13C chemical shifts of 1-substituted camphenes

Abstract

¹³ C Chemical shifts of a series of 1-substituted camphenes (1)–(10) are reported. Whereas low-field β-shifts for C(6) and C(7) exhibit normal behaviour for secondary carbons in bridgehead substituted fused ring systems, more strongly electron-withdrawing substituents bring about greater upfield shifts for the sp² hybridised β-C(2). In the 1-hydroxymethyl derivative (6) the presence of intramolecular hydrogen bonding does not bring about a low field shift for C(2).