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Thioalkylation of Meldrum 's Acid: Protected alkylidene derivatives of isopropylidene malonate
Author(s) -
Eberle Martin,
Lawton Richard G.
Publication year - 1988
Publication title -
helvetica chimica acta
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.74
H-Index - 82
eISSN - 1522-2675
pISSN - 0018-019X
DOI - 10.1002/hlca.19880710816
Subject(s) - chemistry , thiophenol , adduct , malonate , hexamethylenetetramine , organic chemistry , nucleophile , formaldehyde , aldehyde , medicinal chemistry , catalysis
Thioalkylated Meldrum 's acid is easily by treatment of Meldrum 's acid with an aldehyde and thiophenol in the presence of catalytical amounts of piperidinium acetate (→ 1–6 , Table 1 ). The adducts 1–6 are crystalline, stable compounds and they can be caused to react directly with nucleophiles and dienes (see 3→7–12 , Scheme 1 ). The regeneration of the parent olefin is effected thereby by simply dissolving the adduct under neutral or basic conditions. Extension of this method to thiocarboxylic acids allowed the preparation of the corresponding formaldehyde derivatives 13 and 15 (Table 3 ).