0000000000328560
AUTHOR
Luisa Ceita
ChemInform Abstract: o-Nitroaryldioxolanes for Protection of Pheromones. Study of the Photodelivery of Carbonyl Compounds.
o-Nitrophenyldioxolanes 1 to 12 have been prepared and the rate of their photocleavage determined. Steric congestion in the molecule causes a decrease of the reaction rate. The decrease in the rate...
O-Nitroaryldioxolanes for Protection of Pheromones. Study of the Photodelivery of Carbonyl Compounds
o-Nitrophenyldioxolanes 1 to 12 have been prepared and the rate of their photocleavage determined. Steric congestion in the molecule causes a decrease of the reaction rate. The decrease in the rate is especially important in the presence of a nitro group in a second phenyl ring.
Dienediolates of unsaturated carboxylic acids in synthesis. Aldehydes and ketones from alkyl halides, by ozonolysis of β,γ-unsaturated α-alkyl carboxylic acids. The role of a tertiary amine in the cleavage of ozonides
Abstract A convenient two-step procedure for a two carbon homologative conversion of alkyl halides into aldehydes and methyl ketones by α-alkylation of unsaturated carboxylic acids, followed by ozonolysis is developed and applied to the synthesis of ω-chloro aldehydes. Triethylamine is superior to dimethyl sulfide or triphenylphosphine for cleavage of the ozonides, except when aldol condensation side reactions require use of protic solvents and iodide salts. Cleavage of the ozonides by triethylamine is shown to occur mainly through a reductive process.
ChemInform Abstract: Trienediolates of Hexadienoic Acids in Synthesis. Addition to Unsaturated Ketones. A Convergent Approach to the Synthesis of Retinoic Acids.
Abstract The regioselectivity of the addition of the lithium trienediolates generated from hexa-2,4dienoic acids 1 and 2 or the dihydropyran-2ones 4 and 5 to unsaturated ketones 6 is studied. Equilibration conditions favour reaction of the trienediolates through their ω carbon, and the ketones according to 1,2- and 1,4-additions. β-Ionone 6a and the aryl-butenone 6b lead to the 1,2-ω-adducts 8 , which undergo a facile acid catalyzed dehydration to retmoic acids 11 . On reaction with the unsaturated ketone 6b or with the aryl ketones 21 , the trimethyldihydropyran-2one S leads to γ-adducts derived from deprotonation of the chain methyl mbstituent along with the 1,4-ω-adducts.
Trienediolates of hexadienoic acids in synthesis. Addition to unsaturated ketones. A convergent approach to the synthesis of retinoic acids
Abstract The regioselectivity of the addition of the lithium trienediolates generated from hexa-2,4dienoic acids 1 and 2 or the dihydropyran-2ones 4 and 5 to unsaturated ketones 6 is studied. Equilibration conditions favour reaction of the trienediolates through their ω carbon, and the ketones according to 1,2- and 1,4-additions. β-Ionone 6a and the aryl-butenone 6b lead to the 1,2-ω-adducts 8 , which undergo a facile acid catalyzed dehydration to retmoic acids 11 . On reaction with the unsaturated ketone 6b or with the aryl ketones 21 , the trimethyldihydropyran-2one S leads to γ-adducts derived from deprotonation of the chain methyl mbstituent along with the 1,4-ω-adducts.