Triethylmethylammonium dimethyl phosphate

In a synthesis of A -cholestadiene-la,3 -diol (la-hydroxyprovitamin D3), Israeli chemists effected dehydrobromination of the dibromide (1) at 130° (4 hr.) in HMPT containing about 10% of triethylmethylammonium dimethyl phosphate. A 1.3 1 mixture of the A -diene (2) and the A -diene (3) was obtained in almost quantitative yield. The mixture was separated on a silica column impregnated with silver nitrate. 

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