100483-74-7

Upstream product

• 96-17-3 2-Methylbutyraldehyde 
• 925-90-6 ethylmagnesium bromide 
• 124718-82-7 trans-3,4-epoxyhexane 
• 17042-16-9 4-methyl-3-hexanone 
• 615-29-2 4-methyl-3-hexanol 
• 671795-46-3 sec-butylmagnesium bromide 
• 123-38-6 propionaldehyde 
• 1589-07-7 (3S^*,4R^*)-4-hydroxy-3-methylhexene 
• 56577-17-4 (1S,2S)-1-Ethyl-2-methylbutylamin 
• 56577-21-0 (1R,2S)-1-Ethyl-2-methylbutylamin 
• 73153-94-3 (R)-2-Ethyl-1-methylbutylamin 
• 93827-11-3 Methanesulfonic acid (R)-2-ethyl-2-hydroxy-1-methyl-butyl ester 
• 93827-11-3 (S)-3-ethyl-2-methanesulfonyloxy-3-pentanol 
• 65437-07-2 (R)-3-Ethyl-pentane-2,3-diol 

Downstream Products

• 93826-91-6 (R)-3,3,3-Trifluoro-2-methoxy-2-phenyl-propionic acid (S)-1-ethyl-2-methyl-butyl ester 
• 93826-91-6 (R)-3,3,3-Trifluoro-2-methoxy-2-phenyl-propionic acid (R)-1-ethyl-2-methyl-butyl ester 

Relevant academic research and scientific papers

Synthesis of β-Methyl Alcohols: Influence of Alkyl Chain Length on Diastereoselectivity and New Attractants of Rhynchophorus ferrugineus

The diastereoselectivity of adducts in the addition reaction via the Felkin-Anh model is affected significantly by the steric effect of bulky groups. However, the influence of steric alkyl chain length has not been studied for the diastereoselectivity. In this work, we present a new strategy for the racemic synthesis of β-methyl alcohols to obtain various diastereomer ratios using the Felkin-Anh model. The addition of alkyl Grignard reagents to α-methyl aldehydes afforded diastereomer ratios of threo/erythro ≈ 2:1, while the reduction in structurally related ketones using LiAlH4 afforded ratios of threo/erythro ≈ 1:1. The experimental data showed no effect of alkyl chain length on either side on the stereoselectivity of adducts. All synthesized analogues were evaluated for attractiveness to Rhynchophorus ferrugineus weevils in the field. Five novel derivatives, including two alcohols and three ketones, were found to attract weevils in the field trials. Among them, 3-methyldecan-4-one (5b) and 4-methyldecan-5-ol (11a) were found to be the most attractive to the insects.

-WITTIG SIGMATROPIC REARRANGEMENT OF CROTYL PROPARGYL ETHER SYSTEM; AN EMERGING TOOL FOR CONTROL OF ACYCLIC STEREOCHEMISTRY

The -Wittig rearrangement of properly designated (E)- and (Z)-crotyl propargyl ether system has been shown to exhibit a remarkably high degree of threo- and erythro-selection, respectively, and the stereochemical outcomes are discussed on mechanistic grounds.Some useful transformations of the rearrangement product are also described within the context of the formal total synthesis of (+/-)-oudemansin.Further, the high level of diastereoselection is maintained in the reaction of the α-methylcrotyl counterparts, together with the exclusive formation of the (E)-olefinic bond.

COMPLETELY STEREOSPECIFIC 1,2-MIGRATION OF ALKYL GROUPS IN Et2AlCl PROMOTED PINACOL-TYPE REARRANGEMENT

Completely stereospecific 1,2-migration of alkyl groups was achieved in Et2AlCl-promoted pinacol-type rearrangement of chiral β-mesyloxy alcohols to give optically pure α-alkyl ketones including both enantiomers of 4-methyl-3-hexanone, an alarm pheromone of ant.

Stereochemistry of Aliphatic Carbocations, 12. Alkyl Shifts between Secondary Carbon Atoms

Several optically active, β-branched alkylamines have been synthesized from amino acids.The corresponding amines were obtained from isobutyraldehyde and 2-methylbutanal (37), respectively.The stereochemistry at the terminus of 1,2-methyl shifts has been elucidated in the nitrous acid deaminations of 4 and 21.Predominant, although incomplete inversion at the migration terminus is consistent with conformational control rather than neighboring group participation.The deamination of 31 involves a degenerate 1,2-ethyl shift and a nondegenerate 1,2-methyl shift, the reverse holds for 44.Complete inversion at the origin of the methyl migrations and the absence of subsequent retrogressive H shifts strongly support the intermediacy of methyl-bridged carbocations.Partial racemization at the origin of the ethyl migrations has been traced to proton shifts within ethyl-bridged intermediates.Rearranged open cations contribute significantly to the overall reaction if micelles are produced by self-aggregation of the alkylammonium ions.

Stereochemistry of Aliphatic Carbocations, 13. Protonated Cyclopropanes as Intermediates in 1,2-Alkyl Shifts

The nitrous acid deamination of 2-ethyl-1-methylbutylamine (10), 1,2-diethylbutylamine (35), and 2-ethyl-1-methylpentylamine (43) has been studied with respect to 1,2-alkyl shifts.Optically active and deuterated amines were employed whenever possible.The structure, configuration, and deuterium distribution of various products (e. g. 16 from 10, 40 and 48 from 35, 56 from 43) are most reasonably explained in terms of alkyl-bridged intermediates (corner-protonated cyclopropanes) which isomerize via proton shifts from corner to corner.The alternative interconversion of open ions via 1,3-H shifts is incompatible with our experimental results.