@article{SchmidtKunz2012, author = {Schmidt, Bernd and Kunz, Oliver}, title = {alpha,beta-Unsaturated delta-Valerolactones through RCM-Isomerization Sequence}, series = {Synlett : accounts and rapid communications in synthetic organic chemistry}, journal = {Synlett : accounts and rapid communications in synthetic organic chemistry}, number = {6}, publisher = {Thieme}, address = {Stuttgart}, issn = {0936-5214}, doi = {10.1055/s-0031-1290488}, pages = {851 -- 854}, year = {2012}, abstract = {alpha,beta-Unsaturated d-lactones are accessible via a sequential ring-closing metathesis (RCM) double-bond migration reaction starting from butenoates of allyl alcohols. This approach proceeds efficiently with lower catalyst loadings and higher initial substrate concentrations compared to the alternative RCM of acrylates derived from homoallylic alcohols.}, language = {en} } @article{SchmidtKunzPetersen2012, author = {Schmidt, Bernd and Kunz, Oliver and Petersen, Monib H.}, title = {Total syntheses of naturally occurring seimatopolide a and its enantiomer from chiral pool starting materials using a bidirectional strategy}, series = {The journal of organic chemistry}, volume = {77}, journal = {The journal of organic chemistry}, number = {23}, publisher = {American Chemical Society}, address = {Washington}, issn = {0022-3263}, doi = {10.1021/jo302359h}, pages = {10897 -- 10906}, year = {2012}, abstract = {Enantioselective total syntheses of both enantiomers of the recently isolated decanolide natural product seimatopolide A are described. The C-2-symmetric building blocks (R,R)-hexa-1,5-diene-3,4-diol (derived from D-mannitol) and its enantiomer (derived from L-(+)-tartrate) serve as key starting materials, which are elaborated in a bidirectional way using a selective mono-cross-metathesis, regio- and stereoselective epoxidation, and regioselective reductive epoxide opening to furnish the first fragment. Both enantiomers of the second fragment, 3-hydroxypent-4-enoic acid, were conveniently obtained through a lipase-catalyzed kinetic resolution and merged with the first fragment via Shiina esterification. An E-selective ring-closing metathesis was used to access the 10-membered lactone. A comparison of the specific optical rotations of synthetic seimatopolides with those reported for the natural product suggests that the originally assigned (3R,6R,7R,9S)-configuration should be corrected to (3S,6S,7S,9R).}, language = {en} } @article{SchmidtKunz2012, author = {Schmidt, Bernd and Kunz, Oliver}, title = {One-Flask tethered ring closing Metathesis-Electrocyclic ring opening for the highly stereoselective synthesis of conjugated Z/E-Dienes}, series = {European journal of organic chemistry}, journal = {European journal of organic chemistry}, number = {5}, publisher = {Wiley-VCH}, address = {Weinheim}, issn = {1434-193X}, doi = {10.1002/ejoc.201101497}, pages = {1008 -- 1018}, year = {2012}, abstract = {A one-flask reaction sequence comprising ring closing metathesis (RCM) of butenoates derived from allylic alcohols and a base-mediated ring opening gives 2Z,4E-configured dienoic acids in high yields and stereoselectivities. Application of the method to the synthesis of the natural product fusanolide A suggests that the originally published structure was erroneously assigned and should be revised.}, language = {en} }