# Can NaH open the epoxide ring to form alcohol? If so, how?

I was looking at the organic chemistry 8th Ed textbook by Paula Yurknais Brucie. On page 509, I found this:

I think about it for a while and I am doubting that it is wrong. I believe the hydride ion itself cannot act as a nucleophile for SN2. (not really sure but I guess it is too small and too basic to work as a nucleophile, it should be much easier to attack hydrogen rather than carbon for hydride ion)

Is this reaction is possible with $$\ce{NaH}$$ in solvents other than water and alcohol? If so, how does the hydride ion open the epoxide ring? (hoping for an answer with mechanism)

And I am specifically talking about hydride ion (or hydrogen anion). Not sodium borohydride $$\ce{NaBH4}$$, lithium aluminum hydride $$\ce{LiAlH4}$$, or other metal hydrides.

• Well, there's no proton acidic enough, so it's gonna open the ring. Aug 21 '21 at 18:14
• Going to have to be in aprotic solvent. NaH reacts vigourously with alcohols and water Aug 21 '21 at 20:00
• I have been looking for this reaction and I find no examples. Nor in my limited experience of 40+ years can I ever recall seeing sodium hydride used as a source of nucleophilic hydride without some modifying agent (such as this example sciencedirect.com/science/article/abs/pii/S0040403900986313). Perhaps someone who has better database access than I can find it. Aug 21 '21 at 20:47
• @Mithoron I don't think so. It is going to sit there and do nothing until it is worked up. Aug 22 '21 at 19:12
• @MathewMahindaratne the answer you refer to concerns LiAlH4 opening of epoxides. It specifically excludes any reference to NaH even though the OP asked about NaH. Sep 1 '21 at 10:24

Further to my comments above, I am going to offer my opinion that the book is wrong and the epoxide is not opened by sodium hydride as depicted. I have failed to find any literature examples of such a reaction and, in 40+ years as a synthetic chemist, I can recall no reactions in which $$\ce{NaH}$$, unmodified by other reagents, acts as a source of nucleophilic $$\ce{H-}$$.