The stereocontrolled total synthesis of altohyrtin A/spongistatin 1: the CD-spiroacetal segment.
Stereocontrolled syntheses of the C16-C28 CD-spiroacetal subunit of altohyrtin A/spongistatin 1 , relying on kinetic and thermodynamic control of the spiroacetal formation, are described. The kinetic control approach resulted in a slight preference (60 : 40) for the desired spiroacetal isomer. The thermodynamic approach allowed ready access to the desired spiroacetal by acid-promoted equilibration, chromatographic separation of the C23 epimers and resubjection of the undesired isomer to the equilibration conditions. This scalable synthetic sequence provided multi-gram quantities of , thus enabling the successful completion of the total synthesis of altohyrtin A/spongistatin 1, as reported in Part 4 of this series.
Paterson
Ian
I
University Chemical Laboratory, Lensfield Road, University of Cambridge, Cambridge, UKCB2 1EW. ip100@cam.ac.uk
Coster
Mark J
MJ
Chen
David Y-K
DY
Gibson
Karl R
KR
Wallace
Debra J
DJ
D000080:Acetals / Q000138:chemical synthesis; D000970:Antineoplastic Agents / Q000138:chemical synthesis*; D007700:Kinetics; D018942:Macrolides / Q000138:chemical synthesis*; D015394:Molecular Structure; D013141:Spiro Compounds / Q000138:chemical synthesis; D013237:Stereoisomerism; D013816:Thermodynamics; D000095702:Polyether Toxins
D000080:Acetals; D000970:Antineoplastic Agents; D018942:Macrolides; D013141:Spiro Compounds; C083856:spongistatin 1; D000095702:Polyether Toxins