We describe a short total synthesis of ajoene, a major biologically active constituent of garlic. The instability of allicin as the only other known alternative starting material has led to the development of a reliable procedure for the synthesis of ajoene from simple building blocks that is also suitable for upscale operations.

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The enantioselective carbolithiation of ortho-substituted (E)-beta-methylstyrenes provides access to chiral lithiated intermediates with broad synthetic potential. Specifically, beta-methylstyrenes with o-aminomethyl, ether, and oxazoline groups have been employed in the synthesis of chiral aromatics and heteroaromatics such as isoquinolines, isoquinolinones, benzofurans, and isobenzofuranones.

Selective cyclizations of selenium electrophiles lead to either tetrahydrofurans or lactones (see scheme), depending on the counterions and additives. Modification of the selenium electrophiles allow selective cyclizations, irrespective of the reaction conditions applied.

Electrophilic cyclizations are one of the major strategies for cyclofunctionalizations of alkenes. Selective selenocyclizations can be performed by adjusting various factors in such reactions. The nature of the electrophile, the counterion, solvents, and external additives coordinating to the electrophilic species are used to control the course of such cyclizations with high degrees of efficiency. Our investigations have been extended towards stereoselective reactions using chiral selenium electrophiles. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2004)