Propose a reasonable structure for each of the following molecules on the basis of the given molecular formula and of the 1H and proton-decoupled l3C NMR data
(a) C7H16O, spectra J and K (* = CH2 by DEPT);
(b) C7H16O, spectra L and M (the assignments in M were made by DEPT).

H NMR 3 H C NMR 8 H 2 H (CH3)4 Si 2 H l H 5 3.0 2.52.0 5 10 0.5 0.0 300-MHz 1H NMR spectrumn ppm () 60 40 20 "C NMR spectrum ppm () H NMR C NMR 4 H CH CH 6 H CH 2 H 4 H CH34 Si qua 3.5 32.5 25.5 300.MHz iH NMRspectrum ppm