penten-2-one. If sorbic acid or pentadiene are desired, the 4-DHMMP is hydrogenated to yield 4-hydroxy-6-methyltetrahydro-2-pyrone (4-HMTHP). The 4-HMTHP is then dehydrated by contacting it with a solid acid catalyst to yield parasorbic acid (PSA). The PSA can then be ring-opened by contacting it with a solid acid catalyst. The reaction conditions of the ring-opening reaction can be controlled to yield sorbic acid and/or pentadiene.
- -
-
Page/Page column 5
(2012/05/20)
-
- Mechanism of hydrolysis and structure-stability relationship of enaminones as potential prodrugs of model primary amines
-
The objective of this work was to investigate the chemistry and the structure-stability relationship of enaminones (a class of enamines formed between a primary amine and a 1,3-dicarbonyl compound) and to evaluate their potential usefulness as prodrugs of primary amines. The acid-catalyzed degradation of the enaminones was found to be very sensitive to minor differences in the structure of the 1,3-dicarbonyl compound used to form the enaminone, but relatively insensitive to changes in the amine portion of the enaminones. A correlation was found between the rate of enaminone hydrolysis and the pK(a) of the 1,3-dicarbonyl compound, suggesting that the rate-controlling step in the hydrolysis of the enaminones was the proton addition to the vinyl carbon of the enaminone. Enaminones formed with cyclic 1,3-dicarbonyl compounds were significantly more stable than those formed with structurally similar acyclic compounds. Based on chemical stability considerations alone, enaminones do not appear to be good candidates as prodrugs of primary amines. Evidence is presented, however, that enaminones formed between amines and 1,3-ketoesters or lactones may be subject to enzyme-catalyzed degradation. Further research on the design of enaminones destabilized by a triggering enzymatic event that results in the loss of conjugation (e.g., ester or lactone hydrolysis or an oxidation/reduction event) may prove worth pursuing.
- Naringrekar,Stella
-
p. 138 - 146
(2007/10/02)
-
- Enaminones as potential prodrugs of primary and secondary amines
-
Novel enzymatically labile enaminones useful as potential prodrugs of primary and secondary amines are disclosed. Also, disclosed herein are compositions comprising said amines and methods of administering said composition to warm-blooded animals.
- -
-
-