Carbon‐13 resonance assignments of cerin acetate, 2α‐pyridine‐N‐oxyfriedelan‐3‐one, epi‐cerin and its acetate, 3α‐hydroxyfriedelan‐2‐one and its acetate, 3‐hydroxyfriedel‐3‐en‐2‐one and its acetate, friedelane‐3,7‐dione, 3β‐hydroxyfriedelan‐7‐one, canophyllol, friedelolactone and friedelolactone‐2α‐yl acetate, friedelane‐2α,3β‐diol and its diacetate, friedelane‐2β,3α‐diyl diacetate, pachysandiyl‐A diacetate and friedelane‐2β‐3β‐diyl diacetate have been made. The carbon signals of 3‐oxofriedelan‐29‐ol and its acetate, methyl 3‐oxofriedelan‐29‐oate, 3‐oxofriedelan‐30‐ol, maytenfoliol, maytensifolin‐A, maytensifolin‐B, pachysonol and pristimerin reported in the literature have also been considered for their specific resonance assignments. A few signal assignments of some friedelanes, viz. friedelan‐28‐ol, friedelan‐29‐ol, friedelan‐30‐ol, friedelan‐29‐al, 3‐oxofriedelane‐21α,26‐diol and zeylasterone, reported recently by others, are unusual and have been reviewed. Copyright © 1987 John Wiley & Sons Ltd.