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The transesterification of used soybean oil with methanol was carried out over hydrated lime (HL), Ca(OH)2, and its decomposition products in the 200–500 °C range. The catalysts were characterized by X-ray powder diffraction (XRD), thermogravimetric analysis, and scanning electron microscopy. The XRD powder patterns demonstrated that the pristine sample consisted of a mixture of calcium hydroxide and calcite. It was noticed that the coexistence of CaO, Ca(OH)2, and CaCO3 remained up to 400 °C. At 500 °C, Ca(OH)2 is transformed into CaO so that this and CaCO3 are the only remaining phases. In the transesterification reaction, the influence of calcination temperature, reaction time, catalyst amount, methanol:oil ratio, and reaction temperature was studied. Full conversion of the raw materials into biodiesel (BD) was obtained with the fresh HL. In order to determine any change in the solid, it was recovered after 10, 30, and 60 min of reaction and analyzed by XRD analysis. Only Ca(OH)2, CaCO3, and traces of monohydrocalcite were detected. From the results it was demonstrated that the active phase for biodiesel production was calcium hydroxide. Furthermore, the catalyst was used up to three times without deactivation. A simple, economic, and environmentally friendly way to obtain biodiesel was developed considering (a) used soybean oil, considered waste, was employed as raw material, (b) hydrated lime is cheap and readily available, and (c) full conversion of the raw materials into BD was achieved with the as-received HL.

The generation of diastereomerically enriched secondary benzyl propargyl alcohols by the asymmetric addition of ortho-sulfinylbenzyl carbanions to sulfonylacetylene derivatives via formation of a Csp-Csp bond is described. This reaction proceeds through an unusual α-attack (anti-Michael addition) of the ortho-sulfinylbenzyl carbanions, followed by elimination of the arylsulfonyl moiety. The scope of this alkynylation reaction is also discussed. Moreover, the development of a new approach for the synthesis of optically active tertiary benzylpropargyl alcohols is described, discussing the possible stereocourse of the reaction so as the influence of the ether 18-crown-6 and steric importance of acetylenic substituent.

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H and 13 C spectra for all new compounds and X-ray data for 2e′ and 7a (PDF)Accession Codes CCDC 1875997 and 1875998 contain the supplementary crystallographic data for this paper. These data can be obtained free of charge via www.ccdc.cam.ac.uk