Copper®, in the absence of other transition metals, catalyzes the cross-coupling of (a-(acyloxy)benzyl)tributylstannanes with allylic bromides in THF in fair to good yields and with aryl/vinyl halides less efficiently or not at all. Simple (a-(acyloxy)alkyl)tributylstannanes react sluggishly even with allyl bromide. However, proximal thiosubstituents on either reaction partner dramatically enhance yields, reaction rates, and the variety of suitable educts. (a-Phthalimidoylalkyl)tributylstannanes afford protected -amino thio esters. In contrast with the Stille reaction, copper-mediated cross-couplings of -heteroatom-substituted alkyltributylstannanes proceed with complete retention of configuration via a coordinatively stabilized organocopper intermediate that can be intercepted in good yield by 1,4-conjugate addition to 2-cyclohexen-1 -one.

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Various fatty acids were fed to the yeast Dipodascopsis uninucleata UOFS Y 128, and the extracted samples were analyzed for the accumulation of 3-hydroxy metabolites with the help of electron impact gas chromatography-mass spectrometry. Fatty acids containing of 5Z,8Z-diene system (5Z,8Z,11Z-eicosatrienoic, 5Z,8Z,11Z,14Z-eicosatetraenoic, and 5Z,8Z,11Z,14Z,17Z-eicosapentaenoic acids) yielded the corresponding 3-hydroxy-all-Z-eicosapolyenoic acids. Moreover, linoleic acid (9Z,12Z-octadecadienoic acid) and 11Z,14Z,17Z-eicosatrienoic acid were converted to the 3-hydorxylated metabolites of shorter chain length, e,g., 3-hydroxy-5Z,8Z-tetradecadienoic acid and 3-hydroxy-5Z,8Z,11Z-tetradecatrienoic acid, respectively. In contrast, no accumulation of a 3-hydroxy metabolite was observed with oleic acid (9Z-octadecenoic acid), linolelaidic acid (9E,12E-octadecadienoic acid), gamma-linolenic acid (6Z,9Z,12Z-octadecatrienoic acid), and eicosanoic acid as substrate. These findings pinpoint that the 3-hydroxylation of a fatty acid in Dipodascopsis uninucleata requires a 5Z,8Z-diene system either directly or following initial incomplete beta-oxidation. Following analysis of the enantiomer composition, the arachidonic acid metabolite was identified as 3R-hydroxy-5Z,8Z,11Z,14Z-eicosatetraenoic acid, which rules out a normal beta-oxidation as biosynthetic route to this new class of oxylipins.