1 Organic Chemistry Oxygen and Sulfur in Organic Compounds

2 Chapter 12 Part 05 Thiols Page 102

3 1.Thiols -contain the sulfhydryl or mercapto functional group, -SH -general formula RSH -derivatives of hydrogen sulfide gas where one H is replaced by an R group H S H R S H

4 2.Nomenclature of Thiols - determine main chain (longest continuous chain of C atoms that contains the –SH). Keep the entire name; don’t remove any letters -add the suffix –thiol - If two thiol groups – dithiol - If three thiol groups – trithiol - number the chain to give the C bearing the –SH the lowest possible number - place this number in front of the name of the thiol, separated by a hyphen - if branched chain, always number giving the - SH group priority and name the substituents like you would for any other organic compound (lowest numbers, alphabetical, etc.)

5 H C SH C H HH C H C H H HH 1-butanethiol 2.Nomenclature Name the following thiol.

6 H C H C H HH C H C H H HSH 2-butanethiol 2.Nomenclature Name the following thiol.

7 2.Nomenclature Name the following thiol. 1,1-pentanedithiol SH C H C H HH C H C H H H H H C

8 4-bromo-3-hexanethiol 2.Nomenclature Name the following thiol. H C H C H BrSH C H C H H H H H H C H C H

9 2.Nomenclature Name the following thiol. trans-3-amino-1-cyclopentanethiol SH H2NH2N

10 3.Nomenclature Name the following thiol. cis-1,2-cyclohexanedithiol SH

11 3.Thiols -hydrogen sulfide gas smells like rotten eggs -thiols have offensive odors -Examples 1-propanethiol (found in onions & garlic – makes eyes tear (lachrimator)) 3-methyl-1-butanethiol & trans-2-butene-1-thiol (found in skunk urine) 2-chloroethylsulfide (mustard gas)

12 3.Thiols methanethiol & ethanethiol -added to odorless natural gas after the New London, Texas gas explosion in

13 3.Thiols -important in biochemistry -two –SH groups can be oxidized (hydrogens removed between them) to form disulfide linkages (hold protein chains together) - helps to determine the shapes of protein molecules