88930-76-1

Upstream product

• 4497-92-1 2-carene 
• 623-73-4 diazoacetic acid ethyl ester 
• 110-93-0 6-Methyl-hept-5-en-2-on 
• 24683-47-4 (1R,3R)-methyl 2,2-dimethyl-3-(3-oxobutyl)cyclopropanecarboxylate 
• 73256-83-4 (+/-)-isobicyclogermacrenol 
• 73256-83-4 (-)-lepidozenol 
• 32543-79-6 (1S,3R)-2,2-dimethyl-3-(3-oxobutyl)cyclopropane-1-carbaldehyde 

Downstream Products

• 4436-81-1 homoterpenylmethylketone 

Relevant academic research and scientific papers

Stereocontrol in Horner-Wadsworth-Emmons Condensations of a gem-Dimethylcyclopropyl Aldehyde with α-Substituted Phosphono Acetates

Oxidative cleavage of 2-carene provides a keto aldehyde attractive as a synthon for terpenoids containing gem-dimethylcyclopropyl rings.However, the sensitivity of this keto aldehyde to intramolekular aldol condensations proscribes the use of many standard conditions for Wadsworth-Horner-Emmons condensations that might be used to extend this carbon skeleton.Through use of dioxolane-containing phosphono acetates and lithium bases, it is possible to obtain olefin derivatives of this keto aldehyde with reasonable selectivity for either E or Z stereochemistry depending on the choice of phosphonate esters.

Efficient syntheses of angularly fused triquinanes via β-amino-substituted α,β-unsaturated fischer-carbene complexes

Formal [3+2] cycloadditions of the carbene ligand in the new (3-dimethylamino-1-alkoxyalkenylidene)pentacarbonylchromium complexes 5 and 14 both with cyclopropyl substituents in the 3-position, onto alkynes give 5-dimethylamino-3-ethoxycyclopentadienes 6 and 15a-f, the latter along with regioisomers 16a-d, in good yields (55-72%). Treatment of these with hydrochloric acid liberates two carbonyl groups in each of them, and the resulting 5-dimethylaminocyclopent-1-en-3-ones 7 and 17a-c/18a-c, under basic conditions, undergo a cascade of two cyclizations, to yield angularly fused triquinanes 10 (68%) and 23a-c (30-97%). The overall procedure consists of four operational steps and produces cyclopropane-annelated tricyclo[6.3.0.01,5]undecane skeletons from two different alkynes each in 22-47% overall yield.

Development of modified Pauson-Khand reactions with ethylene and utilisation in the total synthesis of (+)-taylorione

Two complementary Pauson-Khanol annulation protocols for use with the gaseous alkene, ethylene, are described. These N-oxide promoted reactions (10 examples) are shown to proceed under both mild autoclave condition or, more conveniently, at atmospheric pressure. The developed methodology has been utilised as the key transformation in the total synthesis of the sesquiterpene (+)-taylorione which has been realised in a good overall yield from readily available (+)-2-carene.

Structures and Conformations of (-)-Isobicyclogermacrenal and (-)-Lepidozenal, Two Key Sesquiterpenoids of the cis- and trans-10,3-Bicyclic Ring Systems, from the Liverwort Lepidozia vitrea: X-Ray Crystal Structure Analysis of the Hydroxy Derivative of (-)-Isobicyclogermacrenal

The structures and absolute configurations of the two sesquiterpene aldehydes, (-)-isobicyclogermacrenal (1) and (-)-lepidozenal (2), which were isolated from the liverwort Lepidozia vitrea, have been determined on the basis of chemical and spectroscopic evidence to be (6R,7S)-6,11-cyclogermacra-1(10)E,4E-dien-14-al and (6R,7R)-lepidoza-1(10)E,4E-dien-14-al, cosisting of the cis- and trans-10,3-bicyclic ring systems.The structure of the former (1) has been confirmed by a single-crystal X-ray analysis of its hydroxy derivative (7).The molecular conformations, biogenetical features, and biological activity are also described.

(-)-LEPIDOZENAL, A SESQUITERPENOID WITH A NOVEL TRANS-FUSED BICYCLOUNDECANE SYSTEM FROM THE LIVERWORT LEPIDOZIA VITREA

A sesquiterpene aldehyde, (-)-lepidozenal, having a novel trans-fused bicycloundecane carbon skeleton has been isolated from the liverwort Lepidozia vitrea, and its structure and absolute configuration have been shown to be (6S,7R)-lepidoza-1(10)E,4E-dien-14-al, on the basis of the chemical and spectral evidence.