Organic Chemistry Oxygen and Sulfur in Organic Compounds

Organic Chemistry Oxygen and Sulfur in Organic Compounds 1

Chapter 12 Part 05 Thiols Page 102 2

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 3

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 separated by a hyphen name of the thiol, - if branched chain, always number giving the - SH group priority and name the substituents like you would for any other organic compound 4 (lowest numbers, alphabetical, etc. )

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

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

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

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

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

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

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) 11

3. Thiols methanethiol & ethanethiol - added to odorless natural gas after the New London, Texas gas explosion in 1937 http: //www. youtube. com/watch? v=Zq. CRNt. Z 12 mo&playnext=1&list=PL 0 BAC 9 A 84 ED 0009 A 7 12

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 13