Patent ID: 11884613
Assignee: CHIROGATE INTERNATIONAL INC.
Field: Organic fine chemistry (Chemistry)
Classification: CPC C | IPC C

Claim 6:
7. The process according to claim 1 for preparing compound of Formula 4b:, wherein Y is —CH2OP or —COOR1; P is H or a hydroxyl protective group; and R1 is C1-7-alkyl, aryl or aralkyl, each of which is unsubstituted or substituted by C1-4-alkyl, C2-7-alkenyl, C2-7-alkynyl, nitro, halogen or alkoxy, the process comprising the steps of:
(1″) reacting an optically enriched compound of Formula (R)-1:, wherein X is F, Cl, Br, I, or —OTs; P1 is a hydroxyl protective group; and Y is as defined above, with a cuprate derived from a compound of Formula L1b, Formula L2b, or Formula L3b,, wherein X1 is Cl, Br, or I; and P2 is a hydroxyl protective group, to form a compound of Formula 2b:, wherein P, X and Y are as defined above;

(2′″) methylenation of a ketone radical of the compound of Formula 2b to form a compound of Formula 3b:, wherein P, X and Y are as defined above;

(3′″) performing an intramolecular cyclization reaction to the compound of Formula 3b to form a compound of Formula 4b:, wherein P and Y are as defined above; and

(4′″) optionally performing a deprotecting reaction for removing P1 and/or P2.