[C:1]([O:4][C:5]1[C:10]([CH3:11])=[C:9]([CH3:12])[C:8]([O:13][C:14](=[O:16])[CH3:15])=[C:7]([CH3:17])[C:6]=1[CH2:18][CH2:19][C@:20]([O:24]C(C1C(C(O)=O)=CC=CC=1)=O)([C:22]#[CH:23])[CH3:21])(=[O:3])[CH3:2].Cl>CO.[OH-].[Na+]>[C:1]([O:4][C:5]1[C:10]([CH3:11])=[C:9]([CH3:12])[C:8]([O:13][C:14](=[O:16])[CH3:15])=[C:7]([CH3:17])[C:6]=1[CH2:18][CH2:19][C@:20]([CH3:21])([OH:24])[C:22]#[CH:23])(=[O:3])[CH3:2]A solution of 600 mg (1.25 mmol) of (S)-(+)-1,2-benzenedicarboxylic acid[3-[2,5-bis(acetyloxy)-3,4,6-trimethylphenyl]-1-ethynyl-1-methylpropyl]ester (Example 9) in 10 mL of methanol and 10 mL of 1.0N NaOH was degassed with argon, and heated under reflux for 1.0 h. It was cooled to 0° C. and treated with 100 mL of cold 1.0N HCl. It was then extracted with ether (3×100 mL). The extracts were combined, washed with saturated sodium bicarbonate solution (3×100 mL) dried over MgSO4, and filtered. Dry pyridine (1mL) was added to the filtrate which was concentrated to near dryness at reduced pressure. The residue was cooled to 0° C. and treated with 3 mL of dry pyridine and 3 mL of acetic anhydride. The resultant solution was kept under argon at 0° C. for 3.0 h, then taken into 100 mL of cold 1N HCl. It was then extracted with ether (3×100 mL). The ether extracts were combined, washed with cold 1.0N HCl (2×100 mL), saturated sodium bicarbonate solution of (3×100), brine (1×100 mL), and dried over MgSO4. The crude product (369 mg) was crystallized twice from ether-hexane (1:2) to give (S)-(+)-5-[2,5-bis(acetyloxy)-3,4,6-trimethylphenyl]-3-methyl-1-pentyn-3-ol as a white solid (114 mg): mp 96°-102° C., [α]D25 +14.30° (c 0.965, ethanol: [α]D25 +17.17° (CHCl3)
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