Synthesis of rhamnosylated diosgenyl glucosides as mimetics of cytostatic steroidal saponins from Ornithogalum saindersiae and Galtonia candicans.


The synthesis of mimetic of the steroid saponins 1 and 2 was investigated. As a substitute for the complex 22-homo-23-nor-steroid moieties A and B in 1 and 2 diosgenin was introduced. The silyl protected thioorthoester 20 was successfully employed for glucosylation. After selective 2--deacetylation, the glucosylated diosgenyl acceptor 23 was rhamnosylated… (More)