Doubly Deprotonated Methyl 3‐Mitropropanoate, an Acrylic Ester d2‐reagent

Methyl 3‐nitropropanoate can be doubly deprotonated with LDA, both in the α‐nitro and in the α‐carbonyl position (→ 1). It is shown that the necessary cosolvent HMPT can be replaced by the cyclic urea DMPU, with almost equal results. The new reagent 1 is alkylated and hydroxyalkylated by alkyl halides and aldehydes, respectively, at the 2‐position exclusively (see 2, 4, 6, 7). A double alkylation to methyl α,α‐dialkyl‐β‐nitropropanoate 5 is possible. Elimination of HNO2 with DBN or even better with DBU in THF furnishes methyl α‐methylenealkanoates 9 and methyl β‐hydroxy‐α‐methylenealkanoates 10.