Investigation of diene condensation of primary vinylacetylene and allylacetylene alcohols and their ethers and esters with polychlorocyclic dienes

Synthesis of oxa-bridged derivatives from Diels–Alder bis-adducts of butadiene and 1,2,3,4-tetrahalo-5,5-dimethoxycyclopentadiene

“…The appearance of H 5 at ~3 ppm with characteristic coupling constants of ~9 and ~4 Hz to H 6 and H 6’ , respectively, unequivocally supports the assigned structures. These values are consistent with several endo -substituted derivatives (R = alkyl-like groups) reported by us [ 9 ] and others [ 21 – 22 ]. The observed selectivity is in agreement with the strong endo -selectivity displayed by diene 1 .…”