Sample Description:

Molecular Formula: C5H10O Molecular Weight: 86.132 InChI= 1/C5H10O/c1-3-5(6)4-2/h3-4H2,1-2H3 IUPAC Name:  Pentan-3-one CAS Number: 96-22-0 PubChem: 7288 NMRShiftDB: 10008778 Spectrometer: 300 MHz Solvent: CDCl3 Provided by:  FTNMR FID Archive - Pacific Lutheran University

*.fid	np	nt	sw	rfp-rfl	ni	sw1	rfp1-rfl1	time
proton	8192	8	6024.11	-1664.802				?
carbon	8192	552	20000.00	-2106.735				?

1D Proton Spectrum:

1D Carbon Spectrum (Deuterated Solvent Resonances Subtracted):

Automated VerifyIt Proton Assignments:

Automated VerifyIt Carbon Assignments:

Top 10 FindIt Molecular Structures Consistent With Molecular Formula and Proton Resonances:

The correct structure is at position 2.

 Best 10 structures in decreasing rating (structure ID shown in parentheses):
    1: 0.977558 (  102618)    2: 0.977070 (    7288)    3: 0.962248 ( 5463824)
    4: 0.960437 (    7895)    5: 0.960140 (  121763)    6: 0.958853 (  520554)
    7: 0.956336 (   11251)    8: 0.954491 ( 6440261)    9: 0.929513 (   22615)
   10: 0.927688 (   21158)
			

Top 10 FindIt Molecular Structures Consistent With Proton and Carbon Resonances:

The correct structure is at position 1.

 Best 10 structures in decreasing rating (structure ID shown in parentheses):
    1: 0.966454 (    7288)    2: 0.950403 (10130096)    3: 0.897061 (10899304)
    4: 0.895475 (  417974)    5: 0.895386 (  569147)    6: 0.887782 (10943591)
    7: 0.883178 (10130095)    8: 0.875051 ( 3034073)    9: 0.863612 (   16841)
   10: 0.858024 (   62539)
			

Comments:

The top FindIt structure for proton and carbon results is the correct one. For molecular formula and proton results, FindIt only obtains place two, though the molecular assignments are in NMRShiftDB. The challenge results from two "egonw" assigned proton spectra. Spectrum 31273 contains Aldrich Library of NMR Spectra shifts and agrees with this proton spectrum. But proton spectrum 20099201 specifies both methyl group shifts at 1.23 ppm, about 0.2 ppm higher than the first spectrum and our proton spectrum analysis results. NMRShiftDB specifies additional information is available from http://chipo.chem.uic.edu/web1/ocol/spec/H_NMR2.htm. "ping chipo.chem.uic.edu" succeeds, but the specified link location no longer seems to exist. If no explanation can be found, this questionable "spectrum" might be removed from NMRanalyst's shift prediction.