Stereochemical assignment of naturally occurring 2,3-epoxy-2-methylbutanoate esters.

Natural and Synthetic Materials with Insect Hormone Activity. 5. Specific Juvenile Hormone Effects in Aliphatic Sesquiterpenes.

The juvenile hormone activity of ethyl or methyl esters of aliphatic sesquiterpenic acids with 0 to 4 double bonds was tested on 8 species of insects belonging to 5 families of Hemiptera and Coleoptera. Special attention was paid to the addition of hydrogen chloride or epoxide groups on or across the double bonds. Certain chemical changes in the molecule appear to cause a general increase of th...

Characteristic aroma compounds from different pineapple parts.

Characteristic aroma volatile compounds from different parts of cayenne pineapple were analyzed by headspace-solid phase microextraction (HS-SPME) and gas chromatography-mass spectrometry (GC/MS). The main volatile compounds were esters, terpenes, ketones and aldehydes. The number and content of aroma compounds detected in pulp were higher than those found in core. In pulp, the characteristic a...

Enantioselective syntheses of pachastrissamine and jaspine A via hydroxylactonization of a chiral epoxy ester.

A new enantioselective total synthesis of pachastrissamine (jaspine B) was achieved from a known alpha,beta-unsaturated aldehyde by utilizing Córdova's asymmetric epoxidation as the chirality-inducing step. The 2,3-cis stereochemistry of pachastrissamine was established via intramolecular epoxide ring opening of a gamma,delta-epoxy-alpha,beta-unsaturated ester intermediate coupled with oxy-Mich...

Ring Opening of Epoxy Fatty Esters by Nucleophile to Form the Derivatives of Substituted β-Amino Alcohol

The nucleophilic ring opening of epoxy fatty esters was carried out using the amino-1,2,4-triazole to yield substituted derivatives of β-amino alcohol. The synthesis of the substituted beta amino alcohols has been achieved by refluxing equimolar quantities of long chain epoxy esters (epoxy fatty esters) and 4-amino-1,2,4-triazole in dichloromethane to yield following compounds, methyl 10-(4'-am...

Coinfection Associated with Naturally Occurring Cryptosporidiosis in Broilers