Convenient Synthesis of .ALPHA.-Trifluoromethylated Acyloins from .ALPHA.-Hydroxy or .ALPHA.-Amino Acids.
作者:Masami KAWASE、Setsuo SAITO、Teruo KURIHARA
DOI:10.1248/cpb.48.1338
日期:——
acyloins (2 and 6) have been prepared from alpha-hydroxy acids (1), N-acylprolines (5) or N-acyl-N-alkyl alpha-amino acids (8) by novel transformation reactions with trifluoroacetic anhydride (TFAA) in the presence of pyridine. The former reaction of 1 could proceed through mesoionic 1,3-dioxolium-4-olates, whereas the latter two reactions of alpha-amino acids (5 and 8) could involve mesoionic 1,3-oxazolium-5-olates
α-三氟甲基化酰基辅酶(2和6)是由α-羟基酸(1),N-酰基脯氨酸(5)或N-酰基-N-烷基α-氨基酸(8)与三氟乙酸酐( TFAA)在吡啶存在下。前者1的反应可以通过1,3-二氧恶唑鎓4-olates进行,而后两个α-氨基酸(5和8)的反应可能涉及1,3-二恶唑鎓5-olates。1与TFAA的反应在实际应用中显示出更大的潜力,这是因为起始材料易于使用且易于操作。