An alkali metal hybride(NaH) reacts with diborane in ‘A’ to give a tetrahedral compound ‘B’ which is extensively used as reducing agent in organic synthesis. The compounds ‘A’ and ‘B’ respectively are
(C2H5)2O and NaBH4
2NaH+B2H6(C2H5)2O−−−−−−→2NaBH4