ASYMMETRIC SYNTHESIS OF SULTAMS AND SULFONAMIDES VIA DIASTEREOSELECTIVE REDUCTION OF N-SULFONYLIMINES
作者:Franklin A. Davis、Ping Zhou、Bang-Chi Chen
DOI:10.1080/10426509608037955
日期:1996.8.1
The diastereoselective reduction of both cyclic and acyclic camphor sulfonylimines was investigated. With cyclic camphor sulfonylimines 1, reduction using NaBH4 in methanol afforded the corresponding camphorsultarns 2 in 92-95% yield as single diastereomers with the exception of Ic where debromination occurred prior to reduction. For the large scale preparation of camphorsultam la and its derivatives, important chiral auxiliaries in asymmetric synthesis, reduction with NaBH4 is the reagent of choice. Reduction of acyclic camphor sulfonylimines 7 to camphorsulfonamides 8 with the bulky reducing reagent, LiAl(OBu-i)(3)H afforded the highest de's (>90% de) and yields 90-95%.
Karrer, Friedrich; Kayser, Hartmut; Buser, Hans Peter, Chimia, 1993, vol. 47, # 7-8, p. 302 - 306
作者:Karrer, Friedrich、Kayser, Hartmut、Buser, Hans Peter、Tombo, Gerardo M. Ramos
DOI:——
日期:——
Efficient Enantioselective Synthesis of (<i>R</i>)-(−)-Carnitine from Glycerol
作者:Mauro Marzi、Patrizia Minetti、Giampiero Moretti、Maria Ornella Tinti、Francesco De Angelis