Stereoselective sulfoxide formation from a thioproline derivative
摘要:
Oxidation of the PEP inhibitor, thioprolylpyrrolidine derivative 3 affords a mixture of the two possible trans- and cis-sulfoxide isomers 4 and 5. 3-Chloroperbenzoic acid oxidation resulted almost exclusive formation of the trans-isomer (a-sulfoxide, 4, d.e. >99% in CHCl3), whereas when NaIO4 was used the cis isomer (beta-sulfoxide, 5) was also obtained, the ratio of the isomers varying with the reaction conditions applied. The structures of the separated isomers 4 and 5 were assigned on the basis of the aromatic solvent-induced shifts (ASIS) in the NMR spectra. (C) 2002 Elsevier Science Ltd. All rights reserved.
Stereoselective sulfoxide formation from a thioproline derivative
摘要:
Oxidation of the PEP inhibitor, thioprolylpyrrolidine derivative 3 affords a mixture of the two possible trans- and cis-sulfoxide isomers 4 and 5. 3-Chloroperbenzoic acid oxidation resulted almost exclusive formation of the trans-isomer (a-sulfoxide, 4, d.e. >99% in CHCl3), whereas when NaIO4 was used the cis isomer (beta-sulfoxide, 5) was also obtained, the ratio of the isomers varying with the reaction conditions applied. The structures of the separated isomers 4 and 5 were assigned on the basis of the aromatic solvent-induced shifts (ASIS) in the NMR spectra. (C) 2002 Elsevier Science Ltd. All rights reserved.