TY - JOUR ID - 2180 TI - In Situ Formation of Allyl Ketones via Hiyama−Nozaki Reactions Followed by a Chromium-Mediated Oppenauer Oxidation JO - J. Org. Chem. PY - 2002 SP - 1975-1981 AU - Schrekker, H. S. AU - de Bolster, M. W. G. AU - Orru, R. V. A. AU - Wessjohann, L. A. AU - VL - 67 UR - DO - 10.1021/jo001750u AB - In Hiyama−Nozaki reactions of allylchromium with aldehydes the expected products are homoallylalcohols. However, oxidation products derived from these, predominantly allyl ketones, can be common side products. This can be explained by an Oppenauer−(Meerwein−Ponndorf−Verley)-type mechanism (OMPV-reaction). The amount of oxidation is strongly dependent on the substitution pattern of the reaction partners and the reaction conditions. An appropriate choice of these can lead to preferential formation of ketones instead of the alcohols. In addition to its synthetic usefulness, the oxidation−reduction equilibrium is of the utmost importance for the design of enantioselective Hiyama−Nozaki reactions because it is also a potential racemization pathway. A2 - C1 - Bioorganic Chemistry ER -