BuLi

Note I. A solution of 1-1ithiomethoxyal1ene, prepared from methoxyallene and BuLi-hexane-THF, did not react with ethylene oxide below 20°C. The reaction started at about 30°C, but the reaction mixture became very dark. 

Note 1. If commercial BuLi in hexane is used with diethyl ether or THF as cosolvent, a dark brown reaction mixture is formed, from which the desired product can be isolated in lower yields. 

KO-iert.-C iHg-DHSO, BuLi in diethyl ether or THF and lithium dialkylaraide-43... 

Note 1. Prepared by lithiating HC CCH2C1 at -80°Cwith BuLi in hexane-ether (1 1) and subsequently adding freshly distilled acetaldehyde (compare Ref. 1). 

Dioxo compounds are deprotonated at C-2 and C-4 by two equivalents of strong bases (e.g. LDA or BuLi). Carbon atom C-4 of those dianions is much more nucleophilic than the less basic center C-2 (Hauser s rule C.R. Hauser, 1958 K.G. Hampton, 1965). The formation of some typical d -synthons and their pA values are given below. 

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