Lactams 2-Oxazolidones, chiral

Other functional groups have been derivatized with CDAs for the purpose of analytical or preparative chromatographic resolution. Isocyanates and isothiocyanates, for example, can be derivatized with chiral amines serving as CDAs (114). Similarly, the enantiomeric piirity of isocyanates may be determined via derivatization with an optically pure alcohol (167). Isocyanates may also be derivatized with chiral 2-oxazolidones [21], Pirkle et al. described derivatization and resolution of lactams using chiral isocyanates such as 119] and [20] (224),... 

Evans et al. utilized the chiral oxazolidones to prepare optically pure 3-hydroxy-a-amino acids, - important constituents of peptides and 3-lactams. As shown in Scheme 31, an asymmetric aldol reaction using the boron enolate derived from the V-(a-haloacyl)oxazolidone (68) provides the jyn-3-hydroxy-ot-halocarbonyl derivative (69), which is converted to the ann-3-hydroxy-a-azidocarbonyl derivative (70)... 

Evans DA, Sjorgen EB. The asymmetric synthesis of (i-lactam antibiotics-I. apphcation of chiral oxazolidones in the Staudinger reaction. Tetrahedron Lett. 1985 32 3783-3786. 

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See also in sourсe #XX -- [ ]

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