Synthesis and analgesic activity of stereoisomers of 2-(3(4)-hydroxy-4(3)-methoxyphenyl)-4,7-dimethyl-3,4,4a,5,8,8a-hexahydro-2H-chromene-4,8-diols

2-(3(4)-Hydroxy-4(3)-methoxyphenyl)-4,7-dimethyl-3,4,4a,5,8,8a-hexahydro-2H-chromene-4,8-diols were found recently to possess high analgesic activity and low acute toxicity. Stereoisomers of these compounds with high optical purity were synthesized from (+)- and (-)-alpha-pinenes for the first time in this work. The structure of (4S)-4b isomer was confirmed by the XRD data. Studies of analgesic activity of the resulting products demonstrated that neither the absolute configuration nor cis- or trans-arrangement of vicinal oxygen atoms plays a significant role in manifestation of analgesic effect by these isomers, while only (4S)-4b isomer, but not (4R)-4b demonstrated the analgesic effect.