1998 stereochemistry

stereochemistry (general, optical resolution)O 0030

01 - 026Asymmetric Dihydroxylation of Allylic Phosphine Oxides. —Diphenylphosphinoyl diols such as (II) are synthesized by asymmetric dihy-droxylation of allylic phosphine oxides (I) and shown to be useful syntheticintermediates (e.g. for the preparation of optically active allylic alcohols[→ (III)]). Best results with respect to yield and enantioselectivity are achievedby use of ”monomeric” ligands such as DHQD-CLB in place of the ”dimeric”phthalazine ligands contained in commercial AD-mixes. The results of thestudy are discussed in terms of the model which has been proposed by Sharplessto explain the enantioselectivity of his asymmetric dihydroxylation. —(NELSON, A.; WARREN, S.; J. Chem. Soc., Perkin Trans. 1 [old] (1997) 17,2645-2657; Univ. Chem. Lab., Cambridge Univ., Cambridge CB2 1EW, UK;EN)

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