Synthesis ofN-benzyloxycarbonyl-N-methylaminoacids from oxazolidine-5-one derivatives

✍ Scribed by G. I. Chipens; V. A. Slavinskaya; D. É. Sile; É. Kh. Korchagova; M. Yu. Katkevich; V. D. Grigor'eva

• Publisher: Springer US
• Year: 1992
• Tongue: English
• Weight: 218 KB
• Volume: 28
• Category: Article
• ISSN: 0009-3122
• DOI: 10.1007/bf00475261

✦ Synopsis

compounds. The SSCC agrees well with the dihedral angle found from the Williamson--Johnson curve [6]. The dihedral angles for compounds of the Aa and Ab series that were found in this manner suggest that the angle 4-H--C(4)--C(s)--5-H of Aa is about two times less than the analogous angle of Ab. This is consistent with a large distortion of the oxazolidine ring of Ab compared with Aa. The single exception is 9, which has the bulkiest aromatic substituent on C(2 ). It was found that 3J(4,5 ) of 9Aa (4.18 Hz) is almost two times less than that of 9Ab (8.22 Hz). Apparently steric interactions of the substituent on C(2 ) in 9Aa with the 4-CH 3 and 5-Ph groups significantly distort the ring (angle 4-I-I--C(4)--C(5)--5-t-I is -50 +_ 3~ However, the same interactions of the substituent in the 2-position of 9Ab with the N--Me group flatten the five-membered ring (angle 4-H--C(4)--C(5)--5-H is -30 + 3~ With respect to the Ba--Bb series, the comparative conformations of these isomers cannot be judged from the PMR spectra owing to a lack of data for the Bb isomer.

LITERATURE CITED

, 2. 3. 4. 5. 6.