An efficient directed Claisen reaction between tert-butyl propionate and phenyl propionate is described. This enables a practical synthesis of 6-ethyl-2,2,5-trimethyl-4H-1,3-dioxin-4-one and thereby (Z)-[(4-ethylidene-2,2,5-trimethyl-4H-1,3-dioxin-6-yl)oxy]trimethylsilane, a key building block in our synthesis of macrolide antibiotics. The three-step route elaborated for the preparation of the ...

The title compound, [Al(CH(3))(2)(C(25)H(21)N(2)O)(C(4)H(8)O)], was isolated as a minor component from a reaction mixture of the parent indolyl ligand and trimethyl-aluminum in tetra-hydro-furan. The ligands adopt a distorted tetra-hedral geometry around aluminium. Obvious hydrogen-bonding interactions are not present.

In the title compound, [Co(C(13)H(8)F(2)O)(C(3)H(9)P)(3)], the cobalt(0) atom is coordinated by three trimethyl-phosphine ligands and a π-coordinated carbonyl group of the 2,6-difluoro-benzo-phenone ligand in a distorted tetra-hedral geometry. The Co-O and Co-C distances are 1.896 (2) and 2.049 (4) Å, respectively.

A commercial nonylphenol (NP) reagent was separated into 14 fractions, NP1 to NP14 using a gas chromatograph equipped with a preparative fraction collector (GC-PFC). The identifi cation of the major components of 14 fractions was attempted by analysis of their nuclear magnetic resonance (NMR) spectra, and the estrogenicity of the isomers was tested in a recombinant yeast screen system. Eleven s...

4'-(2,6,6-Trimethyl-2-cyclohexen-1-yl)-3'-buten-2'-ketoxime-N-O-alkyl ethers have been synthesized starting from alpha-ionone, separated into their E and Z isomers and characterized on the basis of (1)H-NMR and mass spectra.