Corrigendum to “A concise synthesis of l-4,4-difluoroglutamine”: [Tetrahedron Lett. 42 (2001) 8625–8627]

✍ Scribed by Patrick Meffre; Rajesh H. Dave; Jacques Leroy; Bernard Badet

• Publisher: Elsevier Science
• Year: 2002
• Tongue: French
• Weight: 47 KB
• Volume: 43
• Category: Article
• ISSN: 0040-4039
• DOI: 10.1016/s0040-4039(02)01321-7

✦ Synopsis

Recently, we were led to re-examine our structural assignments of the final product reported in the above publication: further detailed analyses showed that the product obtained after amino group deprotection was actually L-4,4- difluoroglutamic acid 9 due to concomitant hydrolytic cleavage of the amide group. This problem could be cicumvented by using a different amino protecting group which could be removed under non hydrolytic conditions. Analytical data given in reference 23 on page 8627 correspond indeed to L-4,4-difluoroglutamic acid 9 and are in agreement with the previously described data for the same compound. 1,2 Molecular mass for L-4,4-difluoroglutamic acid 9 is M=183 u versus M=182 u for L-4,4-difluoroglutamine 1. Supplementary MS and microanalysis data are given below. MS (DCI, NH 3 ): m/z 200 (M-H 2 O+NH 3 NH 4 ) + , 183 (M-H 2 O+NH 4 ) + where M=183 u. MS (DCI, ND 3 ): m/z 209 (M%-D 2 O+ND 3 ND 4 ) + , 189 (M%-D 2 O+ND 4 ) + where M%=187 u for deuteriated L-4,4difluoroglutamic acid. MS (ESI, negative mode): m/z 182 (M-H) -.