A robust and scalable procedure for the palladium-catalyzed dynamic kinetic asymmetric transformation of 3,4-epoxy-1-butene into (2R)-3-butene-1,2-diol with water as the cosolvent is reported. Examination of the effects of solvent and temperature led to the identification of conditions that permitted use of 0.025 mol % catalyst, providing (2R)-3-butene-1,2-diol in 84% isolated yield and 85% enantiomeric excess. Subsequent Heck reactions with a diverse range of coupling partners are described and the influence of their electronic nature on maintaining the enantiopurity of the diol is discussed. E nhanced drug efficacy, more economic use of resources, and, above all else, ever more stringent regulatory policies have all contributed to an increased demand from the pharmaceutical industry for single-enantiomer compounds. This has been a major driving force within the chemical community for the development of novel methods for the asymmetric synthesis of a myriad of chiral building blocks. Single-enantiomer vinylglycols, such as (2R)-3-butene-1,2-diol, (R)-1, are versatile polyfunctional chiral synthons that can be can be manipulated in a highly stereo-and chemoselective manner. The utility of 1, in particular, has been aptly demonstrated in the synthesis of a wide variety of chiral building blocks (1). Furthermore, 1 has been used as an intermediate in the preparation of pharmaceutical agents in a wide variety of therapeutic areas such as HIV protease inhibitors (2), immunosuppression (3), and oncology (4). A number of approaches to the synthesis of enantiomerically enriched 1 based on the use of a chiral auxiliary (5), chiral-pool starting materials (6, 7), and resolution have been reported (8)(9)(10)(11)(12). However, these all suffer from factors, such as lengthy synthetic sequences or a maximum theoretical yield of 50%, making them less than ideal approaches from an industrial perspective.An alternative approach to enantiomerically enriched 1 that proceeded via asymmetric palladium-catalyzed hydrolysis of 3,4-epoxy-1-butene, 2, in which the ligand 3 was superior to ligand 4 (Fig. 1), was reported by Trost and McEachern (13). By taking advantage of the interconversion of the -allyl intermediates 5 and 6, and the chiral environment provided by the ligand-metal complex, a dynamic system is established that provides high-enantiopurity product from racemic starting material. For the diol 1 to be obtained, cocatalysis with alkylboranes was reported to be necessary, whereas in the absence of such species the cyclic carbonate 7 was the reaction product.The high synthetic and economic value of single-enantiomer 1 and the potential for its formation in high yield by using a catalytic system led us to evaluate this method for its application on an industrial scale. In this article, we report our early-phase developmental work on this reaction, which led to a highly efficient, scalable, and robust modified route to 1. Along with this development, we also report subsequent selective Heck reactions of (R)-1. The Heck reaction...