35162-77-7

Upstream product

• 5389-87-7 1-chloro-3,7-dimethylocta-2,6-diene 
• 6138-90-5 trans-geranyl bromide 
• 24163-93-7 farnesyl bromide 
• 917-54-4 methyllithium 

Relevant academic research and scientific papers

Enzymatic cyclization reactions of geraniol, farnesol and geranylgeraniol, and those of truncated squalene analogs having C20 and C25 by recombinant squalene cyclase

The substrate specificity of squalene-hopene cyclase was investigated using the C10-C25 analogs including naturally occurring substances, e.g. geraniol (C10), farnesol (C15) and geranylgeraniol (C20). No cyclization occurred for geraniol, but a significantly high conversion ratio (64%) was observed for farnesol, yielding the cyclic sesquiterpenes consisting of 6/6-fused bicyclic ring systems. Among them, an attractive compound having C30 was produced, in the structure of which acyclic the farnesol unit is linked to the bicyclic skeleton through ether linkage. Conversion of geranylgeraniol was low (ca. 12%). The squalene analogs having C20 and C25 also were cyclized in yields of ca. 33-36%, but the analogs having the methyl group at C(7) and/or at C(11) underwent no cyclization; the large steric bulk size of C(7)-Me and/or C(11)-Me, which is arranged in α-disposition for all the pre-chair conformation, would have interacted repulsively with the cyclase recognition site near to the C(7) and/or C(11), resulting in no construction of the all-chair conformation inside the reaction cavity. A relatively low yield of geranylgeraniol indicated that a less bulky hydrogen atom must be located at C(14) for the efficient polycyclization reaction. The squalene cyclase shows remarkably broad substrate specificity to accept the truncated analogs having carbon-chain lengths of C15-C25 in addition to C 30.

Chemical and electrochemical reductions of some allyl type halides catalyzed by vitamin B12

Chemical and electrochemical reductions of some attyl type halides catalyzed by vitamin B12 have been studied. Geranyl bromide 1 and methyl (2E, 6E) 8-bromo-3,7-dimethylocta-2,6- dienoate 2 have been used as substrates and subjected to chemical and electrochemical reduction. The formation and distribution of the reaction products of these substrates can be explained by free radical mechanisms, namely by reductive reactions of some functional groups, rearrangements and intermolecular coupling of intermediate radicals.

Regio- and Stereoselective Synthesis of 1,5-Dienes Using Allylic Barium Reagents

The highly α,α' selective and sterocontrolled homocoupling reaction of allylic halides was achieved using barium reagent.The double-bond geometry of the starting allylic chloride was completely retained.The α,α' cross-coupling products were also prepared stereospecifically and regioselectively by this method.

Highly Selective Homocoupling Reaction of Allylic Halides Using Barium Metal

The highly α,α' selective and stereocontrolled homocoupling reaction of allylic halides was achieved using barium reagent.The double-bond geometry of the starting allylic chloride was completely retained. α,α' Cross-coupling products were also prepared stereospecifically and regioselectively by this method.

(Phosphine)carbonylnitrosylacylcobaltate Complexes as Acyl Transfer Reagents. Acylation of Allylic Halides, Conjugated Enones, and Quinones

The complex Co(NO)(CO)2(PPh3) is an air stable, easily handled crystalline solid, prepared from Co2(CO)8, sodium nitrite, and triphenylphosphine without isolation of the volatile intermediate Co(NO)(CO)3.Treatment of this complex with organolithium reagents at -40 deg C generated unstable acylate complexes - which readily transferred the acyl group to allylic halides to produce β,γ-unsaturated ketones, to conjugated ketones to produce 1,4-dicarbonyl compounds, and to quinones to form 4-acylcyclohexadienones.

Reaction of Organic Halides with Chlorotris(triphenylphosphine)cobalt(I)

Reaction of various types of organic halides with a monovalent cobalt complex, chlorotris(triphenylphosphine)cobalt(I) is described.Reaction of benzylic monohalides, dihalides and trihalides with CoCl(Ph3P)3 gave a coupling product with formation of a carbon-carbon single bond, double bond and triple bond, respectively, under mild and non-basic conditions.Dehalogenation of non-benzylic vicinal dihalides with the reagent took place cleanly to give an olefin in high yield.Reductive coupling of allylic halides using the reagent afforded regioselectively a 1,5-diene with retention of the stereochemistry of the carbon-carbon double bond of the allylic halides used.By using this reaction, (E,E,E,E)-squalene was stereospecifically synthesized from (E,E)-farnesyl bromide.Reaction of halohydrins with CoCl(Ph3P)3 gave exclusively a ketone in the presence of an amine or olefin through an alkylcobalt intermediate.A 1,2-hydrogen shift is involved in this reaction.Keywords - chlorotris(triphenylphosphine)cobalt(I); coupling reaction; benzylic halides; allylic halides; synthesis of 1,5-diene; squalene; halohydrin; ketone synthesis.