Oxygen → HCID 18642346, compound

Participants

Reaction Steps

33 g of (1R,4RS,5S,8R)-4,8-dimethyl-4-vinyl-2,3-dioxabicyclo[3.3.1]nonan-7-one [obtained in accordance with Example 2(a)] are dissolved in 100 ml of methanol and cooled to -70° under argon. A stream of ozone from 40 1 of oxygen/h is introduced and maintained up to saturation (pale blue colour). After 3-4 hours the source of current is switched off and the excess ozone is displaced by oxygen. 40 ml of dimethyl sulphide are added thereto and the suspension is then allowed to warm to room temperature. The methanol is distilled off and the residue is purified and separated by column chromatography on silica gel while eluting with hexane/ethyl acetate (2:1 to 1:2). After crystallization from hexane/ethyl acetate at 0° there are obtained (1R,4R,5S,8R)-4,8-dimethyl-7-oxo-2,3dioxabicyclo[3.3.1]nonane-4-carboxaldehyde [m.p. 92°] and (1R,4S,5S,8R)- 4,8-dimethyl-7-oxo-2,3-dioxabicyclo[3.3.1]-nonane-4-carboxaldehyde [m.p. 97°].

Provenance & Evidence