Errata In issue 6 of volume 2 (1985) some of the formulae in the article by D. M. Harrison were incomplete. Structure (121) on page 541 should have been (121) a;R'= RZ= ti ~3= OH b;R'=H,R2=R3=OH C;R'=Rs=OH,Rz=H d;R'= R3= H,R2= OH On page 542 the diagrams in Scheme 14 should have been (122b) (122a)