bases are preferred to organic bases because higher levels of undesired by product lactone are seen with tertiary amine bases common base that can be employed includes alkali or alkaline earth hydroxide dimethylaminopyridine etc the reaction ph must be maintained at 7 11 preferably between 9 10 the preferred temperature range is in the range of 10 u00b0 to 40 u00b0 c and even more preferably between 0 u00b0 to 5 u00b0 c step c final ph of the reaction mixture should be adjusted to 3 4 by addition of acid a wide variety of acid can be used for step c it can be mineral acid such as hydrogen chloride hydrogen bromide hydrogen iodide or p toluenesulfonic acid etc preferred final ph is 3 5 while adjusting the ph and isolating the product the temperature is preferably maintained between 10 u00b0 to 40 u00b0 c and even more preferably 0 u00b0 to 5 u00b0 c as used herein c 1 6 alkyl means a straight or branched saturated carbon chain having from one to six carbon atoms examples include methyl ethyl n propyl isopropyl n butyl t butyl sec butyl isobutyl n pentyl sec pentyl isopentyl and n hexyl alkali metal refers to a metal in group ia of the periodic table preferably lithium sodium and potassium alkaline earth metal refers to a metal in group.