Chloromethanesulfonylethene and Dichloromethanesulfonylethene: New Reagents for Tandem Diels−Alder/Ramberg−Bäcklund Reactions
作者:Eric Block、Hak Rim Jeon、Shao-Zhong Zhang、Evgeny V. Dikarev
DOI:10.1021/ol0363523
日期:2004.2.1
Chloromethanesulfonylethene (3a) and dichloromethanesulfonylethene (3b) were prepared by oxidation of the adducts of ethylene and ClCH2SCl or Cl2CHSCl, respectively, followed by NaHCO3 dehydrochlorination. With dienes, 3a gave Diels-Alder adducts that, with base, underwent Ramberg-Backlund reaction, giving products corresponding to the adducts of the dienes and allene. Similarly, 3b gave Diels-Alder adducts that, with base in the presence of the novel chlorine source MeSO2CCl3, cleanly afforded products corresponding to the adducts of the dienes and 1,1-dichloropropa-1,2-diene.