Studies on the constituents of Juglans species. I. Structural determination of (4S)- and (4R)-4-hydroxy-alpha-tetralone derivatives from the fruit of Juglans mandshurica MAXIM. var. sieboldiana MAKINO.

Four enantiomerically pure new alpha-tetralones, (4S)- and (4R)-5-hydroxy-4-methoxy-alpha-tetralones and (4S)- and (4R)-5,8-dihydroxy-4-methoxy-alpha-tetralones were isolated, together with five known ones, (4S)- and (4R)-4,8-dihydroxy-alpha-tetralones, (4S)-4,8-dihydroxy-5-methoxy-alpha-tetralone and (4S)- and (4R)-4-hydroxy-alpha-tetralones, from the fruit of Juglans mandshurica MAXIM. var. sieboldiana MAKINO. Their structures were established on the basis of spectral analysis. To the best of our knowledge, this is the first isolation of the (4R)-4-hydroxy-alpha-tetralone derivative from Juglans species.