LDA (LITHIUM DIISOPROPYLAMIDE) MEDIATED REACTIONS OF 1-NAPHTHALYNES WITH LITHIATED ACETONITRILES AND 1,4-DIPOLAR NUCLEOPHILIC ANIONS

3-Bromo-2-methoxy-(5) and 3-bromo-2-methoxy-6-methylnaphthalene (6) yi eld 1-naphthalyne intermediates which react with various alpha-lithiat ed nitriles 10 to afford both rearranged 1-arylmethyl- or hetarylmethy l-3-methoxynaphthalene-2-carbonitriles 11 and 12, respectively, and al pha-naphthylated aryl- or hetarylacetonitriles 13 and 14, respectively . Product distributions 11: 13 favoring rearranged nitriles (65: 35-90 : 10) were obtained from LDA-mediated reactions of 5 with arylacetonit riles 9a, b and thiopheneacetonitriles 9c, d. Similar treatment of 6 w ith 9a-d gave product distributions 12: 14 heavily in favor of rearran ged nitriles (> 90: 10) presumably due to the ability of the additiona l 7-methyl group to increase the rate of cyclization of the initial ar yne-nitrile anion adduct, the crucial step in the rearrangement pathwa y. However treatment of either 5 or 6 with a-lithiated pyridylacetonit riles 9e, f or 2-benzimidazolylacetonitrile (9g) gave product distribu tions 11: 13 or 12: 14, respectively, heavily in favor of alpha-naphth ylated acetonitriles (30: 70 < 10: 90). Additionally, several precurso rs to methoxy-substituted 1-naphthalynes 5, 19 and 20 were found to un dergo cycloaddition with the dipolar nucleophilic precursors 3-cyanoph thalide (17) and alpha-cyano-o-tolunitrile (21) to give angularly subs tituted benz[a]anthracene derivatives 18, 22.