Disila-okoumal: a silicon analogue of the ambergris odorant okoumal.
Two-fold sila-substitution (C/Si exchange) in the saturated ring of the tetrahydronaphthalene skeleton of the ambery odorant okoumal (5) provides disila-okoumal (6). The okoumal isomers 5 a-d were synthesized from 1-(5,5,8,8-tetramethyl-5,6,7,8-tetrahydro-2-naphthyl)ethanone (7), and the silicon analogues 6 a-d were synthesized from 1-(5,5,8,8-tetramethyl-5,8-disila-5,6,7,8-tetrahydro-2-naphthyl)ethanone (8). Detailed olfactory properties of 5 a-d and 6 a-d are reported, together with the respective threshold values. All enantiomers of okoumal and disila-okoumal exhibit typical ambery odor notes with woody facets, as is characteristic of okoumal and karanal, but a stereocenter at the 2-position was found to be of utmost importance for the odor thresholds; the lowest value of 0.31 ng per L air was measured for the 2R-configured silicon compounds 6 a and 6 c.
Büttner
Matthias W
MW
Universität Würzburg, Institut für Anorganische Chemie, Am Hubland, 97074 Würzburg, Germany.
Burschka
Christian
C
Junold
Konstantin
K
Kraft
Philip
P
Tacke
Reinhold
R
D018648:Ambergris; D009812:Odorants; D012825:Silicon; D013237:Stereoisomerism
D018648:Ambergris; D012825:Silicon