65489-13-6Relevant articles and documents
Synthesis of Pyranocyclopentaindolines Representing the Western Sections of Janthitrem B, JBIR-137, and Shearinine G
Fresia, Marvin,Lindel, Thomas
supporting information, (2022/02/05)
The synthesis of the ABCD tetracyclic partial structures of the fungal indole diterpenes janthitrem B, JBIR-137, and shearinine G is reported. The route starts from 5-formylated indoline that is coupled to a dihydropyran moiety, followed by Prins cyclization. A diene was obtained that was oxygenated in a divergent manner. The hydroxylated tetracyclic western half of janthitrem B was obtained in eight steps and 10 % overall yield. We also share our experience with alternative approaches passing via alkynylated precursors. This includes the gold-catalyzed cycloisomerization of a 6-ethynyl-5-prenylindoline.
Unsaturated aldehydes as potential lilial replacers
Schroeder, Martin,Mathys, Marion,Ehrensperger, Nadja,Büchel, Michelle
, p. 1651 - 1673 (2015/02/19)
A series of Claisen rearrangements was undertaken in order to find a replacement for Lilial (= 3-(4-(tert-butyl)phenyl)-2-methylpropanal), a high-tonnage perfumery ingredient with a lily-of-the-valley odour, which is a CMR2 material [1]. 5,7,7-Trimethyl-4-methyleneoctanal (10), the synthesis of which is described, became the main lead. It possesses an odour which is very close to that of Lilial but lacks its substantivity. Aldehydes with higher molecular weights than that of 10 were, therefore, synthesised in order to boost substantivity and to understand the structural requirements for a 'Lilial' odour. The aldehydes were obtained via Claisen rearrangements of 'exo-methylidene' vinyl ethers, allenyl vinyl ethers, or allenyl allyl ethers. Alternatively, coupling of terminal alkynes with allyl alcohols led to the desired aldehydes. Derivatives of 10 and their sila analogues were also synthesised. The olfactory properties of all synthesised molecules were evaluated for possible structure-odour relationships (SOR).
Reactivity pattern of bis(propargyloxy) disulfides: Tandem rearrangements and cyclizations
Braverman, Samuel,Pechenick-Azizi, Tatiana,Gottlieb, Hugo E.,Sprecher, Milon
experimental part, p. 1741 - 1750 (2011/07/09)
Thirty-five substituted bis(propargyloxy) disulfides were successfully prepared in good to excellent yields, and their reactivity was found to be strongly dependent on the substitution pattern of the reactant. Inter alia they undergo surprising tandem sigmatropic rearrangements and cycloadditions. Three heretofore unknown product types were isolated and fully characterized: 6,7-dithiabicyclo[3.1.1]heptan-2-one 6-oxide derivatives, two isomeric 1,2-dithiete 1,1-dioxides (α,β-unsaturated four-membered cyclic thiosulfonates) from bis(propargyloxy) disulfides with α- or γ-alkyl-substituted propargyl groups, and two isomeric 2-oxa-5,7-dithiabicyclo[2.2.1]heptane 5-oxides from bis(propargyloxy) disulfides with α-tert-butyl- or α,α-dialkyl-substituted propargyl groups. Georg Thieme Verlag Stuttgart - New York.
