PALOMO, CLAUDIO;AIZPURUA, JESUS M.;GARCIA, JESUS M.;PICARD, JEAN PAUL;DUN+, TETRAHEDRON LETT., 31,(1990) N3, C. 1921-1924
作者:PALOMO, CLAUDIO、AIZPURUA, JESUS M.、GARCIA, JESUS M.、PICARD, JEAN PAUL、DUN+
DOI:——
日期:——
A Contribution to the Asymmetric Synthesis of 3-Amino β-Lactams: The Diastereoselective [2+2] Cycloaddition Reaction of Chiral Aminoketene Equivalents with Enolizable Aldehyde-Derived Imines
作者:Claudio Palomo、Jesus M. Aizpurua、Marta Legido、Antonia Mielgo、Regina Galarza
DOI:10.1002/chem.19970030909
日期:1997.9
AbstractN‐[Bis(trimethylsilyl)methyl]imines 9 show unique chemical properties when compared with conventional imines. Their reaction with optically pure aminoketenes derived from dehydrochlorination of 14 and 15 affords the corresponding 3‐amino‐4‐alkyl‐β‐lactams 16 and 17 in good yields and high diastereoselectivities. The mild deprotection of bis(trimethylsilyl)methyl‐ and phenyloxazolidinone moieties with, respectively, cerium(IV) ammonium nitrate and lithium/ammonia or hydrogen/Pd(OH)2 allows the preparation of a variety of β‐lactam antibiotic building blocks.
A concise formal approach to the oxacephem skeleton from an intramolecular Peterson type olefination of N-[bis(trimethylsilyl)methyl]-β-lactams.
作者:Claudio Palomo、Jesu´s M. Aizpurua、Jesu´s M. Garcta、Jean Paul Picard、Jacques Dunogue´s
DOI:10.1016/s0040-4039(00)98818-x
日期:1990.1
A convenient synthesis of precursors of bicyclic β-lactam compounds from 4-acetoxy-1-(bistrimethylsilylmethyl)azetidin-2-ones prepared in few steps from the acid chloride-imine approach is described. A novel method to construct a bicyclic β-lactam ring system through an intramolecular Peterson type alkenation catalyzed by fluoride ion is also made.