Tetralins 1,2-disubstituted

The preference of 2,7-disubstituted oxepins for this tautomeric form at equilibrium may be rationalized in terms of a steric substituent effect. The eclipsing interactions of the 2,7-substituents in the arene oxide form will be diminished by isomerization to the oxepin. When the 2,7-substituents form part of an annelated ring system, e.g. (22)-(24), the tautomeric preference will be determined by the size of the methylene bridge (67AG(E)385). Thus when n = 5 the annelated oxepin (24) was present in approximately equal proportions with the arene oxide form. However with n =4. (23) tetralin 9,10-oxide was dominant. The... 

In the dihydronaphthalene series, the selective exo addition of the nucleophile and exo addition of the electrophile (steric approach) results in exclusive formation of the c/r-ot,3-disubstituted tetralin (78 equation 53).128... 

The calamenene skeleton contains only two asymmetric carbon atoms 1,4-disposed on a tetralin system. Until recently, the synthesis of this skeleton had only been achieved starting from chiral pool agents with the two asymmetric carbon atoms of interest of predetermined configuration (71,72). Recent developments in synthetic methodology now allow the elaboration of the 1,4-P-aiw-or 1,4-ci j- disubstituted system starting from 5-methoxytetralone or its equivalent (73-75). 

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