153060-91-4

Upstream product

• 140479-11-4 (+)-(3R,5S)-4,4,5-trimethyl-8-methylidene-1-oxaspiro<2.5>octane 
• 140479-12-5 (+)-(3S)-2,2,3-trimethyl-6-methylidenecyclohexan-1-one 
• 634611-86-2 ((3S,4S,6S)-5,5,6-Trimethyl-1-oxa-spiro[2.5]oct-4-yl)-methanol 
• 634611-87-3 ((3R,4S,6S)-5,5,6-Trimethyl-1-oxa-spiro[2.5]oct-4-yl)-methanol 
• 153060-92-5 (-)-(1S,3S)-2,2,3-trimethyl-6-methylidenecyclohexane-1-methanol 

Relevant academic research and scientific papers

Electrophilic Cyclization of 1,6-Dienes Containing an Allylsilane Moiety - Enantioselective Synthesis of cis- and trans-γ-Irone

In this paper, we report the first examples of Lewis acid and mercuric trifluoroacetate promoted cyclizations of 1,6-dienes containing an allylsilane moiety. Mercuric trifluoroacetate has been proved to be the reagent of choice leading to methylenecyclohexane derivatives in good yields and with complete regioselectivity albeit with poor diastereoselectivity. Using this methodology a stereodivergent synthesis of enantiomerically pure (-)-(2S,6R)-cis-γ -irone and (-)-(2S,6S)-trans-γ-irone, two precious aroma constituents, has been accomplished. This represents an innovative approach with respect to previous syntheses of γ-irones. Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003.

Preparation of Optically Active Flowery and Woody-Like Odorant Ketones via Corey-Chaykovsky Oxiranylation: Irones and Analogues

α-, β-, and γ-Irones and analogues have been prepared from optically active (+)-1, (+)-6a,b, and (+)-17, via a Corey-Chaykovsky oxiranylation (Me2S, Me2SO4, Me2SO, NaOH) followed by isomerisation (SnCl4 or MgBr2). (+)-Dihydrocyclocitral (19a), obtained from (-)-citronellal, and analogue (+)-19b, were condensed with various ketones to afford (+)-21a-f, and after hydrogenation (+)-22a-f.A mild oxidative degradation of aldehydes (+)-trans- and (-)-cis-8a,b to ketones (-)-16a,b, as well as olfactive evaluations, 13C-NMR assignments, and absolute configurations of the intermediate epoxides, aldehydes, and alcohols are presented.

Cyclic ketones and their use as perfuming ingredients

Novel compounds of formula STR1 wherein the dotted lines indicate the location of a single or double bond, symbol R1 stands for a hydrogen atom or a methyl radical, symbol R2 represents a linear or branched, saturated or unsaturated, C1 to C4 alkyl radical, provided that R1 is not hydrogen when R2 represents a methyl or n-propyl radical and the ring is saturated. Compounds (Ia) are useful as perfuming ingredients. A process for their preparation is disclosed.