Halogenated terpenoids. II. The 1,8-Dihalo-p-menthanes

Carman, RM; Deeth, HC

doi:10.1071/ch9692651

Cited by 4 publications

(2 citation statements)

References 0 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The reaction of ( R )‐(+)‐limonene produced a 4.5:1 mixture of two dichlorides (entry 9). The predominant product was the more stable conformer with axial chlorine 22. Both α‐pinene and β‐pinene furnished the same product mixture, consisting of limonene hydrochloride , endo ‐2‐chloro‐1,7,7‐trimethylbicyclo[2.2.1]heptane and endo ‐2‐chloro‐1,3,3‐trimethylbicyclo[2.2.1]heptane.…”

Section: Resultsmentioning

confidence: 99%

A Remarkably Efficient Markovnikov Hydrochlorination of Olefins and Transformation of Nitriles into Imidates by Use of AcCl and an Alcohol

Yadav

Babu

2005

Eur J Org Chem

View full text Add to dashboard Cite

HCl generated by mixing AcCl with EtOH brings about Markovnikov hydrochlorination of olefins in excellent yields. The products are isolated in states of high purity simply by removal of the volatile components under reduced pressure. Further, nitriles are transformed into imidate hydrochlorides on similar treatment with AcCl and an alcohol. This procedure for nitrile‐imidate transformation is much more efficient than that used previously, which involved continuous passing of HCl gas into the solution of a nitrile in a solvent such as Et2O or benzene and an alcohol until one equivalent had been absorbed. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2005)

show abstract

Section: Resultsmentioning

confidence: 99%

A Remarkably Efficient Markovnikov Hydrochlorination of Olefins and Transformation of Nitriles into Imidates by Use of AcCl and an Alcohol

Yadav

Babu

2005

Eur J Org Chem

View full text Add to dashboard Cite

show abstract

“…Recycling of limonene dihydrochloride would only further increase atom economy, contributing to a more efficient reaction and reducing the amount of waste produced. A number of dehydrochlorination methods have been reported in the literature . The unsaturated terpene formed, can eventually be reapplied in the leucine-NCA synthesis.…”

Section: Optimization Of the Reaction Systemmentioning

confidence: 99%

A Scalable Synthesis of l-Leucine-N-carboxyanhydride

Smeets

Weide

Meuldijk

et al. 2005

Org. Process Res. Dev.

View full text Add to dashboard Cite

Due to its relevance in the synthesis of well-defined oligopeptides, the L-leucine-N-carboxyanhydride (leucine-NCA) synthesis was selected for fine chemical scale-up with a scope on application on larger scales. The heterogeneous gas-solidliquid nature of the leucine-NCA synthesis implied a mass transfer limited reaction rate towards phosgenation and was investigated on bench scale. Upon scale increase, the liquidgas mass transport of HCl is drastically reduced, retarding the reaction and consequently rendering the process unsuitable for scale-up. Addition of an HCl scavenger such as (+)-limonene prevented side reactions thus allowing a cost reduction, a considerably faster reaction, and minimization of the amount of phosgene source used. The modified leucine-NCA synthesis has successfully been made scalable, maintaining high product purity on a 1.0 dm 3 scale.

show abstract