Benzyl ethers lithium naphthalenide

Alkali metals (such as Li) in liquid ammonia are commonly applied for the deprotection of benzyl (Bn) ethers . Lithium naphthalenide prepared from lithium and naphthalene in stoichiometric amount or catalytic amount is often used to deprotect benzyl ethers. 

A 17-steroidal ketone was deprotonated by LDA to protect it from reduction during a lithium naphthalenide cleavage of a benzyl ether. ... 

Lithium naphthalenide (prepared from lithium and 1.33 equivalents of naphthalene) also reductively cleaves benzyl ethers [Scheme 4.143],262 Some functionalities survive the reaction conditions like carbon-carbon double bonds, benzene rings, THP ethers, stlyl ethers and methoxymethyl ethers. A ketone group can be present but its prior conversion to an enolate is necessary. A similar transformation, but with a catalytic amount of naphthalene, has been reported.263 Although allyl ethers are also cleaved by the procedure, the selective deprotec-... 

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