References
- Johnson , W. S. , Belew , J. S. , Chinn , L. J. and Hunt , R. H. 1953 . J. Am. Chem. Soc. , 75 : 4995
- Tung , C. C. , Speziale , A. J. and Frazier , H. W. 1963 . J. Org. Chem. , 28 : 1514 The ratio of isomers was determined by capillary GC analysis of the unfractionated reaction product on a 30 m DB-5 column (25 psi, 200[ddot]C). These isomers were inseparable by either flash or MPLC liquid chromatography. The 300 MHz 1H NMR spectrum of this epoxide mixture displayed Ja,b = 1.8 Hz for epoxide ring protons of the major stereoisomer and Ja,b = 4.6 Hz for the minor isomer. These values are consistent with assignment of trans (major) and cis (minor):
- The pure trans-t-butyl ester was separated by flash chromatography and displayed spectral data consistent with the assigned structure.
- Dagli , D. J. , Yu , P.-S. and Wemple , J. 1975 . J. Org. Chem. , 40 : 3173
- Evans , D. A. , Nelson , J. V. , Vogel , E. and Taber , T. R. 1981 . J. Am. Chem. Soc. , 103 : 3100
- Abdel-Magid , A. , Pridgen , L. N. , Eggleston , D. S. and Lantos , I. 1986 . J. Am. Chem. Soc. , 108 : 4595 The preparation of cis-disubstituted glycidic esters via a multistep sequence involving boron mediated aldol reactions of α-halogenated imide enolates has been reported:
- Oka. , Y. , Motohashi , M. , Sugihara , H. , Miyashita , O. , Itoh , K. , Nishikawa , M. and Yurugi , S. 1977 . Chem. Pharm. Bull. , 25 : 632
- Still , W. C. , Kahn , M. and Mitra , A. 1978 . J. Org. Chem. , 43 : 2923