Thermal rearrangement of 1,3-thiazolidine sulfoxides: Thiolsulfinate and thioaldehyde intermediates
作者:Hoh-Gyu Hahn、Kee Dal Nam、Heduck Mah
DOI:10.1002/jhet.5570360141
日期:1999.1
opening of the sulfoxides cis-13 and trans-14 in refluxing toluene gave the corre sponding sulfenic acids 9, 10 intermediates respectively. The sulfenic acid 9 dimerized to the thiolsulfinate 17 by dual function of the sulfenic acid as S-nucleophile/S-electrophile with loss of water while the sulfenic acid 10 was unchanged. The stereospecific recyclization of 10 to the parent sulfoxide 14 increases the
亚砜的立体有择开环的顺式- 13和反式- 14在回流的甲苯中,得到CORRE既受次磺酸9,10分别中间体。通过亚硫酸作为S-亲核试剂/ S-亲电子试剂的双重功能,亚硫酸9在不失水的情况下二聚为硫代亚磺酸盐17,而亚硫酸10没有变化。10到母体亚砜14的立体定向环化反应增加了双核的较高pi电子密度。硫代亚磺酸盐的热解17得到瞬态亚磺酸9,其再次二聚以重复该过程,并形成可溶的硫代醛21。在反应条件下不可避免地由17的水解形成的亚磺酸20催化剂的作用,或在中性条件下的噻唑18的作用下,将硫醛21转化为吡咯15。在这些重排中,酰胺羰基有助于消除相邻的氢。