Geraniol → Citral

Geraniol (7.0 g, 0.045 mol, 1 equiv.), manganese (IV) dioxide (100.0 g) and dichloromethane (500 ml) were stirred together at ambient temperature overnight. The mixture was filtered through Celite™, and the filtrate concentrated in vacuo to yield geranial (5.42 g, 80%). A cooled (−15° C.), stirred suspension of methyltriphenyl-phosphonium iodide (16.0 g, 0.039 mol, 1.1 equiv.) in tetrahydrofuran (50 ml) and diethyl ether (50 ml) was treated with n-butyllithium (2.5 M; 16 ml, 0.039 mol, 1.1 equiv.). After 0.25 hours, geranial (5.42 g, 0.036 mol, 1 equiv.) was added and the mixture allowed to stir at ambient temperature for 1 hour. The mixture was partitioned between diethyl ether (200 ml), water (200 ml) and petroleum ether b.p. 40-60° C. (200 ml), and the organic layer dried (MgSO4) and concentrated in vacuo to yield a crude oil which was subjected to column chromatography over Florisil (100% hexane) to give the nonatriene as a colourless oil (3.42 g, 64%).

1. filtrationThe mixture was filtered through Celite™
2. concentrationthe filtrate concentrated in vacuo

ORD record

ord-c97e769954354b0e9bbb3785df25d045

Source dataset

uspto-grants-2010_10

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US07820153B2