Die Beeinflußbarkeit der syn-Stereoselektivität bei Carben-Additionen an Olefine

The syn-anti ratio of 7-(R-substituted)-norcaranes (I, R = Ph. F, Cl) formed in the cycloaddn. of cyclohexene (II) with PhCH2F, PhCH2Cl, PhCHBrF, PhCHBr2, FCHBr2, ClCHBr2, or CH2Cl and BuLi in various solvents under N was examd. with respect to influences on the stereoselectivity. II concn. was the strongest factor while the nature of org. halide, solvent, and Li halide formed influenced the selectivity also: syn-anti ratios 2.0-40.0 were obtained for (R = Ph) and 1.85-2.46 for I (R = halogen). I (R = Ph) rearranged to 2-benzyl-1-cyclohexene. [on SciFinder (R)]