Chloromethanesulfonylethene and dichloromethanesulfonylethene: new reagents for tandem Diels-Alder/Ramberg-Bäcklund reactions.
[reaction: see text] Chloromethanesulfonylethene (3a) and dichloromethanesulfonylethene (3b) were prepared by oxidation of the adducts of ethylene and ClCH(2)SCl or Cl(2)CHSCl, respectively, followed by NaHCO(3) dehydrochlorination. With dienes, 3a gave Diels-Alder adducts that, with base, underwent Ramberg-Bäcklund 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 MeSO(2)CCl(3), cleanly afforded products corresponding to the adducts of the dienes and 1,1-dichloropropa-1,2-diene.
Block
Eric
E
Department of Chemistry, State University of New York at Albany, Albany, New York 12222, USA. eb801@albany.edu
Jeon
Hak Rim
HR
Zhang
Shao-Zhong
SZ
Dikarev
Evgeny V
EV