88948-25-8

Upstream product

• 88941-07-5 (1S,2R,3S)-3-(2,2-dimethylpropoxy)-4,7,7-trimethylbicyclo<2.2.1>hept-2-yl (1S,2S)-3-methylidene-2-(4-methyl-3-pentenyl)bicyclo<2.2.1>heptane-2-carboxylate 
• 85695-96-1 (1R,2S,3R,4S)-2-(2,2-dimethylpropoxy)-1,7,7-trimethylbicyclo<2.2.1>heptan-3-ol 
• 630-17-1 2,2-dimethylpropyl bromide 
• 88948-24-7 (1S,2R,3S)-3-(2,2-dimethylpropoxy)-4,7,7-trimethylbicyclo<2.2.1>hept-2-yl bromoacetate 
• 603-35-0 triphenylphosphine 
• 25763-72-8 (1R,2S,4S)-(-)-3,3-ethylenedioxy-1,7,7-trimethylbicyclo[2.2.1]heptan-2-ol 
• 106618-21-7 (1S,3S)-3-(2,2-dimethylpropoxy)-4,7,7-trimethylbicyclo<2.2.1>heptan-2-one 
• 106618-20-6 (1R,2S)-3,3-ethylenedioxy-2-(2,2-dimethylpropoxy)-1,7,7-trimethylbicyclo<2.2.1>heptane 
• 23963-14-6 (1S,4R)-4,7,7-trimethylspiro[bicyclo[2.2.1]heptane-2,2'-[1,3]dioxolan]-3-one 

Relevant academic research and scientific papers

221. Asymmetric Diels-Alder Reactions of Neopentyl-Ether-Shielded Acrylates and Allenic Esters: Syntheses of (-)-Norbornenone and (-)-β-Santalene

Starting from (+)- or (-)-camphor, the antipodal alcohols 14 and 18, respectively, have been prepared; the corresponding acrylates 15 and 19 underwent TiCl2(i-PrO)2-mediated Diels-Alder additions to cyclopentadiene to give adducts 20a and 22a respectively, with 95percent endo- and 99.2percent ?-face selectivities.Adduct 22a was converted to enentiomerically pure norbornenone 26.Addition of 1,3-butadiene to acrylate 15 in the presence of TiCl4 afforded 3-cyclohexenyl carboxylate 29 with > 95.6percent stereodifferentiation.The TiCl2(i-PrO)2-promoted cycloaddition of cyclopentadiene to allenic ester 43 proceeding with 99percent face differentiation served as the key step for an efficient enantioselective synthesis of (-)-β-santalene ((-)-41) with concomitant recovery of the chiral control alcohol 14.

ASYMMETRIC DIELS-ALDER REACTION OF A CHIRAL ALLENIC ESTER: ENANTIOSELECTIVE SYNTHESIS OF (-)-β-SANTALENE

The Lewis-acid promoted Diels-Alder reaction of the allenic ester 10 provides the adduct 11 with excellent ?-facial selection leading to an efficient enantioselective synthesis of (-)-β-santalene and to the recovery of the chiral control element 7.