81925-76-0

Upstream product

• 3756-30-7 1-iodo-2-methyl-2-propene 
• 93-89-0 benzoic acid ethyl ester 
• 100-52-7 benzaldehyde 
• 93-58-3 benzoic acid methyl ester 
• 563-47-3 3-Chloro-2-methylpropene 
• 10364-94-0 1-benzoylimidazole 
• 1458-98-6 2-methyl-3-bromo-1-propene 
• 98-88-4 benzoyl chloride 
• 67883-62-9 2-methylallyltributyltin 

Downstream Products

• 5650-07-7 3-methyl-1-phenyl-but-2-en-1-one 
• 52813-35-1 3-methyl-1-phenylbut-3-en-1-one 
• 1423078-89-0 C₁₅H₂₀O₂ 

Relevant academic research and scientific papers

Metal zinc-promoted gem-bisallylation of acid chlorides with allyl chlorides in the presence of chlorotrimethylsilane

Treatment of acid chlorides (2) with allyl chlorides (1) in the presence of zinc dust and a catalytic amount of chlorotrimethylsilane (TMSCl) in THF brought about highly facile and effective coupling to give the corresponding gem-bisallylation products, 4-hydroxy-penta-1,6-dienes (3), in good to excellent yields. These reactions are assumed to proceed through allylzinc intermediates generated in situ.

Indium(III) chloride-catalyzed coupling reaction of acid chlorides and allylic tins

Allylic tributyltins and acid chlorides are effectively coupled to yield allylic ketones in indium(III) chloride-catalyzed reactions. In the case of γ-unsubstituted allylic tins, the assistance of a phosphine is essential to prevent further allylation of the produced ketones.

Organometallic-type reactions in aqueous media mediated by indium. Allylation of acyloyl-imidazoles and pyrazoles. Regioselective synthesis of β,γ-unsaturated ketones.

Indium mediated coupling of allylic bromide with acyloyl-imidazoles or pyrazoles in aqueous media gives the corresponding tertiary alcohols or ketones in good yield. The reaction provides a facile regioselective synthesis of P,β,γ-unsaturated ketones and its usefulness is demonstrated by the synthesis of the monoterpene artemesia ketone.

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

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).

Carbon-Carbon Bond-Forming Reactions Using Cerium Metal or Organocerium(III) Reagents

Carbon-carbon bond-forming reactions using cerium metal or organocerium(III) reagents have been investigated.Cerium amalgam is an effective reagent for the chemoselective preparation of homoallylic alcohols from allyl halides and carbonyl compounds.These same reagent can also be satisfactorily employed for the Reformatsky-type reaction of α-halo esters with carbonyl compounds.It has been shown that organocerium(III) reagents are conveniently generated by the reaction of organolithiums with cerium(III)iodide or cerium(III)chloride.The reagents are less basic thanorganolithiums or Grignard reagents, and they react cleanly at -78 to -65 deg C with various carbonyl compounds to afford the addition products in high yields, even though the substrates are susceptible to enolization or metal-halogen exchange with simple organolithiums.The same reagents react also with α,β-unsaturated compounds to yield 1,2-addition products in high selectivity.

Process for the preparation of α,β-and β,γ-unsaturated ketones

α,β-and β,γ-unsaturated ketones of formula STR1 possessing a double bond in one of the positions indicated by the dashed lines and wherein R and R1 have the meaning given above and index n stands for integer 1 or 2, are obtained by a process which consists in treating with a strong base in an inert organic solvent a diallyl carbinol of formula STR2 wherein symbol R represents a primary, secondary or tertiary alkyl radical, or a substituted or unsubstituted phenyl radical, and symbol R1 represents a hydrogen atom or an alkyl radical.

FRAGMENTATION OF HOMOALLYLIC ALKOXIDES. SYNTHESIS OF PROPENYL and 2-METHYLPROPENYL KETONES FROM CARBOXYLIC ESTERS

An efficient two-step synthesis of propenyl and 2-methylpropenyl ketones from carboxylic esters is described which uses as the key step the fragmentation of a potassium dihomoallylic alkoxide under mild thermolytic conditions.