91049-45-5

Upstream product

• 691-37-2 4-Methyl-1-pentene 
• 103260-84-0 4,5-diacetoxy-2-methyl-pent-2-ene 
• 158393-61-4 2-Diazo-4-methyl-pentanoic acid (1R,2S,5R)-2-isopropyl-5-methyl-cyclohexyl ester 
• 173917-47-0 1-benzyloxy-4-methylpentan-2-ol 
• 125990-20-7 phyllofoliaspongin 
• 926-56-7 4-methyl-1,3-pentadiene 
• 103273-35-4 4-methyl-pent-3-ene-1,2-diol 

Downstream Products

• 23850-78-4 4-methyl-1,2-epoxypentane 
• 24347-54-4 (S)-(-)-4-methyl-1,2-pentanediol 
• 111221-87-5 2-hydroxy-4-methylpentyl-p-toluenesulfonate 

Relevant academic research and scientific papers

Cyclodehydration and Chlorination of Simple Diols with Triphenylphosphine and tert-Butyl Hypochlorite

The reagent triphenylphosphine-tert-butyl hypochlorite converts 1,4-diols into the corresponding tetrahydrofurans and 1,2-diols into a mixture of the regioisomeric chlorohydrins and the epoxides at -78 deg C followed by warming to ambient temperature (ca. 30 deg C).Symmetrical diols give largely chlorohydrins and dichlorides.

Site-selective catalysis: Toward a regiodivergent resolution of 1,2-diols

This paper demonstrates that the secondary hydroxyl can be functionalized in preference to the primary hydroxyl of a 1,2-diol. The site selectivity is achieved by using an enantioselective organic catalyst that is able to bond to the diol reversibly and covalently. The reaction has been parlayed into a divergent kinetic resolution on a racemic mixture, providing access to highly enantioenriched secondary-protected 1,2-diols in a single synthetic step.

Osmium tetroxide in poly(ethylene glycol) (PEG): A recyclable reaction medium for rapid asymmetric dihydroxylation under Sharpless conditions

PEG (400) has been used as a recyclable and rapid reaction medium for the asymmetric dihydroxylation of olefins; Sharpless ligand is efficiently recovered and recycled with good enantioselectivity.

N-(α-chloroalkyloxycarbonyl)pyrrolidines as a source of oxygenated d1- reagents

Reaction of the N-(α-chloroalkyloxycarbonyl)pyrrolidines 1 with lithium powder and a catalytic amount of 4,4'-di-tertbutylbiphenyl (DTBB, 2.5 mol-%) in the presence of different electrophiles [iBuCHO, tBuCHO, PhCHO, Et2CO, (CH2)5CO, PhCOMe, Ph2CO, MeaSiCl], in THF at temperatures ranging between -78 and -60°C leads after hydrolysis with water, to the expected functionalized carbamates 2. Deprotection of compounds 2, derived from carbonyl compounds, with lithium hydroxide in a mixture of ethanol and water at 80°C affords the corresponding 1,2-diols 3.

Preparation of optically active α-Silylcarbonyl compounds using asymmetric alkylation of α-Silylacetic esters and asymmetric metal-carbene insertion into the Si-H bond.

Substituted α-silylacetic esters have been prepared in good yields and with reasonable diastereoselectivities by three different routes. The first two involved alkylation of the parent α-silylacetic ester enolates, with the chiral auxiliaries being present either on silicon or on the ester function. The third route involving asymmetric insertion of metal-carbenoids into the Si-H band was found to afford better diastereoselectivities, using pantolactane as chiral auxiliary.

N-(chloromethyloxycarbonyl)pyrrolidine as a source of the HOCH2- synthon

The reaction of N-(chloromethyloxycarbonyl)pyrrolidine (1) with lithium powder and a catalytic amount of DTBB (2.5 mol %) in the presence of different electrophiles [Me3SiCl, Bu(i)CHO, Bu(t)CHO, PhCHO, Et2CO, (CH2)5CO, PhCOMe, Ph2CO] in THF at -78°C leads, after hydrolysis with water, to the expected functionalised carbamates 2. Deprotection of the acetophenone derivative 2g with DIBALH at THF reflux yields, after hydrolysis, the corresponding 1,2-diol 3g.

Kinetic resolution of 2-acylated-1,2-diols by lipase-catalyzed enantiomer selective acylation

Enantiomer selectivity of lipase catalyzed acylation of 2-acylated 1,2-diols was studied. First, acylation of 2-acetoxyheptan-1-ol rac-3b with vinyl acetate was investigated by varying the enzymes and the solvent, showing the highest enantiomer selectivity by using lipase from Pseudomonas fluorescens (PfL) in hexane-vinyl acetate (VA). We have found varying or even reversed enantiomer selectivity for different secondary acyl moieties in 2-acyloxyheptan-1-ols rac-3bA-F. Next, all six possible types of enantiomer selective biotransformations (hydrolysis of diacetate and the two kinds of monoacetetes; acylation of diol and the two kinds of monoacetates) were compared on two model diols rac-4b,d. Among the transformations investigated, acetylation of secondary monoacetates rac-3b,d showed the highest enantiomer selectivity. Finally, PfL catalyzed acetylations of several 2-acetylated 1,2-diols rac-3a-g were investigated under our optimum conditions.

SYNTHESIS OF SOME 2'-C-ALKYL DERIVATIVES OF 9-(2-PHOSPHONOMETHOXYETHYL)ADENINE AND RELATED COMPOUNDS

To study the effect of β-substitution in 2'-alkyl derivatives of 9-(2-phosphonomethoxyethyl)adenine (Ia) on the antiviral activity or group specificity, these derivatives were synthesized. 9-(2-Hydroxyalkyl)adenines VIII were prepared by alkylation of adenine with suitably substituted oxiranes XIII or 2-hydroxyalkyl p-toluenesulfonates IV and VI.After protection of the adenine amino group by benzylation (compounds IX) or amidine formation (compounds X), the intermediates were alkylated with bis(2-propyl) p-toluenesulfonyloxymethanephosphonate (XI) in the presence of sodium hydride.After deprotection, the obtained phosphonate diesters XII were converted into phosphoniuc acids I by transsilylation and hydrolysis.This synthetic scheme was used for the preparation of ethyl (Ie), propyl (If), 2-propyl (Ig), 2-methylpropyl (Ih), cyclopropyl (Ii), cyclohexyl (Ij), benzyl (Ik) and phenyl (Il) derivatives.The 2'-trifluoromethyl derivative XXIIa was prepared analogously from 9-(2-hydroxy-3,3,3-trifluoropropyl)adenine (XXa), obtained by alkylation of adenine sodium salt with 2-hydroxy-3,3,3-trifluoropropyl bromide. 2,6-Diaminopurine derivative XXIIb was obtained analogously. 2'-Trimethylsilyl derivative XIXa was obtained by alkylation of adenine with 2-phosphonylmethoxy-3-(4-toluenesulfonyloxy)propyltrimethylsilane (XVII) followed by transsilylation and hydrolysis of diester XVIIIa. 9-(3-Phosphonomethoxybutyl)adenine (XXVIII) and 9-(2-methyl-2-phosphonomethoxypropyl)adenine (XXXV) were prepared from the corresponding hydroxy derivatives XXVIb and XXXII, respectively, by the same reaction pathway as derivatives I.