Asymmetric cycloaddition routes to both enantiomers of trans-9,10-dihydro-9,10-ethanoanthracene-11,12-dicarboxylic acid
作者:Linda Thunberg、Stig Allenmark
DOI:10.1016/s0957-4166(03)00172-1
日期:2003.5
S)-enantiomer and di-(+)-iso-menthyl fumarate the (+)-(R,R)-enantiomer of the acid. The other fumarates, obtained from (−)-borneol, (+)-fenchol and (−)-isopulegol, likewise gave the (−)-(S,S)-enantiomer of the acid. The absolute stereochemistry of the products was confirmed via a single crystal X-ray crystallographic structure determination of the brucine salt of the (−)-(S,S)-enantiomer.
由一系列旋光性醇制备的富马酸酯在路易斯酸催化的蒽的不对称环加成反应中用作亲二烯体。该反应得到高产率和二酯环加成产物的de-s,并且酸水解可以在仅产生约10%外消旋化的条件下进行。该反应形成了双环二羧酸的两种对映体的有价值的合成途径,因为富马酸二(-)-薄荷基薄荷酸酯生成了富马酸的(-)-(S,S)-对映异构体和富马酸二-(+)-异薄荷基酯。酸的(+)-(R,R)-对映异构体。得自(-)-冰片,(+)-苯酚和(-)-异胡薄荷醇的其他富马酸酯也给出了(-)-(S,S)-酸的对映体。通过对(-)-(S,S)-对映异构体的浅紫红色盐的单晶X射线晶体结构测定证实了产物的绝对立体化学。