Buchanan David J, Dixon Darren J, Hernandez-Juan Felix A
Department of Chemistry, University of Cambridge, UK.
Org Biomol Chem. 2004 Oct 21;2(20):2932-4. doi: 10.1039/b406804c. Epub 2004 Sep 22.
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.
(S)-6-甲基δ-内酯的“裸露”阴离子对α,β-二取代硝基烯烃进行有效的氧-迈克尔加成反应，得到THP保护的亨利产物，在β-位具有优异的（95→98%的非对映体过量）立体控制，在α-位具有中等的（高达3:1）立体控制，有利于顺式非对映异构体。通过原位N-Boc保护和THP去除进行硝基还原，得到α,β-二取代乙醇胺衍生物，而用四丙基高钌酸铵处理则得到高非对映体过量的THP*保护的α-羟基酮衍生物。
