Substance
ID:717858
Names and Identifiers
IUPAC name
2,2-dimethyl-1,3-dioxane-4,6-dione
IUPAC Traditional name
meldrum's acid
Synonyms
2,2-Dimethyl-1,3-dioxane-4,6-dioneMeldrum's Acid丙二酸亚异丙酯Isopropylidene malonate
Registration numbers
CAS Number
EC Number
MDL Number
Beilstein Number
Merck Index
Properties
Physical Property
Melting Point
92-96°C
Safety Information
Risk Statements
36/37/38
Safety Statements
26-37
GHS Pictograms
Acute toxicity (oral, dermal, inhalation), category 4
Skin irritation, category 2
Eye irritation, category 2
Skin sensitisation, category 1
Specific Target Organ Toxicity – Single exposure, category 3
GHS Precautionary statements
P261-P305+P351+P338-P302+P352-P321-P405-P501A
European Hazard Symbols
Irritant (Xi)GHS Hazard statements
H315-H319-H335
TSCA Listed
是
RTECS
JH0800000
Product Information
Purity
98%
Molecule Details
No Data Available
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Molecular Spectra
No Data Available
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References
• See also: Org. Synth., 77, 114 (1999).
• C-Acylation with acyl chlorides occurs in the presence of 2 equivalents of pyridine in high yield. Alcoholysis of the product provides a good route to ?-keto esters: J. Org. Chem., 43, 2087 (1978); Org. Synth. Coll.,7, 359 (1988), also obtainable by reaction of the Na salt with acid anhydrides in DMF: Synthesis, 451 (1982). Alternatively, mild hydrolysis and decarboxylation of the intermediate acyl Meldrum's acid gives the methyl ketone, providing an alternative to organometallic methods for conversion of acyl chlorides to methyl ketones: Synth. Commun., 10, 221 (1980):
• Malonate ester which is an unusually strong acid (pKa = 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).
• 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).
• With an aryl aldehyde in the presence of triethylamine and formic acid at ambient temperature, in situ reduction to the arylmethyl Meldrum's acid occurs, whereas at 70-80oC, the 3-arylpropionic acid is obtained: Synth. Commun., 25, 3067 (1995).
• 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).
• Condensation with lactim ethers, catalyzed by Nickel(II) 2,4-pentanedionate, 18811, with alcoholysis of the resulting enamino Meldrum's acids, gives of cyclic ?-enamino esters, useful as alkaloid precursors: J. Org. Chem., 43, 4662 (1978); for an example, see: Org. Synth. Coll., 8, 263 (1993).