hydrogen; palladium on activated charcoal in methanol T=25°C; P=760 Torr; 7 h;

lead(IV) acetate in benzene T=40°C; P=60800 Torr; 24 h;

1: tetrahydropyran-2-one With n-butyllithium; diisopropylamine in tetrahydrofuran; hexane T=-78°C; Metallation; 2: 1-iodo-propane in tetrahydrofuran; N,N,N',N',N'',N''-hexamethylphosphoric triamide; hexane T=-78 - 20°C; Alkylation;

1: 41 percent / HMPA, diisopropylamine, n-butyllithium / tetrahydrofuran / 5 h / -78 - 25 °C 2: 99 percent / H2 / 5percent Pd on carbon / methanol / 7 h / 25 °C / 760 Torr View Scheme