Patent ID: 6982329

Claim:
A method comprising: a) providing a compound of the formula: wherein: each of C1, C2, C4, C11, C12, C15 and C16 is independently substituted with i) one of: ═O, ═C(R 1 )(R 1 ), —C(R 1 )(R 1 )(C(R 1 )CR 1 )) n — and —(O(C(R 1 )(R 1 )) n O)— wherein n ranges from 1 to about 6; or ii) two of the following, which are independently selected: —X, —R 1 and —OR 2 ; C3 is substituted with hydrogen or -ZR 3 ; each of C8, C9 and C14 is independently substituted with one of —X, —R 1 or —OR 2 ; C17 is substituted with two —OR 2 groups or is a ketal; R 1 at each occurrence is independently selected from H and C 1-30 organic moiety that may optionally contain at least one heteroatom selected from the group consisting of boron, halogen, nitrogen, oxygen, silicon and sulfur, where two geminal R 1 groups may together form a ring with the carbon atom to which they are both bonded; R 2 is H or a protecting group such that —OR 2 is a protected hydroxyl group, where vicinal —OR 2 groups may together form a cyclic structure which protects vicinal hydroxyl groups, and where geminal —OR 2 groups may together form a cyclic structure which protects a carbonyl group, with the proviso that either or both of —OR 2 at C6 and C7 represents a carbonyl or protected carbonyl group; R 3 is benzoyl or substituted benzoyl; X represents fluoride, chloride, bromide and iodide; and Z is selected from O, S and NR 1 ; b) contacting the compound with reagents comprising copper iodide and t-butyl hydroperoxide to provide a mixture; and c) maintaining the mixture of step b) under oxidizing conditions to convert to compound to a product having a carbon skeleton and an α,β-unsaturated ketone moiety as present in formula (4)