Stereoselective syntheses of daedalin A and quercinol, an enantiomer of daedalin A, is described. The tyrosinase inhibitory activities of daedalin A and quercinol were examined. The activity of quercinol was weaker than that of daedalin A at high concentration.Dermal hyper-pigmentation, caused by the accumulation of melanin, is initiated by oxidation of tyrosine by tyrosinase, a key enzyme of melanin biosynthesis.1 Tyrosinase inhibitors such as arbutin, kojic acid, ellagic acid, and rucinol have been used as pharmaceutical constituents of cosmetics in order to prevent hyper-pigmentation. In an effort to find new types of tyrosinase inhibitors, we have screened culture broths from mushroom mycelia for tyrosinase inhibitory activity, and found that the mycelial culture of Daedalia dickinsii showed significant activity.Based on the spectroscopic data, the bioactive compound was elucidated as (2R)-6-hydroxymethyl-2-methyl-2H-chromene, named daedalin A (1). 2,3 We have synthesized racemic 1 and it showed weaker activity than 1.3 Quercinol (2), an enantiomer of daedalin A (1), was also isolated from the fungus of Daedalea quercina by Hertweck and co-workers. 4 They reported that compound 2 showed anti-inflammatory activity. 4 It is very difficult to obtain enough amount of daedalin A (1) and quercinol (2) for the biological study because the mycelia cultures of Daedalia dickinsii and/or Daedalea quercina are limited. Thus, syntheses of 1, 2, and their analogues are important for the biological study. Especially, synthesis of 2 is required because the tyrosinase inhibitory activity of 2 has not been reported yet. Herein, we wish to describe an asymmetric synthesis of 1 and 2 and their tyrosinase inhibitory activity (Figure 1).