GB985731A - Improvements in or relating to new ª‡-carboxylated lactones and their preparation - Google Patents

Abstract

The invention comprises g - and d -lactones of formula <FORM:0985731/C2/1> where n is 1 or 2 and R is alkyl or alkenyl having from (5-n) to (11-n) carbon atoms. They may be prepared by condensing in the presence of an alkaline condensing agent a C1- 2-alkyl carbonate with a lactone of formula <FORM:0985731/C2/2> to form an #c-carb (C1- 2-alkoxy)-lactone, subjecting the latter to an alkaline saponification and acidifying the resulting salt to liberate and lactonise the corresponding hydroxydicarboxylic acid. Alternatively, products in which n=1 (g -lactones) may be prepared by condensing an epoxide of formula <FORM:0985731/C2/3> wherein R is C4- 10 alkyl or alkenyl with an alkali metal salt of a die-(C1- 2-alkyl malonate to give an #c-carb (C1- 2 alkoxy)-g -lactone and converting this to the desired lactone as before. Examples describe the preparation of g -lactones of formula I in which R is C5-, C6-, C7-, C8- and C9-n-alkyl, 1,3,3-trimethylbutyl and 2-methyl-propyl and of d -lactones in which R is C5- and C6-n-alkyl and trans-3-pentenyl. The ethyl esters of each of these is first obtained as an intermediate. g -Nonalactone is obtained as a by-product in the saponification and lactonization of g -carbethoxy-g -nonalactone (Example 11).ALSO:Butter substitutes, e.g. margarine, contain as flavouring at least one lactone of formula: <FORM:0985731/A1-A3/1> where n is 1 or 2 and R is alkyl or alkenyl having from (5-n) to (11-n) carbon atoms (for preparation see Division C2). Conventional butter-flavourings may also be present.