The stereocontrolled total synthesis of altohyrtin A/spongistatin 1: the AB-spiroacetal segment.
The convergent synthesis of the C1-C15 AB-spiroacetal subunit of altohyrtin A/spongistatin 1 is described. This highly stereocontrolled synthesis relies on matched boron aldol reactions of chiral methyl ketones, under Ipc(2)BCl mediation, to establish the C5, C9 and C11 stereocentres, and formation of the desired thermodynamic spiroacetal under acidic conditions. The scalable synthetic sequence developed provided access to multi-gram quantities of , thus enabling the successful completion of the total synthesis of altohyrtin A/spongistatin 1, as reported in Part 4.
University Chemical Laboratory, Lensfield Road, University of Cambridge, Cambridge, UKCB2 1EW. ip100@cam.ac.uk
Ian
I
Paterson
Mark J
MJ
Coster
David Y-K
DY
Chen
Renata M
RM
Oballa
Debra J
DJ
Wallace
Roger D
RD
Norcross
D000080:Acetals / Q000138:chemical synthesis; D000438:Alcohols / Q000737:chemistry; D000970:Antineoplastic Agents / Q000138:chemical synthesis*; D001895:Boron / Q000737:chemistry; D007659:Ketones / Q000737:chemistry; D018942:Macrolides / Q000138:chemical synthesis*; D015394:Molecular Structure; D013141:Spiro Compounds / Q000138:chemical synthesis; D013237:Stereoisomerism; D013816:Thermodynamics; D000095702:Polyether Toxins
D000080:Acetals; D000438:Alcohols; D000970:Antineoplastic Agents; D001895:Boron; D007659:Ketones; D018942:Macrolides; D013141:Spiro Compounds; C083856:spongistatin 1; D000095702:Polyether Toxins