Chemistry 251 Laboratory -- Spring 2001
Piperine Project Home Page

Index

• 2000 Piperine Synthesis Home Page
• Students working on this project
• Table of Reagents and Amounts Available

Piperine is a component of black pepper which causes sneezing. Its presence in pepper was discovered many years ago, and its structure was elucidated near the beginning of the century. The synthesis starts with an allylic, radical halogenation to introduce a bromine atom. An Arbuzov reaction with triethyl phosphite displaces the bromine and produces a phosphonate that is then coupled to piperonal using a modified Wittig reaction. Hydrolysis of the ester, formation of the acid chloride using oxalyl chloride, and coupling to piperidine completes the synthesis.

The table below lists the chemicals that we will have available for this project. If you need something that is not on this list, consult with the mentor for your project. Also note the "Amount/group" column. This is the total amount of material available for each group to use on the project.

Reagent	Source	Amount/group	Location	Comments
Methyl crotonate	Aldrich Cat. # 13,945-9	10 mL	TA room
N-Bromosuccinimde	Aldrich Cat. # B8,125-5	10 g	TA room
Benzoyl Peroxide, 97%	Aldrich Cat. # 17,998	1 g	Fridge (50 g bottle)	Caution: Benzoyl peroxide should be handled with care. Use a plastic spatula when transferring.
Triethyl phosphite	Aldrich	1 g	TA Rooom
Piperonal	Aldrich	1 g	TA Rooom
Sodium methoxide	Aldrich	2 g	TA Rooom
Oxalyl chloride	Aldrich Cat. # 0-880-1	2 mL	TA Rooom	Be sure to use pure oxalyl chloride, not the 2M oxalyl chloride in dichloromethane. Work in the hood, and dispense the oxalyl chloride under nitrogen.
Piperidine	Aldrich	2 mL	TA Rooom