A simple and inexpensive method for the C2 homologation of aldehydes and ketone to 2-alkenals consists of the reaction with allylmagnesium bromide, O-acylation of the resultant 1-alken-4-ol, and ozonolysis.
Enzymatic Lactonization Stategy for Enantioselective Synthesis of a Tetrahydrolipstatin Synthon
作者:A. Sharma、S. Chattopadhyay
DOI:10.1021/jo990370+
日期:1999.10.1
This involved a porcine pancreatic lipase (PPL)-catalyzed delta-lactonization of a racemic 3,5-dihydroxy-2-alkyl ester to produce the lactone with high enantioselectivity (92.8%). The product lactone and its analogues are useful synthons for the asymmetric synthesis of various bioactive compounds, which include the potential anti-obesity compound, tetrahydrolipstatin.
AN EFFICIENT METHOD FOR THE PREPARATION OF HOMOALLYLIC ALCOHOL DERIVATIVES BY THE REACTION OF ALLYL IODIDE WITH CARBONYL COMPOUNDS IN THE PRESENCE OF STANNOUS HALIDE
Allyl iodide reacts in situ under mild conditions with stannous halide to form allyltin dihaloiodide, which in turn reacts with carbonyl compounds in an aprotic solvent to give the corresponding ho...
Synthesis of conjugated γ- and δ-lactones from aldehydes and ketones via a vinylation(allylation)-ring closing metathesis–oxidation sequence
作者:J.Alberto Marco、Miguel Carda、Santiago Rodrı́guez、Encarnación Castillo、Marı́a N. Kneeteman
DOI:10.1016/s0040-4020(03)00584-2
日期:2003.6
aldehydes and ketones followed by O-allylation of the obtained carbinols gave the corresponding allyl or homoallyl ethers, respectively. Ring-closing metathesis of these compounds afforded in many cases cyclic ethers (dihydrofurans and dihydropyrans, respectively) bearing disubstituted and trisubstituted CC bonds. These were then subjected to allylic oxidation to yield conjugated γ- and δ-lactones. Reasons