Indian Journal of Chemistry

Sect. B. Organic Chemistry including Medicinal Chemistry

VOL. 41B

NUMBER 5

MAY 2002

CONTENTS

 

Rapid Communications

 

 

1012

Regio- and stereoselective synthesis of isoxazolines via cycloaddition reactions using pregnenolone as chiral auxiliary

Asymmetric synthesis of 3-phenyl-5-(R)-(hydroxy-methyl)-2-isoxazoline has been achieved in good yield via 1,3-dipolar cycloaddition reaction of nitrile oxide with pregnenolone acrylate.

 

 

 

 

Utpal Sharma, Utpal Bora, Apurba Chetia, Romesh C Boruah* & Jagir S Sandhu

 

 

 

 

 

 

 

Papers

 

 

1015

A short and enantioselective synthesis of N-terminal components of bestatin, amastatin and microginin

 

 

 

 

 

Prodeep Phukan

 

 

 

 

 

 

 

 

 

 

1019

3-Trimethylsilylbicyclo[3.2.1]oct-2-ene in the synthesis of functionalized bicyclo[3.2.1]octane systems

 

 

 

 

Govindagouda S Patil &Gopalpur Nagendrappa*

 

 

 

 

 

 

 

 

 

1025

Lipase catalyzed esterification of free hydroxyl groups of b-cyclodextrin and its derivatives

Modification of hydroxyl groups of b-cyclodextrin and its methyl and hydroxyl derivatives through lipase catalyzed reaction using Rhizomucor miehi lipase in n-heptane at 50oC has been carried out and extent of esterification determined by 1H NMR is discussed.

 

H H Pattekhan & S Divakar*

 

 

 

 

 

 

 

1028

Coupling in the absence of tertiary base : A method for the deprotonation of hydrochloride salts of peptide esters to free amino peptide esters

 

    Y = OMe or OEt

 

 

Subramanyam J Tantry, K Ananda &
V V Suresh Babu*

 

 

 

 

 

 

 

1032

Microwave promoted selective preparation of acetals and esters from aldehydes

 

 

Ruli Borah, Dipok J Kalita & Jadab C Sarma*

 

 

 

 

 

 

 

1039

Kinetic studies on oxidation of Gly-Val-Gly, Gly-Phe-Gly and Ala-Val-Gly using Mn(III)

Fragments of human elastin sequences GVG,GFG and AVG have been synthesized and subjected to kinetics of oxidation with Mn(III). A first order dependence of rate on both [Mn(III)] and [TP] is observed. A tentative mechanism involving the reaction of tripeptide with Mn(III) in the rate limiting step is suggested.

 

B K Kempe Gowda, K S Rangappa &
D Channe Gowda*

 

 

 

 

 

 

 

 

1045

Kinetics and mechanism of the ninhydrin reaction with nickel(II)-tryptophan complex in aqueous and aqueous-micellar solutions

 

 

 


Kabir-ud-Din*, Mohd Akram & Zaheer Khan

Effect of micelles on the reaction rate of ninhydrin with [Ni(II)-trip]+ complex has been stuied.

 

 

 

 

 

 

1052

Synthesis of the prodrug ibuprofen b-d-gluco-pyranoside and its biological evaluation as a better moiety than the parent drug

Ibuprofen b-d-glucopyranoside, the prodrug of ibuprofen has been synthesised. It shows better anti-inflammatory and analgesic activity and a lesser gastrointestinal toxicity in comparison to ibuprofen.

 






M S Y Khan* & R M Khan

 

 

 

 

 

 

1056

Synthesis and termiticidal activity of pyrazolo-pyrimidine derivatives: N1-nicotinoyl-4'-(sulpha/ substituted phenylazo)-1,2-diazole-4,6-dimethyl-pyrimidin-5–one

A novel series of fused heterocycle pyrazolopyrimidine namely N1-nicotinoyl-4'-(sulpha/substituted phenylazo)- 1,2-diazole-4,6-dimethylpyrimidin-5-one has been synthesised by condensation of sulpha/substituted phenylazo-1,3-dimethyl-2,4,6-pyrimidine trione with nicotinic acid hydrazide. The compounds have been screened for termiticidal activity. A few compounds have shown excellent activity against termites (Odentotermes obesus).

 

Y Singh*, S S Nayal, B S Rawat & Mahesh Pal

 

 

 

 

 

 

 

1061

New long chain alcohol and ester from Papaver somn ferum (Poppy) seeds

Two new compounds, methyl (19Z)-pentacosenoate and 8-heptacosanol have been isolated from the seeds of Papaver somniferum and characterised by spectral analysis.

