Аннотация:
Heating the 16-E-oxime of isosteviol (ent-16-E-hydroxyiminobeyeran-19-oic acid) with concentrated hydrochloric acid (or 25% H2SO4) at 110 °C leads to the formation of lactone of 4α-carboxy-13α-hydroxy-13,16-seco-ent-19-norbeyeran-16-oic acid as the main product, whereas approximately equal quantities of this lactone and lactam of 4α-carboxy-13α-amino-13,16-seco-ent-19-norbeyeran-16-oic acid are formed by heating the 16-E-oxime of isosteviol with concentrated hydrochloric acid in an ampoule at 180 °C.