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
Chlorination of Dimethyl Sulfide and Some of Its Derivatives with Sulfuryl Chloride and Thionyl Chloride<sup>1</sup>
作者:William E. Truce、G. H. Birum、E. T. McBee
DOI:10.1021/ja01134a037
日期:1952.7
Pig Slurry Concentration by Vacuum Evaporation: Influence of Previous Mesophilic Anaerobic Digestion Process
作者:August Bonmatí、Xavier Flotats
DOI:10.1080/10473289.2003.10466112
日期:2003.1
Water can be removed from pig slurry by evaporation, through the application of wasted heat from, a power plant or from other processes. Apart from obtaining a concentrate with an obviously higher nutrient concentration than the original slurry, another objective of water removal is to obtain water as condensate, which could be reused. The objective of this work was to study the vacuum evaporation of pig slurry liquid fraction and to evaluate condensate composition as a function of both pH (4, 5, and 6) and pig slurry type (fresh slurry and anaerobically digested slurry). Batch experiments showed that condensate characteristics, total ammonia nitrogen (NH3-N), volatile fatty acids (VFA), and chemical oxygen demand were strongly dependent on initial slurry pH. In addition to producing part of the required thermal energy, previous anaerobic digestion presented several other clear advantages. The consumption of VFA and other volatile organic compounds during anaerobic digestion reduced the volatilization of organic matter in the evaporation treatment and, consequently, provided a higher quality condensate.
Richtzenhain; Alfredsson, Chemische Berichte, 1953, vol. 86, p. 142,145
作者:Richtzenhain、Alfredsson
DOI:——
日期:——
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.