Skip to main content
Ch. 14 - Ethers, Epoxides, and Thioethers
Wade - Organic Chemistry 9th Edition
Wade9th EditionOrganic ChemistryISBN: 9780135213728Not the one you use?Change textbook
All textbooksWade 9th EditionCh. 14 - Ethers, Epoxides, and ThioethersProblem 54d,e
Chapter 14, Problem 54d,e

One of the crowning achievements of natural products synthesis was Bryostatin 1, published by Professor Gary Keck (University of Utah; Journal of the American Chemical Society, 2011, 133, 744–747). The Bryostatins are a family of compounds isolated from aquatic invertebrates known as Bryozoans. The compounds are of interest for a variety of biological effects, including anti-cancer activity and reversing brain damage in rodents.

(d) How many chiral centers are in this molecule?
(e) Using the number of chiral centers you reported in part (d), calculate the number of stereoisomers possible at these chiral centers. (Ignore stereoisomers at double bonds.)

Verified step by step guidance
1
Step 1: Identify the chiral centers in the molecule. A chiral center is a carbon atom that is bonded to four different groups. Carefully examine the structure of Bryostatin 1 and locate all such carbon atoms. Pay attention to stereochemical indicators such as wedges and dashed bonds, which denote stereochemistry.
Step 2: Count the total number of chiral centers identified in Step 1. Ensure that you do not include carbons in double bonds or carbons that are not bonded to four distinct groups.
Step 3: Recall the formula for calculating the number of stereoisomers possible for a molecule with chiral centers. The formula is \( 2^n \), where \( n \) is the number of chiral centers. This formula accounts for all possible combinations of configurations (R and S) at each chiral center.
Step 4: Substitute the number of chiral centers (from Step 2) into the formula \( 2^n \) to determine the total number of stereoisomers possible for Bryostatin 1.
Step 5: Verify that stereoisomers at double bonds are excluded from the calculation, as stated in the problem. Double-check your work to ensure that only chiral centers are considered in the stereoisomer calculation.

Verified video answer for a similar problem:

This video solution was recommended by our tutors as helpful for the problem above.
Video duration:
2m
Was this helpful?

Key Concepts

Here are the essential concepts you must grasp in order to answer the question correctly.

Chiral Centers

Chiral centers, or stereocenters, are carbon atoms that are bonded to four different substituents, leading to non-superimposable mirror images known as enantiomers. Identifying chiral centers is crucial in organic chemistry as they significantly influence the optical activity and biological properties of molecules. In the context of Bryostatin 1, determining the number of chiral centers is essential for understanding its stereochemistry and potential interactions in biological systems.
Recommended video:
Guided course
05:41
Understanding Other Chiral Atoms

Stereoisomers

Stereoisomers are compounds that have the same molecular formula and connectivity of atoms but differ in the spatial arrangement of their atoms. The number of possible stereoisomers for a molecule can be calculated using the formula 2^n, where n is the number of chiral centers. This concept is vital for predicting the diversity of compounds that can arise from a single structure, such as Bryostatin 1, and their potential biological activities.
Recommended video:
Guided course
01:58
Determining when molecules are stereoisomers.

Optical Activity

Optical activity refers to the ability of chiral compounds to rotate plane-polarized light, a property that arises from the presence of chiral centers. The direction and degree of rotation depend on the specific arrangement of atoms around the chiral center. Understanding optical activity is important in organic chemistry, particularly in the study of natural products like Bryostatin 1, as it can provide insights into the compound's interactions with biological systems and its therapeutic potential.
Recommended video:
Guided course
08:17
Mutorotation and Optical Activity
Related Practice
Textbook Question

Propylene oxide is a chiral molecule. Hydrolysis of propylene oxide gives propylene glycol, another chiral molecule.

(a) Draw the enantiomers of propylene oxide.

(b) Propose a mechanism for the acid-catalyzed hydrolysis of pure (R)-propylene oxide.

2
views
Textbook Question

A compound of molecular formula C8H8O gives the IR and NMR spectra shown here. Propose a structure, and show how it is consistent with the observed absorptions.

<IMAGE>

3
views
Textbook Question

Under the right conditions, the following acid-catalyzed double cyclization proceeds in remarkably good yields. Propose a mechanism. Does this reaction resemble a biological process you have seen? 

1
views
Textbook Question

In 2012, a group led by Professor Masayuki Satake of the University of Tokyo reported the isolation and structure determination of a toxin from a marine algal bloom that decimated the fish population off the New Zealand coast in 1998. Extensive mass spectrometry and NMR experiments ultimately led to the structure shown below, named Brevisulcenal-F. (See Journal of the American Chemical Society, 2012, 134, 4963–4968.) This structure holds the record for the largest number of fused rings, at 17.

(a) How many ether groups are present?

(b) How many alcohol groups are present? Classify the alcohols as 1° or 2° or 3°.

(c) Are there any other oxygen-containing functional groups? Which, if any?