33698-67-8Relevant academic research and scientific papers
172. β-Cleavage of Bis(homoallylic) Potassium Alkoxides. Two-Step Preparation of Propenyl Ketones from Carboxylic Esters. Synthesis of ar-Turmerone, α-Damascone, β-Damascone, and β-Damascenone
Snowden, Roger L.,Linder, Simon M.,Muller, Bernard L.,Schulte, Karl H.
, p. 1858 - 1878 (2007/10/02)
The transformation of 36 bis(homoallylic) alcohols VII to alkenones IX and X via β-cleavage of their potassium alkoxides VIIa in HMPA has been investigated (cf.Scheme 2).These studies have established an order of β-cleavage for 2-propenyl, 1-methyl-2-propenyl, 2-methyl-2-propenyl, 1,1-dimethyl-2-propenyl, and benzyl groups in alkoxides 49a-56a and have allowed a comparison between the β-cleavage reaction and the oxy-Cope rearrangement in alkoxides 74a-83a.As illustrative synthetic applications, a two-step preparation of propenyl ketones 15-42 from carboxylic esters is described, together with syntheses of ar-turmerone (48), α-damascone ((E)-71), β-damascone ((E)-109), and β-damascenone ((E)-111).
PALLADIUM-CATALYZED CROSS COUPLING OF ALLYL HALIDES WITH ORGANOTIN REAGENTS: A METHOD OF JOINING HIGHLY FUNCTIONALIZED PARTNERS REGIOSELECTIVELY AND STEREOSPECIFICALLY.
Sheffy,Godschalx,Stille
, p. 4833 - 4840 (2007/10/11)
The palladium-catalyzed reaction of allyl halides with aryl- and vinyltin reagents gives high yields of cross-coupled products. In the presence of 1-3 atm of carbon monoxide, ketones are obtained, resulting from cross coupling accompanied by carbon monoxide insertion. The reaction is mild and tolerant of a wide variety of functionalities (OH, OR, CN, CO//2R, CHO) on either the allyl chloride or the tin reagent. Coupling at the allyl halide partner proceeds with inversion of configuration at the carbon bearing the halide, with retention of geometry at the allylic double bond, and with a regioselectivity for the least-substituted carbon in the allylic framework. Retention of double-bond geometry is observed in the vinyltin partner.
CONDENSATION DES ORGANOMAGNESIENS SUR LES CHLORUSES D'ACIDE DANS LE TETRAHYDROFURANNE A BASSE TEMPERATURE
Dubois, Jacques-Emile,Lion, Claude,Arouisse, Abdelmajid
, p. 1083 - 1088 (2007/10/02)
The condensation of a Grignard reagents with hindered acid chlorides in THF at low temperature, yields ketones which are generally difficult to obtain and avoids the side reaction caused with a CuCl catalyst.Applied to unsaturated Grignard reagents and acid chlorides, this method also yields unsaturated ketones, such as the Artemisia ketone.
Regiochemical Control in Intramolecular Photochemical Reactions of 1,5-Hexadien-3-ones and 1-Acyl-1,5-hexadienes
Wolff, Steven,Agosta, William C.
, p. 1292 - 1299 (2007/10/02)
Both 1,5-hexadien-3-ones (7) and 1-acyl-1,5-hexadienes (8) generally undergo intramolecular photochemical cyclization by way of 1,5 (crossed) closure (see 2), as do other derivatives of 1,5-hexadienes (1).Through study of the photochemistry of 14 members
