New approach towards carotane sesquiterpenes: a short synthesis of (-)-daucene

An enantioselective synthesis of sesqui-terpene hydrocarbon (-)-daucene 1 from R-(+)-limonene involving acid catalysed enone- olefln cyclisation (5 ° 6) as the key step is described

Restructuring α -pinene: novel entry into diverse polycarbocyclic frameworks

(-)-α-Pinene 1 has been restructured into a chiral cyclohexenone (+)-6, in which the functionalities were integrated to afford bicyclo[3.3.1]nonan 3,7-diones and a novel tricyclic skeleton 16 related to the sesquiterpene clovene. Intramolecular [2+2] photocycloadditions in (+)-6 and related 5-alkenylcyclohexenones provided an entry into some novel bridged tricyclic systems

Oxa-bowls: formation of exceptionally stable diozonides with novel, C-H···o hydrogen bond directed, solid state architecture

Several tetraquinane-based diolefins on ozonization furnish unusually stable diozonides of 'bowl-like' topology and their solid state structure reveals interesting architecture woven through a network of unique C-H···O interactions

Total synthesis of the novel tricyclic sesquiterpene sulcatine G

A synthetic approach to the tricyclic sesquiterpene sulcatine G, 2, bearing a novel tricyclo[6.2.0.02,6]decane framework, from commercially available 1,5-cod and leading to the first total synthesis of the natural product is described

Novel tandem ring-opening/ring-closing metathesis reactions of functionalized cyclohexenoids derived from (-)-α-pinene

The cyclohexenone (+)-2, readily obtained from (-)-α -pinene 1 was elaborated to (+)-3 in an attempt to construct the AB rings of taxoids employing the ring-closure metathesis (RCM) reaction as the key step. In the event, a novel ring-opening/ring-closing metathesis reaction was encountered in the relatively strain free cyclohexenyl ring of (+)-3

Baeyer-Villiger oxidation of norbornan-7-ones: long-range substituent effects on regioselectivity

The regioselectivity of the Baeyer-Villiger oxidation of norbornan-7-ones can be steered by the distal 2-endo-substituents present. Hydrolysis of the resulting bicyclic lactones provides a stereospecific route to functionalized cyclohexanes

Longifolene as a chiron: extraction of the bicyclic core of the spongian-type diterpenoids

A short degradation of (+)-longifolene 1 to hydroazulene (+)-9 is described. Restructuring of 1 to a novel tricyclic framework (-)-10 is also reported

A norbornyl route to azasugars: stereoselective synthesis of isofagomine analogues

A stereoselective synthesis of new isofagomine analogues has been achieved from a suitably functionalized cyclopentene intermediate extracted from the norbornyl framework. Double reductive amination or inter- and intramolecular N-alkylations are the key steps in constructing the piperidine ring. Isofagomine derivatives exhibit moderate inhibitory activity in enzyme assays

Enantioselective total synthesis of (-)-epoxyquinols A and B. Novel, convenient access to chiral epoxyquinone building blocks through enzymatic desymmetrization

Following our recent total synthesis of the biologically potent natural products epoxyquinols A and B in racemic form, we have now accomplished the total synthesis of the (-)-epoxyquinols A and B, anti-podes of the angiogenesis inhibiting natural products, through a protocol that involves enzymatic desymmetrization of a versatile epoxyquinone derivative, readily available from the Diels-Alder adduct of cyclopentadiene and p-benzoquinone

A synthesis of Indan-based primnatriene sesquiterpene skeleton

A synthesis of densely substituted indane skeleton present in primnatriene sesquiterpenes has been accomplished in a short sequence in which a regioselective Haller-Bauer cleavage of endo-tricyclo[5.2.1.2,6]dec-8-en-3, 10-dione 3 serves as the key step