S. C. Bhattacharyya

Terpenoids-XXXIV: structure and stereochemistry of zingiberol and juniper camphor

Zingiberol has been shown to be a stereoisomeric mixture of β-eudesmol with trans- and cis-ring juncture. This has been established by the comparative chemical and NMR studies of zingiberol, juniper camphor and β-eudesmol. Juniper camphor has been found to possess a cis-ring juncture.

13C NMR spectra of some furocoumarins

Abstract 13 C NMR spectra of some naturally occurring furocoumarins and derivatives have been examined. The assignment of chemical shifts for all the C atoms has been achieved by using techniques recently reported by Bose et al.

Terpenoids—XXXI : Isolation of humulene monoxide and humulene dioxide

Two new oxygenated derivatives of humulene, viz., humulene monoxide (II) and humulene dioxide (VIII) have been isolated from the sesquiterpene fractions of wild ginger oil (Zingiber zerumbet, Smith). The structures of these two epoxides have been determined by degradative and synthetic studies.

Terpenoids—xl : The structure and absolute configuration of khusol☆

Abstract Khusol, a crystalline primary sesquiterpene alcohol, C 15 H 24 O, isolated from North Indian vetiver oil has been assigned the structure and absolute configuration represented by I. It belongs to the antipodal group of cadinenic alcohols.

Terpenoids—XXXVIII : Structure and stereochemistry of (−)γ2-cadinene☆

Abstract A new sesquiterpene hydrocarbon, (−)γ 2 -cadinene, has been isolated from Indian vetiver oil. On the basis of formation of (+) cadinene dihydrochloride and other reactions, its structure and absolute configuration are represented by the formula I. It belongs to the unusual antipodal group of cadinenes.

Terpenoids-LXXXVI: structure of epi-Ψ-taraxastanonol and epi-Ψ-taraxastanediol

Abstract Two new pentacyclic triterpenes of the taraxastane group have beenisolated from Canarium strictum Roxb. One is a ketol and the other a diol. Chemical evidence, IR, UV, NMR spectra and their mass spectral disintegration patterns show that they are represented by the structures I and IIa. They have been named as epi-ψ-taraxastanonol and epi-ψ taraxastane diol respectively.

Terpenoids—LXXVI : Transformation products from BF3-catalysed reaction of khusinol

Abstract On the basis of chemical and spectral evidence, the structure II and the absolute configuration XII are assigned to khusinodiol, the principal component obtained by BF 3 -ethereate treatment of khusinol (III). The hydrocarbon obtained as a minor product during this reaction has the structure I. Diene monol (XIII), (+)-α-cadinol (XIV) and iso-khusinol (XI) have also been prepared starting from khusinodiol.

Terpenoids-LIII: structure of khusilal, a novel aldehyde from vetiver oil

North Indian vetiver oil yielded a new laevorotatory aldehyde khusilal, C14H18O. Structure II has been assigned to it on the basis of UV, IR and NMR spectra and chemical evidence.

Terpenoids—XCIX: Structure and absolute configuration of khusinoloxide, a new antipodal sesquiterpene epoxy alcohol from vetiver oil

Abstract A new laevorotatory epoxy alcohol, khusinoloxide, C15H24O2, has been isolated from North Indian vetiver oil (Vetiveria zizanioides, Linn). Structure I has been assigned to it on the basis of IR and NMR spectra and its correlation with khusinol (II), of known absolute configuration. Khusinoloxide also belongs to the antipodal group of cadinenes.

Intramolecular O–H ⋯π interaction studies in homoallyl alcohols

Some acyclic, mono- and bi-cyclic homoallyl alcohols exhibit bands due to more than one type of bonded species in the O–H stretching region, which have been assigned to specific bonded conformations.