Improving ready biodegradability testing of fatty amine derivatives.

This study assesses the biodegradation potential of a number of fatty amine derivatives in tests following the OECD guidelines for ready biodegradability. A number of methods are used to reduce toxicity and improve the bioavailability of the fatty amine derivatives in these tests. Alkyl-1,3-diaminopropanes and octadecyltrimethylammonium chloride are toxic to microorganisms at concentrations used in OECD ready biodegradability tests.

Differentially-protected steroidal triamines; scaffolds with potential for medicinal, supramolecular, and combinatorial chemistry.

Cholic acid 2a has been converted into two new orthogonally-protected triamino scaffolds, 13 and 14. The synthesis proceeds via the bis-Boc-NH-substituted azide 10, for which an improved preparation is described. After removal of the Boc groups, the two axial amines are differentiated through a novel monoprotection employing 1-(2-nitrobenzenesulfonyloxy)-benzotriazole 29.

Enolization of chiral alpha-silyloxy ketones with dicyclohexylchloroborane. Application to stereoselective aldol reactions.

[reaction: see text]Comprehensive analysis of the enolization of alpha-silyloxyketones by Chx2BCl/R3N has allowed us to design stereoselective Chx2BCl-mediated aldol processes that afford syn or anti aldol products and to disclose a hypothesis that accounts for the subtle effects that determine their enolization.