3,8-Bis(methoxymethoxy)benzo[b]xanthene-12-one (1a) was reacted with n-butyllithium at −78 °C to afford the expected 1,2-adduct 1b and also the 1,4-adduct 1c. Using 2-Me-THF as the solvent afforded predominantly the 1,2-adduct 1b in 66% yield and the 1,4-adduct 1c in 5% yield. In contrast, in THF, the 1,4-adduct 1c was obtained as the major product in 47% yield and the 1,2-adduct 1b was obtained in 22% yield. As a result of many experiments, it was found that these peculiar regioselectivity is due to a variety of factors such as the kind of solvents, the organometallic species, and the reaction substrates. Among them, the difference in regioselectivity between THF and 2-Me-THF was explained using theoretical calculations.

3,8-双（甲氧基甲氧基）苯并[ b ] x吨-12-（1a）与正丁基锂在-78°C下反应，得到预期的1,2-加合物1b和1,4-加合物1c。用2-Me-​​THF作为溶剂，主要得到产率为66％的1，2-加合物1b和产率为5％的1，4-加合物1c。相反，在THF中，以1,4-加合物1c为主要产物，产率为47％，而1,2-加合物1b为主要产物。获得了22％的收率。作为许多实验的结果，发现这些特殊的区域选择性是由于多种因素引起的，例如溶剂的种类，有机金属种类和反应底物。其中，使用理论计算解释了THF和2-Me-​​THF之间的区域选择性的差异。