Asymmetric synthesis of seven-membered carbocyclic rings via a sequential oxyanionic 5-exo-dig cyclization/claisen rearrangement process. Total synthesis of (-)-frondosin B.
Appropriately substituted nonracemic allyl alcohols, readily prepared from the corresponding enones by application of the CBS methodology, were converted to optically active cycloheptenone derivatives with almost complete transfer of chirality via an efficient "one-pot", cycloisomerization/Claisen rearrangement process. This methodology was directly applied to the expedient total synthesis of (-)-frondosin B.
Ovaska
Timo V
TV
Department of Chemistry, Connecticut College, 270 Mohegan Avenue, New London, Connecticut 06320, USA. tVoVa@conncoll.edu
Sullivan
Jonathan A
JA
Ovaska
Sami I
SI
Winegrad
Jacob B
JB
Fair
Justin D
JD
D000838:Anions / Q000737:chemistry*; D003500:Cyclization; D006576:Heterocyclic Compounds, 4 or More Rings / Q000138:chemical synthesis* / Q000737:chemistry; D015394:Molecular Structure; D021241:Spectrometry, Mass, Electrospray Ionization; D013237:Stereoisomerism
D000838:Anions; D006576:Heterocyclic Compounds, 4 or More Rings; C421322:frondosin B