Addition of n-Butyllithium to Hydroxybicyclohept-2-enes

Article abstract of DOI:10.1021/jo01313a006

n-Butyllithium adds to the double bonds of bicyclo<2.2.1>hept-2-ene (7), endo-bicyclo<2.2.1>hept-5-en-2-ol (9), exo-bicyclo<2.2.1>hept-5-en-2-ol (12), syn-bicyclo<2.2.1>hept-2-en-7-ol (14), and anti-bicyclo<2.2.1>hept-2-en-7-ol (18).The n-butyl group was shown to be attached at an exo position and in the additions to 9 and 12 to be at C-5 rather than C-6.Competition experiments suggest that addition to 9 is somewhat faster than to 7 but that additions to 14 and 18 are slower.The role of a metalated hydroxyl group in assisting these reactions is considered.No addition products were obtained from reactions at ambient temperature of n-butyllithium with 3-(hydroxymethyl)-1,2-diethylcyclopropene (20), 3-(hydroxymethyl)-1,2-dimethylcyclopropene (23), or 3-(hydroxymethyl)-1-propylcyclopropene (24), but some 1-(hydroxymethyl)-2-ethylidene-3-deuterio-3-ethylcyclopropane (21) was obtained from a reaction with 20 at dry ice temperature followed by quenching with D2O.