Conversion of an epoxide into an alcohol
Superhydride (lithium triethylborohydride) does this. JACS 95 (1973)  8486 reports complete selectivity for unsubstituted over disubstituted carbon with very high yield. HC Brown JOC 45 (1980) (1) reports complete selectivity for 2-butanol from 1,2 epoxybutane and 97:3 for the reduction of styrene oxide.