A method for preparing a compound of formula the method comprising, contacting a compound of formula with a boron based reducing agent, and a carbonyl compound having formula: wherein the contacting is conducted in a solvent and an acid; and wherein at each occurrence, --- is a single bond; L is absent; n is 1; R 1 is H, C 1 -C 6 alkyl, C 1 -C 6 alkoxy, OH, or -O-Pro; R 2 is H, C 1 -C 6 alkyl, C 1 -C 6 alkoxy, OH, or -O-Pro; R 3 is H, C 1 -C 6 alkyl, C 1 -C 6 alkoxy, OH, or -O-Pro, wherein Pro, at each occurrence, is independently a hydroxyl protecting group; R 10 is C 1 -C 6 alkyl, C 2 -C 6 alkenyl, C 2 -C 6 alkynyl, C 3 -C 8 cycloalkyl, -C 1 -C 6 alkyl-aryl, -C 2 -C 6 alkenyl-aryl, -C 2 -C 6 alkynyl-aryl, -C 1 -C 6 alkyl-heteroaryl, -C 2 -C 6 alkenyl-heteroaryl, -C 2 -C 6 alkynyl-heteroaryl, -C 1 -C 6 alkyl- heterocycloalkyl, -C 2 -C 6 alkenyl-heterocycloalkyl, -C 2 -C 6 alkynyl-heterocycloalkyl, -C 1 -C 6 alkyl-C 3 -C 8 cycloalkyl, -C 2 -C 6 alkenyl-C 3 -C 8 cycloalkyl, -C 2 -C 6 alkynyl- C 3 -C 8 cycloalkyl, or C 1 -C 6 alkoxy C 1 -C 6 alkyl; and R 11 is H, C 1 -C 6 alkyl, C 2 -C 6 alkenyl, C 2 -C 6 alkynyl, C 3 -C 8 cycloalkyl, -C 1 -C 6 alkyl-aryl, -C 2 -C 6 alkenyl-aryl, -C 2 -C 6 alkynyl-aryl, -C 1 -C 6 alkyl-heteroaryl, -C 2 -C 6 alkenyl-heteroaryl, -C 2 -C 6 alkynyl-heteroaryl, -C 1 -C 6 alkyl- heterocycloalkyl, -C 2 -C 6 alkenyl-heterocycloalkyl, -C 2 -C 6 alkynyl-heterocycloalkyl, -C 1 -C 6 alkyl-C 3 -C 8 cycloalkyl, -C 2 -C 6 alkenyl-C 3 -C 8 cycloalkyl, -C 2 -C 6 alkynyl- C 3 -C 8 cycloalkyl, or C 1 -C 6 alkoxy C 1 -C 6 alkyl; wherein each aryl group is independently phenyl or naphthyl, and each aryl is unsubstituted or substituted at one or more substitutable positions with a group that is independently C 1 -C 6 alkyl, C 2 -C 6 alkenyl, C 2 -C 6 alkynyl, C 1 -C 6 alkoxy, OPro, halo, C 1 -C 6 haloalkyl or C 1 -C 6 haloalkoxy; wherein each heteroaryl group is independently pyrrolyl, imidazolyl, triazolyl, pyridyl, pyridazinyl, pyrimidyl, pyrazinyl, triazinyl, indolyl, quinolinyl, furanyl, benzofuranyl, thienyl, or benzothienyl, and each heteroaryl is unsubstituted or substituted at one or more substitutable positions with a group that is independently C 1 -C 6 alkyl, C 2 -C 6 alkenyl, C 2 -C 6 alkynyl, C 1 -C 6 alkoxy, OPro, halo, C 1 -C 6 haloalkyl or C 1 -C 6 haloalkoxy; and wherein each heterocycloalkyl group is pyrrolidinyl, imidazolidinyl, oxazolidinyl, thiazolidinyl, tetrahydrofuranyl, piperidinyl, piperazinyl, or morpholinyl, and each heterocycloalkyl is unsubstituted or substituted at one or more substitutable positions with a group that is independently C 1 -C 6 alkyl, C 2 -C 6 alkenyl, C 