Effectiveness of a 2-Cycle Organic

Chemistry SequenceDoug Schirch

BCCE, August 2010

2-Cycle Organic Chemistry

• Covers material from a standard 2-semester course in a different sequence:– First semester: Survey course of the fundamentals

of organic chemistry (functional groups, nomenclature, major reactions, etc.)

– Second semester: Builds on top of the first semester, more in-depth coverage, more rigorous.

Problems with Standard Sequence

• 1-semester students (Biology and Environmental Science majors; 40%) – Miss many functional groups common in nature

(carboxylic acids, amides, esters, amines, etc.)– Forced to learn less relevant material

• All students: often can’t see the forest for the trees.

• Small schools can’t offer separate courses

With 2-Cycle Sequence

• 1-semester students:– Get a survey of the most pertinent organic

chemistry.

• 2-semester students (Chem. majors and pre-professionals) :– Build a solid foundation in basic organic chemistry

before engaging more advanced material.– In 2nd semester, forced to recall 1st semester

material to build on it, resulting in better learning.

Outline

1. Background2. Course content in each semester3. My experiences4. Results of standardized final exams before

and after adopting a 2-cycle approach5. Student opinions.

Background

• Previous publications:– Minter and Reinecke. J of Chem Ed. (1985), Vol. 62• At Texas Christian Univ.

– Sartoris. J of Chem Ed. (1992), Vol. 69• At Wittenberg Univ.

– Gravert. J of Chem Ed. (2006), Vol. 83• At St. Mary’s University of Minnesota

• All 3 reported higher ACS scores after adopting 2-cycle approach

• Material covered in 1st and 2nd semesters …• Textbook options– 1st: Survey text, then 2nd: 2-semester text– 2-semester text used both semesters– [Interested in a text for 2-cycle approach?]

• Number of schools using this approach?

Sequence I Use1st Semester 2nd Semester

Review of bonding theories, EN, etc.

Const. and geometric isomers, conformers, intro to chirality

Intro. to all the major functional groups, their nomenclature, and properties

Fundamental reactions for each functional group

Limited mechanisms

Some multi-step synthesis problems

Lab: Standard purification techniques, TLC, melting points, a synthesis, GC-MS

Sequence I Use1st Semester 2nd Semester

Review of bonding theories, EN, etc. Additional reactions

Const. and geometric isomers, conformers, intro to chirality

Additional mechanisms

Intro. to all the major functional groups, their nomenclature, and properties

More depth on nucleophilic substitution and chirality

Fundamental reactions for each functional group

More complex multi-step synthesis problems

Limited mechanisms Spectroscopy

Some multi-step synthesis problems

Lab: Standard purification techniques, TLC, melting points, a synthesis, GC-MS

Lab: Syntheses, literature project, qualitative analysis using MS, FT-NMR, FT-IR

My experiences: what worked, what didn’t

• Textbook: 2-semester Carey for both semesters

• Homework: – Submitted more frequently, but– Insufficient problems in 1st semester sometimes

• In 2nd semester students are stronger, better prepared, and have better study skills

• Weekly help sessions no longer needed• Problematic for transfers (?)

Comparison of Scores on Standardized Final Exam at End of 2nd Semester

Standard sequence

2-cycle sequence

Comparison of Scores on Standardized Final Exam at End of 2nd Semester

Standard sequence

2-cycle sequence

Survey of Student Perceptions

• Survey sent to all previous students from the years a 2-cycle sequence used.

–Of 31 one-semester students, 17 (55%) responded

–Of 49 two-semester students, 30 (61%) responded

• “I think it was good to have the first semester of the course be a general survey of organic chemistry that covers the fundamental topics relevant to biology.”

1-semester students

2-semester students

Strongly Disagree 1 6% 0

Disagree 0 0

Neither agree nor disagree

0 2 7%

Agree 6 35% 15 50%

Strongly Agree 10 59% 13 43%

• “I found it confusing to be skipping some chapters or sections in the textbook.”

1-semester students

2-semester students

Strongly Disagree 3 18% 7 23%

Disagree 11 65% 18 60%

Neither agree nor disagree

2 12% 3 10%

Agree 1 6% 2 7%

Strongly Agree 0 0

• “I think it would be better to follow the standard sequence, going through the first half of the text in the first semester and the second half of the text in the second semester..”

1-semester students

2-semester students

Strongly Disagree 3 18% 8 27%

Disagree 11 65% 15 50%

Neither agree nor disagree

2 12% 7 23%

Agree 1 6% 0

Strongly Agree 0 0

• “For the content we covered in the first semester, I think I would have learned better with a smaller textbook designed for a 1-semester introduction to organic chemistry course, instead of the larger 2-semester text that we used parts of.”

1-semester students

Strongly Disagree 1 6%

Disagree 7 41%

Neither agree nor disagree

6 35%

Agree 3 18%

Strongly Agree 0

• “Instead of the large 2-semester text that we used for both semesters, I think I would have learned better with a smaller textbook designed for a 1-semester introduction to organic chemistry course in the first semester, and then only using the larger 2-semester text for the second semester.”

2-semester students

Strongly Disagree 5 17%

Disagree 11 37%

Neither agree nor disagree

7 23%

Agree 7 23%

Strongly Agree 0

• “Seeing some material twice during the year (at an introductory level in the first semester and in more depth during the second semester) helped me learn the material better by the end of the course.”

2-semester students

Strongly Disagree 0 0%

Disagree 1 3%

Neither agree nor disagree

1 3%

Agree 12 40%

Strongly Agree 16 53%

Summary• 2-cycle sequence allows a much better

experience for 1-semester students• 2-semester students show increased learning

and prefer the 2-cycle approach• The most significant problems (lack of specific

text and transfer students) are minor

For copy of PowerPoint or more info: dougms@goshen.edu

Questions??