A method for making a compound of formula comprising (a) converting a compound of formula to a compound of formula and (b) contacting the compound of formula with a transition metal catalyst to provide the compound of formula; wherein: the compound of formula is a compound of formula wherein: R 14 and R 16 are each independently selected from -OH, -H, and -OR 17; R 17 is an oxygen protecting group; and R 15 is selected from -OH, -H, -OR 17, =O, and =CH 2; R 4 is selected from the group consisting of -H, -(C 1 -C 6) alkyl, phenyl, allyl, -2-butenyl, -3-butenyl, -4-pentenyl, -2-propynyl, -2-butynyl, -3-butynyl, -2-pentynyl, R 5, R 6, and R 7 are each independently selected from -H, -(C 1 -C 6) alkyl, -(C 2 -C 6) alkenyl, and -(C 2 -C 6) alkynyl, each alkyl, alkenyl, and alkynyl being unsubstituted or substituted with 1, 2, 3, 4, or 5 independently-selected R 8 groups, or R 6 and R 7 are taken together with the carbon atoms to which each is bound to form a carbocyclic ring of 3, 4, 5, 6, 7, 8, or 9 carbon atoms, the carbocyclic ring being unsubstituted or substituted with 1, 2, 3, 4, or 5 independently-selected R 8 groups; each R 8 is independently selected from -OR 51, -F, -Cl, -Br, -I, phenyl, and -(C 1 -C 6) alkyl; and each R 51 is independently selected from-(C 1 -C 6) alkyl and an oxygen protecting group. (a) converting a compound of formula to a compound of formula and (b) contacting the compound of formula with a transition metal catalyst to provide the compound of formula; the compound of formula is a compound of formula wherein: R 14 and R 16 are each independently selected from -OH, -H, and -OR 17; R 17 is an oxygen protecting group; and R 15 is selected from -OH, -H, -OR 17, =O, and =CH 2; R 4 is selected from the group consisting of -H, -(C 1 -C 6) alkyl, phenyl, allyl, -2-butenyl, -3-butenyl, -4-pentenyl, -2-propynyl, -2-butynyl, -3-butynyl, -2-pentynyl, R 5, R 6, and R 7 are each independently selected from -H, -(C 1 -C 6) alkyl, -(C 2 -C 6) alkenyl, and -(C 2 -C 6) alkynyl, each alkyl, alkenyl, and alkynyl being unsubstituted or substituted with 1, 2, 3, 4, or 5 independently-selected R 8 groups, or R 6 and R 7 are taken together with the carbon atoms to which each is bound to form a carbocyclic ring of 3, 4, 5, 6, 7, 8, or 9 carbon atoms, the carbocyclic ring being unsubstituted or substituted with 1, 2, 3, 4, or 5 independently-selected R 8 groups; each R 8 is independently selected from -OR 51, -F, -Cl, -Br, -I, phenyl, and -(C 1 -C 6) alkyl; and each R 51 is independently selected from-(C 1 -C 6) alkyl and an oxygen protecting group. R 14 and R 16 are each independently selected from -OH, -H, and -OR 17; R 17 is an oxygen protecting group; and R 15 is selected from -OH, -H, -OR 17, =O, and =CH 2; R 4 is selected from the group consisting of -H, -(C 1 -C 6) alkyl, phenyl, allyl, -2-butenyl, -3-butenyl, -4-pentenyl, -2-propynyl, -2-butynyl, -3-butynyl, -2-pentynyl, R 5, R 6, and R 7 are each independently selected from -H, -(C 1 -C 6) alkyl, -(C 2 -C 6) alkenyl, and -(C 2 -C 6) alkynyl, each alkyl, alkenyl, and alkynyl being unsubstituted or substituted with 1, 2, 3, 4, or 5 independently-selected R 8 groups, or R 6 and R 7 are taken together with the carbon atoms to which each is bound to form a carbocyclic ring of 3, 4, 5, 6, 7, 8, or 9 carbon atoms, the carbocyclic ring being unsubstituted or substituted with 1, 2, 3, 4, or 5 independently-selected R 8 groups; each R 8 is independently selected from -OR 51, -F, -Cl, -Br, -I, phenyl, and -(C 1 -C 6) alkyl; and each R 51 is independently selected from-(C 1 -C 6) alkyl and an oxygen protecting group.