摘要 |
<p>PT--81818 A 5-(Z)-7-(4,5-cis 2,2-dimethyl 4-phenyl 1,3-dioxan-5-yl heptenoic acid is made by (a) redn. of ethyl 2-benzoyl 4-chloro butanoate with a metal hydride to obtain a 1,3-diol; (b) conversion to a 1,3-dioxane by treatment with acetone, by heating in presence of a dehydrating agent to give 5-(2-chloro ethyl) 2,2-dimethyl 4-phenyl 1,3-dioxan; (c) treatment with triphenyl phosphine in a suitable solvent to give the corresp. triphenyl phosphorane; (d) reacting this with 4-chloro butyraldehyde in a Wittig reaction; and (e) treatment of the halogenated prod. with cyanide and basic hydrolysis of the nitrile formed.</p> |