Stereocontrol of C(2)-position of δ-lactones, related to Prelog-Djerassi lactone, is effected acid-catalyzed cyclization of ketene dithioacetal having an internal OH group (thermodynamic control), which is also applicable to remote asymmetric induction.
与Prelog-Djerassi内酯有关的δ-内酯C(2)位置的立体控制是通过酸催化的具有内部OH基团的
乙烯酮二
硫缩醛的环化反应(热力学控制),也适用于远程不对称诱导。