论文部分内容阅读
There is a classic experiential rule about 1,2-diol RCR1 (OH) CR1 (OH) R ( R1 = H or methyl), that is,the proton chemical shift of the α-R1 group at the hydroxyl group in the dl-isomer, in general, appears in a higher field with ca. Δ = 0. 1-0. 2 than the