Preparation of polyfunctional allenic alcohols by the regioselective addition of functionalized propargylic chromium (III) organometallics to carbonyl compounds

K Belyk, MJ Rozema, P Knochel

Index: Belyk, Kevin; Rozema, Michael J.; Knochel, Paul Journal of Organic Chemistry, 1992 , vol. 57, # 15 p. 4070 - 4074

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Citation Number: 23

Abstract

The reaction of propargylic halides 1 (X= C1, Br) with an aldehyde or ketone (0.67 equiv) in the presence of CrClz (2.0 equiv) and LiI (2 equiv, necessary if X= C1) affords allenic alcohols 3 with excellent regioeelectivities (3-6% of the regioisomeric acetylenic alcohol 4 is formed) and in good yields (68-90%). Interestingly, this method allows the generation of highly functionalized intermediate propargylic chromium organometallics contained an ...