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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

Sažetak

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.

Ključne riječi

Hrčak ID:

176346

URI

https://hrcak.srce.hr/176346

Datum izdavanja:

25.6.1987.

Posjeta: 864 *