1000004-75-0

Upstream product

• 5674-01-1 2-methylallylmagnesium chloride 
• 100-39-0 benzyl bromide 
• 111998-83-5 triisopropylsilyloxy-acetaldehyde 
• 1000004-74-9 C₁₅H₃₂O₂Si 

Downstream Products

• 1092680-09-5 C₂₁H₃₈O₃Si 

Relevant academic research and scientific papers

Diastereoselective, three-component cascade synthesis of tetrahydrofurans and tetrahydropyrans employing the tandem Mukaiyama aldol-lactonization process

(Chemical Equation Presented) A full account of studies leading to the development of a cascade sequence that generates as many as two C-C bonds, one C-O bond, and three new stereocenters providing substituted tetrahydrofurans (THFs) from simple γ-ketoaldehydes and thiopyridyl ketene acetals is described. The process involves a tandem Mukaiyama aldol-lactonization (TMAL) and accumulated evidence suggests the intermediacy of a silylated β-lactone that is intercepted by the pendant ketone. Formation of a cyclic oxocarbenium is followed by reduction with silicon-based nucleophiles leading to a highly diastereoselective synthesis of tetrahydrofurans. This cascade process has now been extended to the synthesis of tetrahydropyrans from simple δ-ketoaldehydes. The stereochemical outcome of the cascade processes described was determined by NOE correlations, coupling constant analysis, and X-ray crystallography of the derived oxygen heterocycles and is in accord with established and recently proposed models for nucleophilic additions to cyclic 5- and 6-membered oxocarbenium ions. The utility of this process was demonstrated by the synthesis of the tetrahydrofuran fragment of colopsinol B.

Highly diastereoselective, tandem, three-component synthesis of tetrahydrofurans from ketoaldehydes via silylated β-lactone intermediates

(Chemical Equation Presented) Like falling dominoes! A novel tandem, three-component reaction is described that generates up to two C-C bonds, one C-O bond, and three additional stereocenters leading to substituted tetrahydrofuran units. This process involves a tandem Mukaiyama aldol-lactonization/reductive cyclization and proceeds via a silylated β-lactone intermediate. The method was applied to prepare the tetrahydrofuran fragment of colopsinol B. Py = 2-pyridyl.

Diastereoselective synthesis of tetrahydrofurans via mead reductive cyclization of keto-β-lactones derived from the tandem Mukaiyama aldol lactonization (TMAL) process

(Chemical Equation Presented) The development of a diastereoselective, three-step strategy for the construction of substituted tetrahydrofurans from alkenyl aldehydes based on the tandem Mukaiyama aldol-lactonization process and Mead reductive cyclization of keto β-lactones is reported. Stereochemical outcomes of the TMAL process are consistent with models established for Lewis acid-mediated additions to α-benzyloxy and β-silyloxy aldehydes while reductions of the five-membered oxocarbenium ions are consistent with Woerpel's models. Further rationalization for observed high diastereoselectivity in reductions of α-silyloxy 5-membered oxocarbenium ions based on stereoelectronic effects are posited. A diagnostic trend for coupling constants of γ-benzyloxy β-lactones was observed that should enable assignment of the relative configuration of these systems.