catalyst, 5, 6 under condltlons of continuous removal of the methanol-toluene azeotrope. Dlstlllation gave (in 50% yield from acroleln) methyl 4-nonen-6-ynoate (! a), bp 130"(20 mm) Glc analysis of the product showed it to contain an E 2 ratio of ca. 4.1 (cf ref 6)---- The pure E isomer can be readily obtained by distillation of the isomer mixture on a spinning-band column, but such a separation 1s unnecessary at this stage