Shoolery's rule

Shoolery's rule, which is named after James Nelson Shoolery, is a good approximation of the chemical shift δ of methylene groups in proton nuclear magnetic resonance. We can calculate shift of the CH₂ protons in a A–CH₂–B structure using the formula

\delta =0.23\,\mathrm {ppm} +S_{\mathrm {A} }+S_{\mathrm {B} }

where 0.23 ppm is the chemical shift of methane and the empirical adjustments S are based on the identities of the A and B groups:

Substituent	S / ppm
–CH₃	0.47
–COOR	1.55
–COR	1.70
–C₆H₅	1.83
–SR	1.64
–I	1.82
–Br	2.33
–OR	2.36
–Cl	2.53
–OH	2.56
–OCOR	3.13

External links

Organic Spectroscopy: Principles and Applications, page 206

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