Asymmetric Cyclopropanation Using New Chiral Auxiliaries Derived from D-Fructose
摘要:
Acetals of alpha,beta-unsaturated aldehydes with 3-O-alkylated derivatives of 1,2-O-isopropylidene-beta-D-fructopyranose and 1,2-O-isopropylidene-beta-D-psicopyranose, which are readily available from D-fructose, were cyclopropanated with Et(2)Zn and CH2I2 with good diastereoselectivity. The effects of structure of the acetals on enantioselectivity were examined.
The desulfurization of 1,1-bis(phenylthio)-2-alkynes with the titanocene(II) species Cp2Ti[P(OEt)3]2 in the presence of 1-alkenes produced 1-alkyn-1-ylcyclopropanes in good yields.
在1-烯烃存在下,用钛茂(II)物种Cp 2 Ti [P(OEt)3 ] 2对1,1-双(苯硫基)-2-炔烃进行脱硫,生成了1-炔基-1-基环丙烷产量。