磁核共振Assignment-2.pdfVIP

Assignment 2 - Instructions The folder attached to the email contains the raw data from acquisition of a 13C NMR spectrum of sample A. The sample is an ca. 3:1 mixture of two diastereomers with MF C H O . Both 25 48 9 diastereomers are Cs symmetric and each shows 13 signals in the 13C NMR spectrum (12 signals representing a pair of enantiotopic carbons and 1 representing a single carbon) . What you need to do: • process the FID contained in the folder referred to above • in the attached form, using boxes 1-13, list the 13 signals for the major diastereomer according to the instructions below for reporting chemical shift. In the assignment column, indicate with an * that signal that represents a single carbon • in the attached form, in boxes 16-28, list the 13 signals for the minor diastereomer according to the instructions below for reporting chemical shift. In the assignment column, indicate with an * that signal that represents a single carbon Note: Three signals for the minor isomer are hard to find (those @ ca. 114, 77, and 27) because they are close to signals for the major isomer (or solvent). To see those signals you will need to maximize the resolution by using zero filling(increasing digital resolution by increasing SI) and resolution enhancement (processing with Gaussian broadening (GFP) with GB set between 0-1 and LB set between 0 and -1) CH OMe CH OMe 2 2 13C NMR DATA O OH