28152-91-2

Upstream product

• 544-97-8 dimethyl zinc(II) 
• 109334-10-3 (4R)-3,4-dimethyl-4-(p-tolyl)-2-cyclopentenone 
• 936723-38-5 (+)-(1R,5R)-4,4-dimethyl-5-p-tolyl-bicyclo[3.1.0]hexan-2-one 
• 515826-81-0 MeCu*BF₃ 
• 124909-15-5 (R)-3,3,4-Trimethyl-4-p-tolyl-hexanedioic acid 
• 124909-14-4 (R)-3,3,4-Trimethyl-4-p-tolyl-hexanedinitrile 
• 124909-13-3 C₂₈H₃₄O₆S₂ 
• 124909-11-1 (S)-2,2,3-Trimethyl-3-p-tolyl-succinic acid dimethyl ester 
• 124909-12-2 (S)-2,2,3-Trimethyl-3-p-tolyl-butane-1,4-diol 
• 109334-07-8 (3S,4S)-2,2-Dichloro-4-methyl-3-((1S,2R)-2-phenyl-cyclohexyloxy)-4-p-tolyl-cyclobutanone 
• 109334-06-7 1-Methyl-4-[(E)-1-methyl-2-((1S,2R)-2-phenyl-cyclohexyloxy)-vinyl]-benzene 
• 109334-05-6 1-Methyl-4-[1-((1S,2R)-2-phenyl-cyclohexyloxymethyl)-vinyl]-benzene 
• 109334-08-9 (R)-2-Chloro-4-methyl-4-p-tolyl-cyclopent-2-enone 
• 40089-09-6 1-(3-chloroprop-1-en-2-yl)-4-methylbenzene 

Relevant academic research and scientific papers

Intramolecular cyclopropanation of unsaturated terminal epoxides and chlorohydrins

Lithium 2,2,6,6-tetramethylpiperidide (LTMP)-induced intramolecular cyclopropanation of unsaturated terminal epoxides provides an efficient and completely stereoselective entry to bicyclo[3.1.0]hexan-2-ols and bicyclo[4.1.0]heptan-2-ols. Further elaboration of C-5 and C-6 stannyl-substituted bicyclo[3.1.0]-hexan-2-ols via Sn-Li exchange/electrophile trapping or Stille coupling generates a range of substituted bicyclic cyclopropanes. An alternative straightforward cyclopropanation protocol using a catalytic amount of 2,2,6,6-tetramethylpiperidine (TMP) allows for a convenient (1 g-7.5 kg) synthesis of bicyclo[3.1.0]-hexan-2-ol and other bicyclic adducts. The synthetic utility of this chemistry has been demonstrated in a concise asymmetric synthesis of (+)-β-cuparenone. The related unsaturated chlorohydrins also undergo intramolecular cyclopropanation via in situ epoxide formation.

Enantioselective synthesis of natural (-)-tochuinyl acetate, (-)-dihydrotochuinyl acetate and (+)-β-cuparenone using both enantiomers of the same building block

The first enantioselective synthesis of tochuinyl acetate and dihydrotochuinyl acetate, two natural marine products isolated from Tochuina tetraquetra and Gersemia rubiformis, has been achieved starting from an enantiopure building block. The key feature of the present synthesis is complete control of two vicinal quaternary stereogenic centers present in the natural products and elucidation of their absolute stereochemistry, which was previously unknown. Furthermore, starting from the enantiomer of the same building block, the applied methodology provided a new approach towards natural (R)-(+)-β-cuparenone.

ENANTIOCONTROLLED SYNTHESES OF THE CUPARENE SESQUITERPENES, (-)-HERBERTENE, (+)-β-CUPARENONE, (-)-DEBROMOAPLYSIN, AND (-)-APLYSIN

Enantiocontrolled syntheses of the Cuparene sesquiterpenes, (-)-herbertene, (+)-cuparenone, (-)-debromoaplysin, and (-)-aplysin, have been achieved starting from the optically active tricyclic dienone by employing a Fischer indolization reaction under non-acidic conditions as the key step.

SYNTHESIS AND UTILIZATION OF OPTICALLY ACTIVE 2-SUBSTITUTED 4-(TRIMETHYLSILYL)CYCLOPENTANONES: SYNTHESIS OF (-)-MASSOIALACTONE AND (+)-β-CUPARENONE

Ring contraction by BF3*Et2O catalyzed epoxide rearrangement of 3-substituted 5-trimethylsilyl-2,3-epoxycyclohexanones gave the corresponding 2-substituted 4-(trimethylsilyl)cyclopentanones diastereoselectively.Synthesis of (-)-massoialactone and (+)-β-cuparenone utilizing the above transformation is also described.

TOTAL SYNTHESIS OF (R)-(-)-β-CUPARENONE

(R)-(-)-β-Cuparenone has been synthesized from (S)-(+)-acid-2 obtained via resolution of the racemic acid.Two of the noteworthy steps are (a) repeated methylation of ester (+)-8 with LDA/MeI to furnish (+)-10 and (b) the reaction of 12, having two neopent