1                                             

2                                             

 

S K Agarwal*, Sushma Verma, Sudhir S Singh & Sushil Kumar

 

 

 

 

 

 

 

 

Notes

 

 

 

 

 

 

1064

Removal of some commonly used protecting groups in peptide syntheses by catalytic transfer hydrogenation with formic acid and 10% palladium on carbon

Formic acid, a good solvent for most peptides, is used as a convenient hydrogen donor for catalytic transfer hydrogenation with 10% Pd-C for the removal of some commonly used protecting groups in peptide synthesis is described.

 

Xaa = amino acid or peptide derivative

Y = Z, 2-ClZ, Bom, Obzl or NO2

 

D Channe Gowda*

 

 

 

 

 

 

 

1068

Lipase catalyzed esterification of cresols

Lipase catalysed synthesis of m- and p-cresol esters with organic acids of carbon chain lengths C2-C18 has been carried out.

 

 

C V Suresh Babu, N G Karanth & S Divakar*

 

 

 

 

 

1072

Reduction of oximes with sodium borohydride - copper (II) sulfate in methanol

Reduction of aldoximes and ketoximes with sodium borohydride in methanol reflux results in corresponding primary and secondary amines in good yields.

 

 

 

 

H Surya Prakash Rao* & B Bharathi

 

 

 

 

 

 

 

1075

Fischer cyclization over molecular sieves in presence of microwave irradiation

 

 

M Radha Kishan, N Srinivas, S J Kulkarni* & K V Raghavan

 

 

 

 

 

 

 

 

1078

Pinacol coupling of aromatic aldehydes & ketones using Zn-ZnCl2 under ultrasound

The coupling reaction of aromatic aldehydes and ketones leading to pinacols has been carried out using Zn-ZnCl2 in 50% aq. THF under ultrasound in 5-77% yield.

 

 

 

 

 

 

Hong-Jun Zang, Ji-Tai Li*, Ning Ning, Na Wei & Tong-Shuang Li

 

 

 

 

 

 

 

1081

Environmentally safe and facile solid state regeneration of carbonyl compounds from oximes by silica supported MnO2 under microwave irradiation

An efficient method for solvent free “dry” state conversion of oximes to corresponding carbonyl compounds using silica supported MnO2 under microwave irradiation is reported. The deoximation has been tested for at least twelve runs with just air drying the reagent after each run and with reproducible yields.

 

 

 

 

 

 

Bhushan M Khadilkar* & Virendra R Madyar

 

 

 

 

 

 

 

1083

Protection of amino group as N-phthalyl derivative using microwave irradiation

The amino groups for various substrates have been protected as N-phthalyl derivatives using solvent free neat condition under microwave exposure.

 

 

 

 

Bhushan M Khadilkar* & Virendra R Madyar

 

 

 

 

 

 

 

 

1086

Enamine derivatives of 1,2,3,4-tetrahydro-7,8-dimethoxy-1-p-tosyl-1-benzazepin-5-one as potential antiinflammatory agents

1, 2, 3, 4-Tetrahydro-7, 8-dimethoxy-1-p-tosyl-1-benzazepines 2-4 have been prepared by reacting 1  with secondary amines.

 

 

Lingaiah Nagarapu* & N Venkateswara Rao

 

 

 

 

 

 

 

1088

Novel diterpenoids and aliphatic compounds from Thuja orientalis

Two diterpenoids 1 and 2 of labdane group and five long chain aliphatic compounds have been isolated from the hexane extract of leaves of Thuja orientalis. The compounds have been identified on the basis of spectral and chemical evidences.

 

B K Mehta*, Vibha Nagar, Satish Shitut,
Sanjay Nagar & Sanjay Sharma

 

 

 

 

 

 

 

1093

Secondary metabolites from the Gorgonian Echinomuraceae splendens (Thomson & Simpson)

Two xanthine derivatives, caffeine (1,3,7-trimethyl-xanthine 1) and its 2-O-methyl analog 2, N-methylpyrazole-5-carboxylic acid 3 and a tetrahydroxysterol, 1b, 3b, 5a, 6b-tetrahydro-xycholes-ane 4 have been isolated from the methanol extract of the Gorgonian Echinomuraceae splendens.

 

P S Parameswaran*, C G Naik, M Govenkar
& V R Hegde

 

 

 

 

 

 

 

 

 

1099

Isolation of 3b-hydroxyolean-12-ene, friedelin and 7-methoxy-4¢-5-dihydroxyisoflavone from dry and fresh leaves of Shorea robusta

The 3b-hydroxyolean and related triterpenoids from the petroleum extract of dry leaves and an isoflavone have been isolated from the acetone extract of the fresh leaves of Shorea robusta.

 

 

 

S M S Chauhan*, Mamta Singh &
Luxmi Narayan

 

 

 

 

 

 

 

 

 

 

 

1100

Additions and Corrections

 

 

 

 

 

 

Authors for correspondence are indicated by (*)