Methylene hydroxycarboxylic acid

This stoichiometric chemistry has been revisited in the last few years [60,79-82] and, for instance, applied to the s)mthesis of a-methylene-y-hydroxy carboxylic acids and their derivatives (c/s-p.y-disubstituted a-methylene-y-lactones) by means of nickel-mediated sequential addition of carbon dioxide and aldehydes into terminal or internal allenes [80, 81], or exploited for the preparation of P-hydroxycarboxylic acid derivatives by 02-oxidation of the Ni-n -allyl species (5.8)... 

Copper quinoline Methylene compds. from /5-hydroxycarboxylic acids... 

A mixture of phenylacetic acid, benzyl alcohol, and tri-n-butylamine in methylene chloride added under argon to a mixture of l-methyl-2-bromopyridinium iodide and methylene chloride, and refluxed 3 hrs. benzyl phenylacetate. Y 97%. F. e., also with l-methyl-2-chloropyridinium iodide, s. T. Mukaiyama et al., Chem. Lett. 1975, 1045 Bull. Chem. Soc. Japan 50, 1863 (1977) carboxylic acid amides from amines (cf. Synth. Meth. 26, 367) s. ibid. 1975, 1163 3,4-dihydro-2H-pyrido-[1,2-a]pyrimid-2-one as acid scavenger cf. ibid. 1976, 13, 57 lactones from hydroxycarboxylic acids (cf. Synth. Meth. 17, 320) with 2-chloropyridine methio-dide and triethylamine s. ibid. 1976, 49 esters with 2 halogeno-3-ethylbenzothia-zolium salts of ibid. 1976, 267 2-chloro-N-methylbenzothiazolium triflate as condensing agent s. F. Souto-Bachiller, G. S. Bates, and S. Masamune, Chem. Com-mun. 1976, 719. 

---