Key points are not available for this paper at this time.
The total synthesis of the spermidine alkaloid, (+)-(S)-dihydroperiphylline, is described. The key reactions in the present strategy are enantioselective aldol-type reaction of imines with ketene silyl acetals promoted by chiral BLA (Brønsted acid assisted chiral Lewis acid) and boron-templated cyclization of triamino esters.
Ishihara et al. (Sun,) studied this question.