67498-53-7

Upstream product

• 128071-64-7 (3aS,7aS)-3-[1-Chloro-meth-(E)-ylidene]-7a-methyl-hexahydro-benzofuran-2-one 
• 67-56-1 methanol 
• 74723-73-2 1-bromo-8-oxonon-2-yne 
• 50-00-0 formaldehyd 
• 591-49-1 1-methylcyclohex-1-ene 
• 118893-25-7 diethyl 2-(2-methyl-2-cyclohexen-1-yl)propane-1,3-dioate 
• 128071-58-9 (E)-3-Chloro-2-(2-chloro-2-methyl-cyclohexyl)-acrylic acid 
• 128071-53-4 2-Chloro-3-(2-chloro-2-methyl-cyclohexyl)-cycloprop-2-enone 
• 113426-65-6 1-Chloro-1-methyl-2-(2,3,3-trichloro-cycloprop-1-enyl)-cyclohexane 
• 128071-71-6 (2-Chloro-2-methyl-cyclohexyl)-propynoyl chloride 
• 150546-39-7 3-Methyl-3-(1,2-propadienyloxy)-1-cyclohexene 
• 13373-66-5 1-Methyl-2-oxabicyclo<3.3.0^1,5>nonan-3-one 

Relevant academic research and scientific papers

Lactones, part 28: A new approach for the synthesis of α-methylene lactones from alkenes

A facile two-step procedure for synthesis of α-methylene lactones from alkenes and cycloalkenes is presented. Reactions carried out on some monoterpene alkenes afforded corresponding lactones in enantiomerically pure forms. Georg Thieme Verlag Stuttgart.

Strain-Driven Dyotropic Rearrangement: A Unified Ring-Expansion Approach to α-Methylene-γ-butyrolactones

An unprecedented strain-driven dyotropic rearrangement of α-methylene-β-lactones has been realized, which enables the efficient access of a wide range of α-methylene-γ-butyrolactones displaying remarkable structural diversity. Several appealing features of the reaction, including excellent efficiency, high stereospecificity, predictable chemoselectivity and broad substrate scope, render it a powerful tool for the synthesis of MBL-containing molecules of either natural or synthetic origin. Both experimental and computational evidences suggest that the new variant of dyotropic rearrangements proceed in a dualistic pattern: while an asynchronous concerted mechanism most likely accounts for the reactions featuring hydrogen migration, a stepwise process involving a phenonium ion intermediate is favored in the cases of aryl migration. The great synthetic potential of the title reaction is exemplified by its application to the efficient construction of several natural products and relevant scaffolds.

Synthetic studies towards (+)-Dihydroampullicin. Michael addition of N-Boc-2-(tert-butyldimethylsiloxy)-3-methyl-pyrrole to α-methylene lactones

The Michael addition of N-(tert-butoxycarbonyl)-2-(tert-butyldimethylsiloxy)-3-methyl-pyrrole (4) to several α-methylene lactones catalyzed by fluoride ions yielded the corresponding homologated products (26-30) with good yields. Application of this react

Tungsten-Mediated Syntheses of Fused α-Methylenebutyrolactones from Propargyl Bromides Containing Tethered Aldehydes and Ketones

The reaction of CpW(CO)3Na with a number of propargyl bromides with tethered aldehydes and ketones afforded η1-propargyl species that were subsequently transformed into tungsten-η3-2-(methoxycarbonyl)allyl compounds upon treatment with p-TSA/CH3OH; the overall yields exceeded 60%. Sequential treatment of these tungsten-η3-allyl complexes with NOBF4 and NaI in CH3CN led to intramolecular allyltungsten-carbonyl cyclization, yielding fused α-methylene butyrolactones of five-, six-, and seven-membered carbocyclic rings. All the reactions proceeded with high diastereoselectivities except for 9-methylene-7-oxabicyclo[4.3.0]nonan-8-one (22) and 10-methylene-8-oxabicyclo[5.3.0]decan-9-one (23). Modification of the metal center with a chloride ligand led to significant improvement of the trans-stereoselection of 22; the chloride modification did not significantly enhance stereoselection of 23. The stereochemical course of the reaction products is rationalized on the basis of a bicyclic transition-state mechanism.

Synthesis of bicyclic α-methylene butyrolactones via alkoxycarbonylation of molybdenum-propargyl compounds

Syntheses of various bicyclic α-methylene butyroladones from functionalized propargyl bromides were carried out in short steps, the overall yields are reasonable. The key step involves alkoxycarbonylation of molybdenum-propargyl compounds.

Regio- and stereoselective ring-opening reactions of cyclopropenones: α-methylene-γ-butyrolactones via additions of trichlorocyclopropenylium ions to alkenes

The 2-chloro-3-(2'-chloroalkyl)cyclopropenones 4, readily obtained by hydrolysis of the adducts of the trichlorocyclopropenylium ion onto alkenes, thermally rearrange to propiolic acid chlorides 6. Treatment of 4 with TosOH·H2O in CH2/sub