Addition of allylstannanes to an oxy-stabilized carbenium ion on a 1,7-dioxaspiro[5.5]undecane ring system
作者:Margaret A. Brimble、Fares A. Fares、Peter Turner
DOI:10.1039/a707607j
日期:——
The nucleophilic addition of allylstannanes to (2R*,5S*,6S*)-2-acetoxy-5-benzyloxy-1,7-dioxaspiro[5.5]undecane 1 has been studied. The optimum conditions involve the use of trimethylsilyl trifluoromethanesulfonate in dichloromethane at –78 °C. In the examples studied, substitution of the acetoxy group at C-2 proceeds from an axial direction, however, subsequent ring flipping of the substituted ring occurs as well affording allylated products in which the substituents at both C-2 and C-5 are equatorial.
研究了丙烯基锡化合物对(2R*,5S*,6S*)-2-醋酸氧基-5-苄氧基-1,7-二氧斯皮罗[5.5]十一烷1的亲核加成反应。最佳反应条件是在-78°C下,使用三甲基硅基三氟甲磺酸酯在二氯甲烷中进行。在所研究的实例中,C-2位的醋酸基团取代是从轴向进行的,然而,取代环随后发生环翻转,生成的产物中C-2和C-5的取代基均为赤面。