Diisobutylaluminum hydride → [2-(3-Methyl-cyclohex-3-enyl)ethoxymethyl]-benzene

Beteiligte Stoffe

Reaktionsschritte

5-(2-Benzyloxy-ethyl)-cyclohex-1-enecarboxylic acid methyl ester (Intermediate R3 obtained above in Example R1 in accordance with Method R) was reduced with DIBAL. The resulting alcohol (Intermediate R7, 1.18 g, 4.81 mmol) in THF (20 mL) at 0° C. was treated with sulfur trioxide-pyridine. (1.15 g, 7.21 mmol) for 3 h. LiAlH4 (15 mL, 15 mmol) was injected into the mixture at 0° C. The solution was allowed to warm to rt for 18 h. The mixture was subjected to an aqueous work-up and purified by chromatography to give [2-(3-methyl-cyclohex-3-enyl)-ethoxymethyl]-benzene (Intermediate R8, 0.90 g, 82%). Deprotection with Na/NH3 and subsequent “Swern” oxidation produced (3-methyl-cyclohex-3-enyl)-acetaldehyde (Intermediate R9). (3-methyl-cyclohex-3-enyl)-acetaldehyde (Intermediate R9) was subjected to the applicable steps combined from Method A and Method P to yield 4-(3-methyl-cyclohex-3-enylmethyl)-1,3-dihydro-imidazol-2-one (Compound 57).

Herkunft & Nachweise