LEADER 00000nam  2200313   4500 
001    AAI3117968 
005    20051017073436.5 
008    051017s2004                        eng d 
020    049665392X 
035    (UnM)AAI3117968 
040    UnM|cUnM 
100 1  Aloise, Allen Dennis 
245 10 I. Synthesis of cyclooctenones using intramolecular 
       hydroacylation. II. Development of a catalytic 
       enantioselective thiol ester aldol reaction  
300    183 p 
500    Source: Dissertation Abstracts International, Volume: 65-
       01, Section: B, page: 0219 
500    Adviser: Matthew D. Shair 
502    Thesis (Ph.D.)--Harvard University, 2004 
520    The discovery and development of a catalytic reaction to 
       synthesize cyclooctenones via intramolecular 
       hydroacylation is described in this thesis. Rhodium 
       catalysts were found to promote an intramolecular 
       hydrometallation of 5-cyclopropyl-pent-4-enals, followed 
       by cyclopropane ring fragmentation and reductive 
       elimination, to afford cyclooctenones. Cationic Rh(I) 
       catalysts, of the type [Rh(dppe)]X, were found to be 
       superior to neutral Rh(I) catalysts for promoting the 
       reaction and facilitating cyclopropane ring fragmentation.
       Substituted cyclooctenones, including fused 5-8 and 6-8 
       ring systems, were constructed. A deuterium labeling study
       indicated that E- and Z-5-cyclopropyl-pent-4-enals proceed
       through different reaction mechanisms to their 8-membered 
       ring products 
520    Also described in this thesis is the development of a 
       catalytic enantioselective thiol ester aldol reaction. 
       Methyl malonic acid half thiol esters (MAHTs) and a 
       variety of aldehydes were found to participate in a 
       decarboxylative propionate aldol reaction that directly 
       afforded alpha-methyl-beta-hydroxythiol esters with syn 
       diastereoselectivity. The reaction was catalyzed by 20 
       mol% of copper(II) 2-ethylhexanoate in combination with 20
       mol% of 5-methoxybenzimidazole and carried out at room 
       temperature. The use of chiral bis(oxazoline) ligands in 
       combination with copper(II) triflate was found to promote 
       catalytic enantioselective decarboxylative aldol reactions
       in up to 95% yield and 95% enantiomeric excess. A 
       stereochemical model is presented that accounts for the 
       observed aldol product distribution and stereochemistry 
590    School code: 0084 
590    DDC 
650  4 Chemistry, Organic 
690    0490 
710 20 Harvard University 
773 0  |tDissertation Abstracts International|g65-01B 
856 40 |uhttp://pqdd.sinica.edu.tw/twdaoapp/servlet/