A method for N-demethylating a compound of formula comprising (a) contacting the compound of formula with a compound of formula in a solvent to provide a compound of formula and (b) converting the compound of formula to a compound of formula wherein the solvent comprises from 80 vol% up to 100 vol% or consists of a tertiary alcohol selected from the group consisting of tert -amyl alcohol, tert- butyl alcohol, 3-methyl-3-pentanol, 2,3-dimethyl-3-pentanol, 3-ethyl-3-pentanol, 2-methyl-2-hexanol, and mixtures of two or more thereof; the ------ 7,8-bond is a single bond or a double bond; R 9 and R 11 are each independently selected from the group consisting of -OH, -H, and -OR 15; R 9' and R 11' are each independently selected from the group consisting of -OH, -H, -OR 15, and -OC OR 4; R 10 is selected from the group consisting of =O, -OH, =CH 2, -H, and -OR 15; R 10' is selected from the group consisting of =O, -OH, =CH 2, -H, -OR 15, and -OC OR 4; R 15 is an oxygen protecting group; R 4 is selected from the group consisting of -(C 1 -C 6)alkyl, -(C 2 -C 6)alkenyl, -(C 2 -C 6)alkynyl, aryl, and heteroaryl, each being unsubstituted or substituted with 1, 2, 3, 4, or 5 independently-selected R 5 groups; each R 5 is independently selected from the group consisting of -OH, -Cl, Br, -I, -NH 2, -CN, -O-(C 1 -C 6) alkyl, and phenyl; and X is selected from the group consisting of -Cl, -Br, -I, mesylate, and tosylate. (a) contacting the compound of formula with a compound of formula in a solvent to provide a compound of formula and (b) converting the compound of formula to a compound of formula wherein the solvent comprises from 80 vol% up to 100 vol% or consists of a tertiary alcohol selected from the group consisting of tert -amyl alcohol, tert- butyl alcohol, 3-methyl-3-pentanol, 2,3-dimethyl-3-pentanol, 3-ethyl-3-pentanol, 2-methyl-2-hexanol, and mixtures of two or more thereof; the ------ 7,8-bond is a single bond or a double bond; R 9 and R 11 are each independently selected from the group consisting of -OH, -H, and -OR 15; R 9' and R 11' are each independently selected from the group consisting of -OH, -H, -OR 15, and -OC OR 4; R 10 is selected from the group consisting of =O, -OH, =CH 2, -H, and -OR 15; R 10' is selected from the group consisting of =O, -OH, =CH 2, -H, -OR 15, and -OC OR 4; R 15 is an oxygen protecting group; R 4 is selected from the group consisting of -(C 1 -C 6)alkyl, -(C 2 -C 6)alkenyl, -(C 2 -C 6)alkynyl, aryl, and heteroaryl, each being unsubstituted or substituted with 1, 2, 3, 4, or 5 independently-selected R 5 groups; each R 5 is independently selected from the group consisting of -OH, -Cl, Br, -I, -NH 2, -CN, -O-(C 1 -C 6) alkyl, and phenyl; and X is selected from the group consisting of -Cl, -Br, -I, mesylate, and tosylate. the solvent comprises from 80 vol% up to 100 vol% or consists of a tertiary alcohol selected from the group consisting of tert -amyl alcohol, tert- butyl alcohol, 3-methyl-3-pentanol, 2,3-dimethyl-3-pentanol, 3-ethyl-3-pentanol, 2-methyl-2-hexanol, and mixtures of two or more thereof; the ------ 7,8-bond is a single bond or a double bond; R 9 and R 11 are each independently selected from the group consisting of -OH, -H, and -OR 15; R 9' and R 11' are each independently selected from the group consisting of -OH, -H, -OR 15, and -OC OR 4; R 10 is selected from the group consisting of =O, -OH, =CH 2, -H, and -OR 15; R 10' is selected from the group consisting of =O, -OH, =CH 2, -H, -OR 15, and -OC OR 4; R 15 is an oxygen protecting group; R 4 is selected from the group consisting of -(C 1 -C 6)alkyl, -(C 2 -C 6)alkenyl, -(C 2 -C 6)alkynyl, aryl, and heteroaryl, each being unsubstituted or substituted with 1, 2, 3, 4, or 5 independently-selected R 5 groups; each R 5 is independently selected from the group consisting of -OH, -Cl, Br, -I, -NH 2, -CN, -O-(C 1 -C 6) alkyl, and phenyl; and X is selected from the group consisting of -Cl, -Br, -I, mesylate, and tosylate.