... Select a Journal or Book ... had the characteristic coupling pattern [ 3 J H−H(cis) = 16.4 Hz, 3 J H−H(trans) = 21.4 Hz, 2 J H−H ... 3−x Al(CH═CH 2 ) x , although they were postulated and generated many times as intermediates in situ for transformations in organic chemistry.(14) It ...