1: Methyltriphenylphosphonium bromide With n-butyllithium in tetrahydrofuran; hexane 0.5 h; 2: (3aR,5S,6S,6aR)-6-(benzyloxy)-tetrahydro-2,2-dimethylfuro[2,3-d][1,3]dioxol-5-carbaldehyde in tetrahydrofuran; hexane T=0°C; 3 h; Inert atmosphere;

1: (tributylstannyl)methyl 2,4,6-triisopropylbenzoate With n-butyllithium in tetrahydrofuran; hexane T=-78°C; 0.0833333 h; Inert atmosphere; 2: (3aR,5S,6S,6aR)-6-(benzyloxy)-tetrahydro-2,2-dimethylfuro[2,3-d][1,3]dioxol-5-carbaldehyde in tetrahydrofuran; hexane T=-78°C; 0.5 h; Inert atmosphere; 3: With water; sodium hydrogencarbonate in tetrahydrofuran; hexane T=-78°C; Inert atmosphere; optical yield given as percent de;