ISSN:
0170-2041
Keywords:
Enones
;
Trityl enones
;
Michael additions
;
EPC synthesis
;
Pentanols, 4,5-diamino-
;
Ethylenediamine, enantiomerically pure N,N-acetals of
;
Propionic acids, 2,3-diamino-
;
Chemistry
;
Organic Chemistry
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Chemistry and Pharmacology
Notes:
The enolates A and C of t-butyl (R)-2-t-butyl-3-methyl-4-oxo-1-imidazolidinecarboxylate (1, Boc-BMI) and of 1-t-butyl 5-methyl (2R,5S)-2-t-butyl-3-methyl-1,5-imidazolidinedicarboxylate (3) and t-butyl (R)-2-t-butyl-5-lithio-3-methyl-1-imidazolidinecarboxylate (B, from 2) add in a Michael-type reaction to trityl enones (E, 4, 5). With one exception (product 8) a single diastereoisomer is formed (≫98% ds). - In two cases (6, 10), the crystal structures of the products are determined by X-ray diffraction. The steric course of the reactions (the relative topicity is unlike with the enolates) is discussed and compared with that of other conversions of the same reagents. - The trityl groups of two adducts (8 and 9) are cleaved off by treatment with LiBH4/cat. LiBHEt3 to give diaminopentanol derivatives (12 and 13).
Additional Material:
1 Ill.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/jlac.1992199201188
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