erythro-3-alkyl-2-hydroxypropionate unit in (4) is predominantly obtained via the reaction of but-2-enylstannane (2a) with glyoxylate esters (3) while the threo-isomer (5) is preferentially produced via 9-but-2-enyl-9-borabicyclo[3.3.1] nonane (2b); the former reaction has been applied to the enantioselective synthesis of verrucarinolactone (6).
(4)中的赤型-3-烷基-2-羟基
丙酸酯单元主要是通过丁-2-烯基
锡烷(2a)与
乙醛酸酯(3)的反应获得的,而苏式异构体(5)则优先通过9-生成丁-2-烯基-9-
硼环[3.3.1]
壬烷(2b); 前一种反应已应用于对
丙酮酸内酯(6)的对映选择性合成。