Session Start: Sun Jun 17 10:16:23 2007 Session Ident: #Chemistry [10:16] * Now talking in #Chemistry [10:16] * irc.PilotAge.com sets mode: +nt [17:59] * DrSturm has joined #Chemistry [18:01] * ch has joined #Chemistry [18:01] * dp has joined #Chemistry [18:02] hi [18:02] is this working? [18:02] Hi [18:02] oo okay:) [18:04] Can you help with assigning R/S to more than one chiral center molecule? I was getting mixed up on splitting? [18:04] You do not need to assign R/S to any molecules with more than one chiral center [18:05] thank you [18:05] * ch1 has joined #Chemistry [18:06] * ch has quit IRC (Ping timeout: 181 seconds) [18:06] dr. sturm i have wireless internet b/c i live in the school housing, and i keep getting disconnected [18:06] can i email you my questions? [18:07] Sure. [18:07] * mp has joined #Chemistry [18:08] * ch1 has quit IRC (Leaving) [18:09] * carbon has joined #Chemistry [18:10] Can you give an example of a reaction of alcohol and acid? [18:10] An alcohol and an acid react to give an alkene which will be on exam 3 [18:10] I was wondering if when we halogenated an alkane, i.e. etyl alcohol and make it into a nitrile do we have to add NACN or can we just add CN- ? [18:11] NaCN or CN-, either is fine [18:12] hi dr. sturn. for ester formation do we need to know the mech. for the test? [18:13] We didn't talk about the mechanism for ester formation just the reactions [18:13] would we need to know the reactivity of alkyl halides towards alcoholic silver nitrate? [18:14] That is a reaction we will do in the lab, we did not cover this in lecture. [18:15] In writing the oxidation for a primary alcohol can we just write PCC instead of the other chemical formula? [18:16] Yes, that will give an aldehyde. [18:21] * mp has quit IRC (Leaving) [18:24] In doing the reactions, p.245 #7 I was wondering how to write the answer to problem g. [18:25] Skip g [18:25] ok thanks [18:26] For the reactions of alkyl halides and reduction, is the preparation a Grignard reagent? [18:27] Reduction of a Grignard reagent gives an alkane.? [18:29] Would we have to know acid catalysis on page 230 a,b, c [18:29] Did this answer the question dp? [18:29] Yes, I was reading it wrong. [18:30] Yes, on page 230 [18:32] thanks [18:37] Do we need to know the purpose of an absolute ether? [18:38] No. [18:39] Would we have to know how to make hydroxyl groups good leaving groups? [18:40] Just that anytime you have an OH group in an acidic environment it will form a hydronium ion, a good leaving group [18:44] Would it be necessary to know configurational isomers vs. conformational isomers? [18:45] No. [18:49] * guest has joined #Chemistry [18:50] could you talk a little about configuration and confirmation (if we need to know it) [18:50] Don't need to now that [18:50] "know" [18:51] ok thanks [18:51] How would we name the answer in problem 4b. on page 211 [18:51] also, i noticed that meso compounds seem to always be symmetrical...is this a good indicator of a meso compound [18:51] Yes. [18:51] thanks [18:56] in the book it says that the correct oxidizing agent must be chosen in order carboxylic acid...how do you choose the best oxidizing agent for each reaction? [18:58] Assume all primary alcohols will give you a carboxylic acid with any of the oxidizing reagents listed on your green study guide [18:58] Except PCC or K2Cr2O7 special conditions which will give you an aldehyde [18:59] with a primary alcohol [18:59] ok, so it would depend on the product that you wanted to form [18:59] and whether you had a primary alcohol or not [18:59] Secondary alcohols will give you a ketone [18:59] Tertiary alcohols do not oxidize so NR [19:05] for the nucleophilic substitutions on pp. 173 and 174, do we need to know the product names and the reactions? [19:08] Not the names, but you should be able to predict products. [19:12] for the optical activity nomenclature, when is it necessary to do the + and -? [19:15] You can not determine +/- you have to measure it in a lab [19:15] ok, so you wouldnt know it and thus not need it in the nomenclature we are doing? [19:16] Correct. [19:16] ok thanks [19:18] for chapter 5 #4, do we need to understand or be able to right the abbreviations that the answers are provided in? [19:18] *write [19:20] No. [19:20] ok [19:23] one last thing [19:23] could you go over ch. 5 # 6c? [19:25] They are all primary so are ordered based on size, steric factors, n-propyl easiest up to t-butyl which is very sterically hindered to SN2 attack [19:25] but i thought that the degree was only based on the carbon which the Br was attached to [19:26] Yes, hence they are all primary so beyond that you look at size as the SN2 transition state is very crowded, one step mechanism [19:26] ok [19:27] that makes sense [19:27] O.K., any last questions? [19:27] One last ....Can you give an example, if one is in the book or worksheet for alcohols as electrophiles or nucleophiles? [19:29] As a nucleophile in dehydration which is one of the methods to synthesize alkenes and as electrophile in SN1 and SN2 reactions. [19:30] Anything else? [19:30] no, thank you [19:30] no thanks much [19:30] See you all tomorrow. [19:30] do we need to know about the rates and doubling, etc. for sn1 and 2? [19:30] * DrSturm has quit IRC [19:30] * Disconnected Session Close: Sun Jun 17 19:30:51 2007