Ferenc Dutka Department for Pesticide Research, Central Research Institute for Chemistry, Hungarian Academy of Sciences, P.O. Box 17, H-1525 Budapest, Hungary Z. Naturforsch. 46c, 805 — 809 (1991); received March 26, 1991 Safeners, Prosafeners, Acetals, Ketals, MG-191 Acetals and ketals involving a dichloromethyl group on their central carbon atom were found to be active or highly active as saf...

Prodrug-oriented molecular design was attempted for the potent acyclic neonicotinoid insecticide, clothianidin (1-(2-chloro-5-thiazolylmethyl)-3-methyl-2-nitroguanidine). Molecules bearing a CH2COCH2 bridge linking the 1,3-NH ends of clothianidin or their acetals would possibly be hydrolyzed, regenerating the mother compounds. This strategy was used to prepare seven acetals of clothianidin-base...

Four recently launched cyclic glycerol acetals or ketals are evaluated as bio-based solvents. Three of them are industrially available and result from the condensation of glycerol with formaldehyde, acetone and isobutyl methyl ketone. The fourth is under development and is prepared by the reaction of glycerol with benzaldehyde under heterogeneous acidic catalysis. Their solvent properties are e...

Four-component Mannich reactions subsequently followed by an intramolecular oxo-Michael addition were developed to efficiently produce chiral cyclic acetals with high diastereoselectivity and enantioselectivity.

Novel unsaturated ethers were synthesised in good yields starting from sucrose,using a two-step mild and efficient procedure based on the Gassman method, which consists in forming a vinyl group by the elimination of ethanol from mixed acetals with trimethylsilyl trifluoromethanesulfonate in the presence of alkyl amines. Mixed acetals are readily obtained from the corresponding alcohols and ethy...

A clean, practical and environmentally friendly synthesis in a homogeneous system has been developed for α-oxoketene S,S-acetals. A mixture of [Bmim]Cl and water was used as medium. The best economical and practical molar ratio of [Bmim]Cl to substrate was 4 to 1. With various types of 1,3-dicarbonyl compounds as substrate, the corresponding α-oxoketene S,S-acetals have been prepared under mild...

The maturation of Madeira wines usually involves exposure to relatively high temperatures which affect the aroma and flavour composition leading to the formation of the typical and characteristic bouquet of these wines. The formation of heterocyclic acetals (1,3-dioxanes and 1,3-dioxolanes) was investigated in order to determine levels and for possible use as indicators of wine age. The results...

The synthesis of deep cavitands with functionalized acetals as a fourth-wall is described. Recognition properties and stabilities of the complexes of two representative cavitands with aliphatic, aromatic, carbocyclic and adamantane guests were evaluated by NMR methods.

Substituted silacyclohexenes, generated through silene-diene [4 + 2] cycloaddition reactions, undergo Lewis acid promoted Sakurai type reactions with acetals to afford, following oxidation of the resultant fluorosilane, 1,4-diols with four contiguous chiral centres.