CH 220 1st Edition Lecture 5Outline of Current Lecture I. Types of alkyl groupsII. CycloalkanesIII. Cyclohexane – chair conformationIV.Naming cycloalkanesCurrent Lecture I. Types of alkyl groupsa. Classified by the connection sitei. A carbon at the end of a chain is known as a primary alkyl group 1ii. A carbon in the middle of a chain is known as a secondary alkyl group 2iii. A carbon with three carbons attached to it is a tertiary alkyl group 3iv. A carbon with four carbons attached to it is a quaternary alkyl group 4b. These classifications are not used to name, just to describe the neighbors of the carbonc. When referring to the classification of hydrogen, it takes on the classification of the carbons that they are attached to, for instance if a carbon is attached to threeother carbons and one hydrogen, then the hydrogen would be attached to the tertiary carbon and therefore be a tertiary hydrogenII. Cycloalkanesa. Cycloalkanes are saturated hydrocarbons in a ring/circle instead of being in a straight chaini. Cyclopropane, cyclobutane, cyclopentane, cyclohexaneii. Cyclohexane looks like benzene, but is composed of single bonds rather than alternating single-double bondsb. Cycloalkanes are not isomers of alkanesi. Formula for cyclopropane is C3H6ii. Formula for propane is C3H8iii. They have very different propertiesIII. Cyclohexane a. Adopts a chair confirmation, with 3 hydrogens pointing straight down and 3 hydrogens pointing straight up (axial hydrogens) and 6 hydrogens spaced around the structure (equatorial hydrogens)b. Can also adopt a boat confirmation, meaning that 2 of the hydrogens are closer together, but this isn’t as stable as chair confirmationThese notes represent a detailed interpretation of the professor’s lecture. GradeBuddy is best used as a supplement to your own notes, not as a substitute.IV. Naming cycloalkanesa. Find the parent # of carbons in the ringb. Number substituents, giving the lowest numbersc. Make sure substituents are listed alphabeticallyd. Make sure to write di- or tri- before the substituents if there are multiple of the same type: for instance, below, is
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