The first chemoselective transformations of oridonin (I) to eriocalyxin B (II), dehydroeriocalyxin A (III) and their analogs-14-hydroxyeriocalyxin B (IV) and 14-hydroxydehydroeriocalyxin A (V) are described. The overall yield of II and III from I is 11 and 10% in six and seven steps, resp. The overall yield of IV and V from I is 57 and 49% in four and five steps, resp.

Key words: CRYSTAL STRUCTURE DETERMINATION, PHOSPHORUS CHLORIDE, INFRARED SPECTROPHOTOMETRY, ELEMENTAL ANALYSIS, IRON COMPLEX, PROTON MAGNETIC RESONANCE SPECTROMETRY, CARBONYL COMPOUNDS, BENZOYL CHLORIDE P, BRIDGE COMPOUNDS, ELECTROPHILIC REACTION