Highly Selective Ring-Cleavage of Acetals Catalyzed by Phenylboron Complexes Derived from Sulfonamides of α-Amino Acids

Motoharu Kinugasa; Toshiro Harada; Katsuhiro Fujita; Akira Oku

doi:10.1055/s-1996-5332

Synlett 1996; 1996(1): 43-45
DOI: 10.1055/s-1996-5332

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Highly Selective Ring-Cleavage of Acetals Catalyzed by Phenylboron Complexes Derived from Sulfonamides of α-Amino Acids

Motoharu Kinugasa, Toshiro Harada^* , Katsuhiro Fujita, Akira Oku

^*Department of Chemistry, Kyoto Institute of Technology, Sakyo-ku, Kyoto 606, Japan, Fax 75 724 7580

Abstract

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In the presence of catalytic amount of (0.1-0.5 equiv) of phenylboron complex 5d and nucleophiles 4a-e (1.5-1.1 equiv), chiral cyclic acetals (2S,4R)-3a-d undergo efficient ring-cleavage reaction to give 7a-h with high stereoselectivity. Removal of the chiral auxiliary from the ring-cleavage products 7a-h by a two step sequence furnishes functionalized secondary alcohols 8a-h of high enantiomeric purities.

acetal - diastereoselective ring-cleavage - Lewis acid catalyzed reaction - phenyl boron complex

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