C(C(C)(CCCCCO)C)#N.[OH:12][C:13]1[C:20](O)=[C:19](CC)[CH:18]=[CH:17][C:14]=1[CH:15]=[O:16].C1(P(C2C=CC=CC=2)C2C=CC=CC=2)C=CC=CC=1.N(C([O:52][CH2:53][CH3:54])=O)=NC(OCC)=O>C1COCC1>[CH2:19]([C:18]1[C:53]([OH:52])=[CH:54][C:15]([OH:16])=[C:14]([CH:17]=1)[CH:13]=[O:12])[CH3:20]A 50 mL dry THF solution of the above prepare 2-cyano-2-methyl-7-hydroxyheptane and 2,3-dihydroxy-4-ethylbenzaldehyde was stirred at room temp. To this solution added triphenylphosphine (17.91 g, 68.3 mmol) and finally diethyl azodicarboxylate (11.89 g, 68.3 mmol). The reaction was stirred at room temp for 2 h 15 min. and then quenched with saturated NH4Cl solution. The THF was removed under vacuum and the resulting residue was dissolved in EtOAc and the EtOAc solution was washed with brine. The organic layer was dried over MgSO4. Filtration and solvent removal gave an orange solid. The product was purified by Waters Prep 500 chromatography using silica gel as a solid support and eluting with a gradient of 10% to 30% EtOAc/Hexane over 50 min. The desired product was obtained as a yellow oil (10.50 g, 51%).
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