Explore BrainMass

Stereochemistry, Bonding and Formation

Organic Chemistry

1. The compound 2-methyl-1,4-pentadiene would be classified as what type of diene? a. conjugated b. isolated c. cumulated d. internal 2. Select the least stable diene listed below: a. 2,3-pentadiene b. trans-1,3-pentadiene c. cis-1,3-pentadiene d. 1,4-pentadiene 3. Whic

Conjugation in Alkadienes & Allylic Systems

What are the differences between vinylic & allylic hydrogens in a Cyclohexene (ie. how many of each, what determines it)? Second, what is the best way to determine a conjugated diene? Are there any rules? In 1,1-dimethylallyl the cation is positive: which type of carbon is that, tertiary? In 1,3-butadiene is the act

Splitting pattern predictions

Help required for predicting the splitting patterns expected for each proton (proton 1 and proton 2) in 2,3-dimethylbutane. What is the number of adjacent hydrogens and what are the splitting patterns?

13C NMR spectral data

I need help with matching the spectral data to the correct structures. Please see attachment.

Stereochemistry of Anthracene and Polycyclic Benzenoid

I need some help with these two questions on stereochemistry, bonding and formation. 1. There are four reasonable resonance structures for anthracene. Draw them. 2. A large number of polycyclic benzenoid aromatic hydrocarbons are known. One of these, benz/a/pyrene, is a powerful carcinogen found in tobacco smoke. From the

Treatment of one stereoisomer of 2-iodo-3-phenylbutane

PROBLEM: Treatment of one stereoisomer of (2 ?, 3R)-2-iodo-3-phenylbutane with base, yields (E)-2-phenylbutene. a) Determine which enantiomer of 2-iodo-3-phenylbutene gives the E product (2R, 3R or 2S, 3R), and explain clearly (using unambiguous diagrams) why that is the case. b) Assign that enantiomer as either R or


Stereoisomers in organic chemistry. See attached file for full problem description.


Please see attached... I chose there are a total of 2 steroisomers and both are optically active

Fischer projections

9. a. Using Fischer projections, draw all the possible stereoisomers 2, 4-dihydroxybutane (CH3-CHOH-CHOH-CH3) b. Label the relationships of your answers in "A" as enantiomers, diastereomers, or Meso ( if any) c. Assign absolute configurations to the chiral carbons n one of your Fischer projections. d. Indicate which of the

Match the structures below with the best description of the type of alkyl halide... See attached Provide structures of products for the following reactions. Include 3-dimensional stereochemistry and absolute configurations where appropriate. If more than one product is possible, circle that which is predominant.

Organic Chemistry - Chlorination of Propane

The chlorination of propane yields 4 different dichloropropanes of formula C3H6Cl2. Using the following information to identify dichloropropanes A,B,C,D. i. If each dichloropropane is further chlorinated to yield trichloropropanes. Compound A gave one trichloropropane, B gave two, C and D each gave three. ii. Dichloropropane D

Enantiomer of cis-1-chloro-3-methylcyclopentane

Draw the enantiomer of cis-1-chloro-3-methylcyclopentane which is R at C-1. 1) What is the configuration of this molecule at C-3 (R and S)? 2) When cis-1-chloro-3-methylcyclopentane and trans-1-chloro-3-methylcyclopentane are treated with sodium iodide in aqueous acetone, their rates of substitution are strikingly differ

Organic products

"Draw the structure of the major organic product of each of the following four reactions (one in the first file, two in the second file). Indicate stereochemistry if appropriate." Please see the attached files.

2-methyl 1-pentene

Consider the bromination of the compound 2-methyl 1-pentene in the attached file. 1. write the basic structure of the product of the bromination of 2-methyl 1-pentene, without regard to stereochemistry. 2. Does the product have any chiral carbons? If so, identify them with an circle. 3. How many stereoisomers are for

Tetrapeptides of 2 alanine & 2 valine

How many different tetrapeptides containing 2 molecules of alanine and 2 molecules of valine could theoretically exist? What are they? Write in shorthand.

Drawing Compound Structures

Draw the structure for: a) 4-methyl-2-chloro pentanal b) trans-3-chloro-2-fluoro cyclopentanone c) 3,5-dipropyl benzaldehyde d) 1,3 cycloheptadione

Molecular formula, structures, and functional groups

On the attached pages are the combined IR, 1H NMR and 13C NMR for Problems 1 and 2. Systematically solve the structure for each one. Provide the structure in the space attached, also, fill in the information requested on the table attached. Thank you!

HBr addition to a diene

I am trying to come up with a structure for a conjugated diene that would give the same product when HBr is added in either a 1,2-addition or in a 1,4-addition.

Forming C5H9Br

When 1-pentene reacts with N-bromosuccinimide, two products with the formula C5H9Br are obtained. What are these products and how are they formed?

Identifying Structures from Spectra

Please identify the structure giving the following spectra (NMW, IR, Mass Spec, etc.) (attached) and state how you arrived at your structure (give reasons such as peak identifcation and mass, etc.).

Products attached to C3, etc.

I attempted some of this but I am clueless as to some of the other stuff. Can you help? 2) Why are the products attached to C3 of 1,4 pentadiene more acidic than the methyl hydrogen atoms of propene? Maybe you can help me with this one. Are the C3 atoms more acidic because there is more s character involved with the ato