[1]Tetrahedron,2007,vol.63,p.12303-12309
[2]Patent:US6008351,1999,A
[3]Patent:US6011158,2000,A
[4]Patent:US5658930,1997,A
[5]Patent:US6342504,2002,B1.Locationinpatent:Pagecolumn46-47
[6]BioorganicandMedicinalChemistryLetters,2002,vol.12,p.1203-1208
[1]Patent:US6369080,2002,B2.Locationinpatent:Example4
[2]BioorganicandMedicinalChemistryLetters,2003,vol.13,p.723-728