1.6- Heptadien-4-carboxylic acid

Diastereoselective iodolactonization of y, -unsaturated acids.2 Kinetic io-dolactonization of the meso-1,6-heptadien-4-carboxylic acid (1) results in two prod-... 

The iodolactonization of 1,6-heptadiene-4-carboxylic acid derivatives23 25 is a reaction capable of differentiating between the two similar double bonds in the substrate and gives significant insight into (S,R) group and facial selectivity. 

The iodolactonization of a n, .vyn-3,5-dimethyl-l,6-heptadiene-4-carboxylic acid (9) under kinetic conditions in dichloromethane, saturated aqueous sodium hydrogen carbonate and iodine results in excellent alkene and facial selectivity. In fact, of the four possible isomeric iodolac-tones only three are isolated in a 96.5 3.1 0.4 ratio, i.c., there is >99 1 group selectivity and 97 3 distereofacial selectivity, as determined by capillary GLC and 300 MHz H-NMR analysis37. 

The iodolactonization of anti,anti-3,5-dimethyl-l,6-heptadiene-4-carboxylic acid (9) is informative for diastereofacial selectivity, in this (anti,anti)-meso form the two alkenes are enan-tiotopic, and the kinetic iodolactonization affords the corresponding lactones in a 93 7 ratio. 

Heptadienal 2,4-Heptadien-1-al (2E,4E)-Hepta-2,4-dienal (E,E)-2,4-Heptadienal (E,E)-2,4-Heptadien-1-al trans-2,trans-4 heptadienal trans,trans-2,4-Heptadienal trans,trans-2,4-Heptadien-1-al. See Heptadienal 1,6-Heptadien-3-one. SeeAllyl o-ionone Heptafluorobutyric acid CAS 375-22-4 EINECS/ELINCS 206-786-3 Synonyms Perfluorobutyric acid Classification Non-aromatic carboxylic acids Empirical C4HF7O2 Formula C3F7COOH... 

Allenic carboxylic acids, 33 - (7) 2-Hethyl-2,3-butadienoic acid, 35 - (5) 6,6-Dimethyl-3,4-heptadien-l-ol, 36 - (9) 4,4-Dimethyl--l-triraethylsilyl-l,2-pentadiene, 36 - (20) 3-Hethoxy-l,2-heptadiene,... 

Industrially, a selectivity to DAA of between 90—95% can be achieved (64). The principal by-products are mesityl oxide and acetone trimers. j W-Triacetone dialcohol [3682-91-5] can form by condensation of acetone with diacetone alcohol (116). Dehydration of ry/ -triacetone dialcohol can yield semiphorone [5857-71-6] (6-hydroxy-2,6-dimethyl-2-hepten-4-one), which may in turn ring close to form 2,2,6,6-tetramethyl-y-pyrone [1197-66-6/, or ultimately dehydrate to phorone [504-20-1] (2,6-dimethyl-2,5-heptadien-4-one) (146). Similarly, an unsymmetrical acetone trimer can also be formed which dehydrates to 2,4-dimethyl-2,4-heptadiene-6-one. These impurities complicate the high purity recovery of DAA, and are thought to be responsible for a yellow discoloration of DAA. The addition of dibasic acid (147) or nitrogen containing carboxylic or phosphonic acids (148) has been patented as refined product stabilizing agents. 

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