2 -C 6 alkynyl, C 1 -C 6 alkoxy, OPro, halo, C 1 -C 6 haloalkyl or C 1 -C 6 haloalkoxy; R 14 is H or OH; and R 25 is OH. at each occurrence, --- is a single bond; L is absent; n is 1; R 1 is H, C 1 -C 6 alkyl, C 1 -C 6 alkoxy, OH, or -O-Pro; R 2 is H, C 1 -C 6 alkyl, C 1 -C 6 alkoxy, OH, or -O-Pro; R 3 is H, C 1 -C 6 alkyl, C 1 -C 6 alkoxy, OH, or -O-Pro, wherein Pro, at each occurrence, is independently a hydroxyl protecting group; R 10 is C 1 -C 6 alkyl, C 2 -C 6 alkenyl, C 2 -C 6 alkynyl, C 3 -C 8 cycloalkyl, -C 1 -C 6 alkyl-aryl, -C 2 -C 6 alkenyl-aryl, -C 2 -C 6 alkynyl-aryl, -C 1 -C 6 alkyl-heteroaryl, -C 2 -C 6 alkenyl-heteroaryl, -C 2 -C 6 alkynyl-heteroaryl, -C 1 -C 6 alkyl- heterocycloalkyl, -C 2 -C 6 alkenyl-heterocycloalkyl, -C 2 -C 6 alkynyl-heterocycloalkyl, -C 1 -C 6 alkyl-C 3 -C 8 cycloalkyl, -C 2 -C 6 alkenyl-C 3 -C 8 cycloalkyl, -C 2 -C 6 alkynyl- C 3 -C 8 cycloalkyl, or C 1 -C 6 alkoxy C 1 -C 6 alkyl; and R 11 is H, C 1 -C 6 alkyl, C 2 -C 6 alkenyl, C 2 -C 6 alkynyl, C 3 -C 8 cycloalkyl, -C 1 -C 6 alkyl-aryl, -C 2 -C 6 alkenyl-aryl, -C 2 -C 6 alkynyl-aryl, -C 1 -C 6 alkyl-heteroaryl, -C 2 -C 6 alkenyl-heteroaryl, -C 2 -C 6 alkynyl-heteroaryl, -C 1 -C 6 alkyl- heterocycloalkyl, -C 2 -C 6 alkenyl-heterocycloalkyl, -C 2 -C 6 alkynyl-heterocycloalkyl, -C 1 -C 6 alkyl-C 3 -C 8 cycloalkyl, -C 2 -C 6 alkenyl-C 3 -C 8 cycloalkyl, -C 2 -C 6 alkynyl- C 3 -C 8 cycloalkyl, or C 1 -C 6 alkoxy C 1 -C 6 alkyl; wherein each aryl group is independently phenyl or naphthyl, and each aryl is unsubstituted or substituted at one or more substitutable positions with a group that is independently C 1 -C 6 alkyl, C 2 -C 6 alkenyl, C 2 -C 6 alkynyl, C 1 -C 6 alkoxy, OPro, halo, C 1 -C 6 haloalkyl or C 1 -C 6 haloalkoxy; wherein each heteroaryl group is independently pyrrolyl, imidazolyl, triazolyl, pyridyl, pyridazinyl, pyrimidyl, pyrazinyl, triazinyl, indolyl, quinolinyl, furanyl, benzofuranyl, thienyl, or benzothienyl, and each heteroaryl is unsubstituted or substituted at one or more substitutable positions with a group that is independently C 1 -C 6 alkyl, C 2 -C 6 alkenyl, C 2 -C 6 alkynyl, C 1 -C 6 alkoxy, OPro, halo, C 1 -C 6 haloalkyl or C 1 -C 6 haloalkoxy; and wherein each heterocycloalkyl group is pyrrolidinyl, imidazolidinyl, oxazolidinyl, thiazolidinyl, tetrahydrofuranyl, piperidinyl, piperazinyl, or morpholinyl, and each heterocycloalkyl is unsubstituted or substituted at one or more substitutable positions with a group that is independently C 1 -C 6 alkyl, C 2 -C 6 alkenyl, C 2 -C 6 alkynyl, C 1 -C 6 alkoxy, OPro, halo, C 1 -C 6 haloalkyl or C 1 -C 6 haloalkoxy; R 14 is H or OH; and R 25 is OH.