Aziridines as Precursors for Chiral Amide-Containing Surfactants

Optically active aziridines can be used as precursors in the synthesis of several enantiopure amide-containing surfactants. Acylation of the aziridines is a convenient method for both the activation of the aziridine ring and the introduction of the hydrocarbon chain. The regioselectivity of the ring-opening reactions using dibenzyl phosphate could be controlled by varying the reaction temperature. In this way both regioisomers of the phospholipid analogues could be obtained. In the course of these experiments, an unprecedented rearrangement of α-acylamino phosphotriesters was observed. A mechanism for this group exchange reaction was proposed based on the compared reactivities of related compounds and FT-IR spectroscopic data. Application of high pressures (12 kBar) for the ring opening of the activated aziridines with imidazole led to the efficient formation of the desired surfactant with complete regioselectivity.