133383-81-0

Basic information

• Product Name: Benzene, [bromo(2,2,5,5-tetramethylcyclopentylidene)methyl]-
• CAS NO: 133383-81-0
• Molecular Formula: C16H21Br
• Molecular Weight: 293.247
• Mol File: 133383-81-0.mol

Chemical Properties

• CAS DataBase Reference: Benzene, [bromo(2,2,5,5-tetramethylcyclopentylidene)methyl]-(CAS DataBase Reference)
• NIST Chemistry Reference: Benzene, [bromo(2,2,5,5-tetramethylcyclopentylidene)methyl]-(133383-81-0)
• EPA Substance Registry System: Benzene, [bromo(2,2,5,5-tetramethylcyclopentylidene)methyl]-(133383-81-0)

Safety Data

• Hazardous Substances Data: 133383-81-0(Hazardous Substances Data)

Upstream product

• 54462-71-4 2,5-dibromo-2,5-dimethyl-hexane 
• 536-74-3 phenylacetylene 
• 133383-86-5 2-benzoyl-1,1,3,3-tetramethylcyclopentane 

Downstream Products

• 133383-86-5 2-benzoyl-1,1,3,3-tetramethylcyclopentane 
• 661-69-8 hexamethyldistannane 

Relevant articles and documents

Microsolvation, aggregation, and pseudomonomolecular, ionic sp 2-stereoinversion mechanism of two exocyclic β,β-di-tert- alkyl-α-arylvinyllithiums This article is dedicated to Professor Paul Knochel in recognition of his kind support.

A THF-solvated, crystalline, exocyclic alkenyllithium, (tert-alkyl) 2CC(Li)-Ph, was synthesized and shown to be a disolvated dimer in the solid state and in toluene as the solvent; increasing amounts of the monomeric species emerged on cooling the toluene solution. In THF as the solvent, only the trisolvated monomer was present and identified as a contact ion pair (CIP) through its scalar 13C,6Li NMR coupling. This ground-state needs only one further THF ligand as a catalyst for breaking the C-Li bond with formation of a tetrasolvated, solvent-separated ion pair (SSIP) on the way to the transition state of cis/trans sp2-stereoinversion. The ensuing pseudomonomolecular, ionic mechanism is confirmed by low pseudoactivation parameters: enthalpy ΔHψ? = 6.9(3) kcal mol-1; entropy ΔSψ? = -23.3(9) cal mol-1 K-1. Similar parameters were found with 2,6-dimethylphenyl in place of Ph.

Aluminium-mediated [4 + 1] cyclization reaction: Novel synthesis of 2,2,5,5-tetramethylcyclopentanecarboxylic acid

A new [4 + 1] cyclization reaction mediated by aluminium is developed and applied to the synthesis of 2,2,5,5-tetramethylcyclopentanecarboxylic acid, a part of an artificial sweetner.