Diastereoselective syntheses of [4.4]- and [4.5]-spiroketal featured tonghaosu analogs were explored. An excellent diastereoselectivity was achieved for [4.5]-spiroketals due to anomeric, steric, and perhaps Ï-Ï interactions; [4.4]-spiroketal could be obtained in good diastereoselectivity by tuning substituted pattern of the tetrahydrofuran ring.
探索了[4.4]和[4.5]螺酮的同分异构体的不对映选择性合成。由于存在异构体、空间位阻和可能的乙-乙相互作用,[4.5]螺酮的对映选择性非常好;通过调整
四氢呋喃环的取代模式,可以很好地获得[4.4]螺酮的对映选择性。