Croatica Chemica Acta, Vol. 60 No. 2, 1987.
Original scientific paper
Chiroptical Properties of Optically Active Thiazolidines Derived from Aldoses and Natural Mercapto-amino Acids
Zoltan Gyorgydeak
; Department of Organic Chemistry, Kossuth Lajos University, H-4010 Debrecen (Hungary)
Albert Levai
; Department of Organic Chemistry, Kossuth Lajos University, H-4010 Debrecen (Hungary)
Gunther Snatzke
; Lehrstuhl fur Strukturchemie, Ruhruniversitat D-4630 Bochum (F. R. Germany
Abstract
Optically active thiazolidines substituted at C(2) or/and C(4)
show at least 2 Cotton effects below 260 nm, and different correlations between stereochemistry and CD hold for these compounds and their N-acyl derivatives. By such N-acylation all CD-
-bands are enhanced, and the inherently chiral moiety -S-C-
-N-C(=O)- of absolute conformation shown in Figure 4 always leads to a very strong negative Cotton effect near 205nm, regardless whether C(4) carries a C(=O)X group or not. Signs, positions, and magnitudes of the other CD bands are strongly influenced by other factors, too. Such a conformation is fixed in the lactones XXVIII through XXXIV, but is also preferred for 2,4-cis-disubstitution (with a polyhydroxyalkyl group at C(2) and a carboxylic group at C(4». Exciton interactions between the N-acyl and other (C=O)X - groups do not play a decisive role.
Keywords
Hrčak ID:
176346
URI
Publication date:
25.6.1987.
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