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Highly Stereoselective oxy-Michael Additions to Alpha,beta-Disubstituted Nitro Olefins: Asymmetric Synthesis of Pseudo-Norephedrine Derivatives and THP* Protected Alpha-Hydroxy Ketones

David J Buchanan, Darren J Dixon, Felix A Hernandez-Juan

Org Biomol Chem. 2004 Oct 21;2(20):2932-4.

PMID: 15480457

Abstract:

The "naked" anion of (S)-6-methyl delta lactol undergoes efficient oxy-Michael addition to alpha,beta-disubstituted nitro olefins to give the THP* protected Henry products with excellent (95-->98% de) stereocontrol at the beta-position and moderate (up to 3 : 1) stereocontrol at the alpha-position in favour of the syn-diastereoisomer. Nitro group reduction with in situN-Boc protection and THP* removal provides alpha,beta-disubstituted ethanolamine derivatives, while treatment with tetrapropylammonium perruthenate gives THP* protected alpha-hydroxy ketone derivatives in high diasteromeric excess.

Chemicals Related in the Paper:

Catalog Number Product Name Structure CAS Number Price
AP114615826 Tetrapropylammonium perruthenate Tetrapropylammonium perruthenate 114615-82-6 Price
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