Total Syntheses

Reaction scheme for total synthesis of the natural product Hemibrevetoxin B (Part 2) (Holton)
Total synthesis of Hemibrevetoxin B (Part 2) (Holton):
Reference:Zakarian, A.; Batch, A.; Holton, R. A.. J. Am. Chem. Soc. 2003, 125, 7822-7823. DOI (Part 1)
Reactions:O-SiEt3 → O-H • Wittig-alkyl → Ene-cis • Selenide → Selenoxide • O-Bn → O-H • O-SiiPr3 → O-H • RCM → Ring-O • Ether-7 • Bicyclo(550) • Peterson → Ene • Mg-Silane • HWE → EnoateAmide • B-Allyl+Aldehyde • Peterson → Diene • Selenoxide-Ei → Ene • Selenoetherification • Ether-7 • Bicyclo(440)-oxa • Bicyclo(540)-oxa • CarboxAcid → Alkyl-OH • Alkyl-OH → Aldehyde-α-OR • Diol-1,2 cleavage • Hydrogenation EnoateEster • O-H → O-SiMe3 • CarboxAmide → Aldehyde • Alkyl-OH → Aldehyde • Ketal → Diol-1,3 • O-MOM → O-H • O-SnR3 → O-SO2Ar • CompNu-O-H/O-H+RSO2X • Diol-1,3 → Stannadioxolane •
Reagents:AlH4-Li+ • DMSO, (COCl)2 (Swern) • PPh3=CH-Me • HF·Py • H2O2 • Li°/NH3 • MgCH2-SiMe3 • KOtBu • Fluoride, R4N+ • Periodate, sodium • Weinreb phosphonate • NaH • H2, Pd • SiMe3-Cl • AlHiBu2 • Allyl-SiR3 • Allyl-BR2 • Chiral auxiliary (boronate) • KOtBu • Sulfonic acid, Camphor • SnBu2(O) • DMSO, (COCl)2 (Swern) • LiBF4 • Grubbs II • TsCl • Imidazole • Iodide, R4N+ •