Subject(s)
Ethers/chemistry , Metals/chemistry , Silanes/chemical synthesis , Alcohols/chemistry , Alkenes/chemistry , Carbon/chemistry , Catalysis , Crystallography, X-Ray , Ether/chemistry , Hydrogen/chemistry , Hydrogen Bonding , Lactones/chemistry , Models, Chemical , Oxygen/chemistry , Silanes/chemistry , StereoisomerismABSTRACT
[reaction: see text] A stereoselective synthesis of the GHIJ fragment of brevetoxin A utilizing a convergent assembly strategy is described. Glycolate alkylation, ring-closing metathesis, and Hosomi-Sakurai reactions were central operations in the construction of the G ring and J ring subunits, which were united through a Horner-Wadsworth-Emmons coupling. Subsequent dehydrative cyclization produced an endocyclic enol ether that was further elaborated to the tetracyclic GHIJ fragment of brevetoxin A.
Subject(s)
Marine Toxins/chemical synthesis , Oxocins/chemical synthesis , Marine Toxins/chemistry , Molecular Structure , Oxocins/chemistry , StereoisomerismABSTRACT
[reaction: see text] In examining the scope of the di-tert-butylsilylene transfer to gem-disubstituted alkenes to form silacyclopropanes, we discovered an unprecedented reaction of homoallylic ethers. When silylene transfer was performed at room temperature or above, two di-tert-butylsilylene units were incorporated into the molecule, and complete rearrangement of the carbon backbone occurred. This report describes the scope of this unique reaction as well as the mechanistic studies conducted that led to a proposed mechanism.
