Download full text in PDF Opens in a new window. Article suggestions will be shown in a dialog on return to ScienceDirect. ... Please enable JavaScript to use all the features on this page. ... Regioselective reactions on the C5-, C7- and C23-hydroxyl groups of the macrocyclic lactones (1), (3) and (4) are described. ... The natural products R 2 = Me, Et, i-Pr can be derivitized regioselectively at C(5) and/or C(7) and/or C(23). ... = 668.8, triclinic, = 11.580 (1), = 14.368(3), = ...