A new synthesis of unsymmetrical phosphinic acids R′P(O)OHR″ has been evaluated. The first P–C bond was formed by base‐promoted H‐phosphinate alkylation of a protected H‐phosphinate, which is easier and safer to handle. A one‐pot methodology was developed for the second P–C bond formation reaction that involves the sila‐Arbuzov reaction. This methodology was then extended to the synthesis of a dialkylphosphinic acid with an amino functionality. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009)

The title compound, C8H11O2P, is a phosphinic compound with a tetra­coordinate penta­valent P atom. The phosphinic function plays a predominant role in the cohesion of the crystal structure, both by forming chains along the b axis via strong inter­molecular O—H⋯O hydrogen bonds and by cross-linking these chains perpendicularly via weak inter­molecular C—H⋯O hydrogen bonds, generating a two-dimensional network parallel to (001).