The absolutestereochemistry of TT-1 (1=rasfonin), an α-pyrone-containing natural product from a Fungi Imperfecti, Trichurus terrophilus, was determined as 5R,6R,7S,9R, and 6′S on the basis of synthesis of diastereomers of two fragments of 1 in optically active forms, and comparison of their spectral and optical data with those of natural specimens.
The novel C1-symmetric zirconocene CpCp∗ZrCl2 (Cp=C5H5, ) is a cheap, active, and effective catalyst for the asymmetric ethylmagnesiation of unactivated terminal alkenes.
新颖Ç 1 -对称茂锆CPCP *的ZrCl 2(CP = C 5 H ^ 5,)是一种廉价,有效,并且有效的催化剂未活化末端烯烃的不对称ethylmagnesiation。