“…In principle this can be accomplished by lithium complexation 20 using Nethoxymethyl-or, as shown here, by N-trityl protection. 21 Several 1-carbon electrophiles such as CO 2 , Eschenmoser's salt, 22 dichloromethane, formic acid, 23 DMF, 24 paraformaldehyde, ethyl chloroformate or methyl cyanoformate 25 were investigated but the most effective electrophile was found to be ethyl formate. The resulting aldehyde 10 26 is relatively unstable on silica gel and was therefore, without further purification, directly submitted to the Leuckart-Wallach reaction 27 with 6. a) ClCPh 3 , Et 3 N, DMF, 95%; b) nBuLi, THF, HCOOEt, 5% citric acid aq soln, 80%.…”