Isopropylidene malonate, 97%, Thermo Scientific Chemicals

General References:

1. Malonate ester which is an unusually strong acid (pK_a 9.97) in comparison with, e.g. Diethyl malonate, A15468 : J. Am. Chem. Soc., 70, 3426 (1948). The mild conditions required for alkylation, acylation, etc. and the ease with which the products undergo alcoholysis or hydrolysis-decarboxylation make Meldrum's acid a valuable and versatile synthetic intermediate. Reviews: Chem. Soc. Rev., 7, 345 (1978); Heterocycles, 32, 529 (1991); Synlett, 1649 (2004).
2. For phase-transfer alkylation using K₂CO₃ as base, see: Synthesis, 452 (1982); Bull. Soc. Chim. Belg., 104, 643 (1995). Phase-transfer addition to Michael acceptors also occurs: Synthesis, 224 (1984). Mitsunobu dialkylation with an alcohol and DIAD/Ph₃P is also possible: J. Org. Chem., 62, 1617 (1997).
3. Knoevenagel condensation with aldehydes gives ylidene derivatives which are solvolyzed by alcohols to give monoesters of alkylidene or arylidene malonic acids: J. Am. Chem. Soc., 74, 5897 (1952). For diastereoselective condensation with citronellal, followed by intramolecular Diels-Alder reaction, see: Org. Synth. Coll., 8, 353 (1993). With formaldehyde in pyridine gives the stable pyridinium methylide which, on treatment with acid, generates the useful reactive Michael acceptor and dienophile, methylene Meldrum's acid: Synthesis, 215 (1996).