3-(Hydroxymethyl)-4, 4-dimethylpentanoic acid?-lactone can be prepared in 62% overall yield in four steps from ethyl 3-hydroxy-3, 4, 4-trirnethylpentanoate. The latter was dehydrated to give a mixture of alp-and 0,~-unsaturated esters which upon bromination with NBS yielded ethyl (Z)-3-(bromomethyl)-4, 4-dimethyl-2-penten-oate. Thermal cyclization of the bromo ester produced 3-tert-butyl-2-buten-1, 4-olide, which was hydrogenated to give ...
