The inverse electron demand Diels-Alder reaction between 2-pyrone-3-carboxylic acid and various vinyl ethers has been performed to attain the respective products with very high diastereoselectivity, which can be used for the synthesis of cycloheixenyl nucleosides (Scheme 1). [diagram]. Scheme 1. Highly diastereoselective Inverse Electron Demand Diels-Alder reaction Primary amino alcohols derived from natural amino acids have been found to be efficient organocatalysts for the cross-aldol reaction between acetone and activated ketones, affording the respective products with high enantioselectivity (Scheme 2). [diagram]. Scheme 2. The enantioselective cross-aldol reaction catalysed by leucinol A practical, highly stereoselective, two-step protocol for the alpha-allylation of aldehydes, starting from allyltrichlorosilanes, has been developed. As a result of the kinetic resolution in each step, virtually enantio- and geometrically pure linear homoallylic alcohols were obtained in high yield from the technical grade aliyltrichlorosilanes by using only 5 mol% of a chiral catalyst (Scheme 3). [diagram]. Scheme 3. The highly enantioselective alpha-allylation of aldehydes
