6244-44-6

Upstream product

• 28256-59-9 propylidene cyclohexane oxide 
• 13154-14-8 1-propenylmagnesium bromide 
• 108-94-1 cyclohexanone 
• 1123-34-8 1-allyl-1-cyclohexanol 
• 623-70-1 ethyl (E)-crotonate 
• 23708-47-6 1,4-bis(bromomagnesium)butane 
• 111-24-0 1,5-dibromo-pentane 
• 623-43-8 methyl crotonate 
• 16212-05-8 (allylsulfonyl)benzene 

Downstream Products

• 79405-36-0 1-(cyclohexylidene)-2-propanol 
• 4481-78-1 1-oxa-spiro[5.5]undecan-2-one 
• 16149-84-1 9-methyl-7-oxaspiro<5.4>decan-8-one 

Relevant academic research and scientific papers

Exploration of the diastereoselectivity in an unusual Grignard reaction and its application towards the synthesis of styryl lactones 7-: Epi -(+)-goniodiol and 8- epi -(-)-goniodiol

An unusual diastereoselective Grignard reaction is explored, where the Grignard reagents are derived from 1,n-dihaloalkanes. A steric bias due to the presence of a quaternary centre adjacent to the acetonide ester at the benzylic position is responsible for the formation of an intramolecularly reduced product in almost quantitative yield. This steric hindrance is responsible for the diastereoselectivity observed with a variety of aromatic as well as aliphatic esters. The unusual Grignard reaction furnishes long chain secondary alcohols possessing a terminal olefin, which are synthetically important intermediates. As an application of this method, the diastereoselective synthesis of styryl lactones viz. 7-epi-(+)-goniodiol (29) and 8-epi-(-)-goniodiol (30) has been achieved.

Arene-catalysed reductive desulfonylation and desulfinylation reactions: New routes for alkyllithiums

The reactions of alkyl phenyl sulfones (1) with an excess of lithium powder and a catalytic amount of naphthalene (8 mol %) in the presence of a carbonyl compound or chlorotrimethylsilane (Barbier-type conditions) in THF at temperatures ranging between -78 and 20°C leads, after hydrolysis, to the expected products (2) arising from the corresponding alkyllithium generated in situ. When the same methodology is applied to sulfolene (3) or different alkyl phenyl sulfoxides (6), cyclic sulfinates 5 or products 2 are, respectively, obtained, the yields being, in general modest.

Photosensitized Cis/Trans Izomerization of 1-(1-Propenyl)cycloalkenes

The photosensitized cis/trans isomerization of a series of 1-(1-propenyl)cycloalkenes is reported.A plot of the photostationary state trans/cis ratio vs the sensitizer triplet energy for 1-(1-propenyl)cyclopentene shows a constant trans/cis ratio of ca. 1.0 with high-energy sensitizers (ET>61 kcal/mol).The plot shows one maxima at ET ca. 55 kcal/mol with low-energy sensitizers (ET61 kcal/mol).This type of plot is very similar to those obtained with acyclic dienes such as piperylene.The 1-(1-propenyl)cyclohexene system shows a similar plot with high-energy sensit izers, but with low-energy sensitizers this system shows two maxima occurring at 56 and 47 kcal/mol, respectively.This double-maxima plot is rationalized by an unsually low trans/cis decay ratio for the s-cis relaxed triplet state of the 1-(1-propenyl)cyclohexene system.This double maxima is not observed in other diene systems due to a high trans/cis decay ratio for their s-cis relaxed triplet states.The photosensitized cis/trans isomerization of 2-ethylidene-10-methyl-1(9)-octalin was also studied as a model for a conformationally locked s-trans system.The 1-(1-propenyl)cycloheptene system undergoes photosensitized cis/trans isomerization, but photostationary cis/trans isomerization data could not be obtained due to a very efficient photosensitized dimerization of this diene system.