Both natural l-a-narcotise (Ⅰ) and artificial l-β-narcotise(Ⅱ) were reduced by LiAlH₄ to the α-diol (Ⅲ),m.p. 132°, [α]_D¹⁵+51.2° (CHCl₃),Al₂O₃ thin layer chromato-graphy R_f 0.63 (ether),and the β-diol (IV), m.p. 60-61°,[α]_D¹⁵-59.5° (CHCl₃),Al₂O₃ thin layer chromatography R_f 0.45 (ether),respectively. The latter was contaminated with a small amount of a-diol (Ⅲ),the yield of which was increased to 32% as the reaction time is prolonged to four hours. A copper complex (Ⅴ') could be prepared from the,β-diol (Ⅳ),but not from the a-diol (Ⅲ).From these facts, the relafive configurations of both l-α-narcotise (Ⅰ) and l-β-narcotise (Ⅱ) should be referred to as belonging to the erythro-and threo-series, respectively.