Allenyl chloromethyl sulfones, new dienophile-diene synthons. A simple iterative ring-growing procedure
作者:Eric Block、David Putman
DOI:10.1021/ja00166a073
日期:1990.5
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.
Prepackaged Ramberg–Bäcklund reagents: useful tools for organic synthesis
作者:Eric Block、Hak Rim Jeon、David Putman、Shao-Zhong Zhang
DOI:10.1016/j.tet.2004.06.032
日期:2004.8
synthesis and reactions of several α,β-unsaturated chloromethyl sulfones is presented, for example [(chloromethyl)sulfonyl]-1,3-propadiene (4), [(chloromethyl)sulfonyl]ethene (5), [(dichloromethyl)sulfonyl]ethene (6) and (E,Z)-1,2-bis[(chloromethyl)sulfonyl]ethene (7). These compounds serve as ‘prepackaged’ Ramberg–Bäcklund reagents, which following an appropriate first step, such as Diels–Alder addition