158071-58-0

Upstream product

• 66680-87-3 (E)-1-phenyl-(2-tributylstannyl)ethene 
• 16212-07-0 trans-cinnamyl phenyl sulfone 
• 4392-24-9 Cinnamyl bromide 
• 4364-06-1 (E)-cinnamaldehyde dimethylacetal 
• 32323-44-7 5-(dibromomethylene)-2(5H)-furanone 
• 32323-47-0 (5Z)-4-bromo-5-(bromomethylene)-2-(5H)-furanone 
• 676556-27-7 (Z)-4-bromo-5-(trans-3-phenyl-2-propenylidene)-2(5H)-furanone 
• 676556-23-3 5-[(E)-1-Bromo-3-phenyl-prop-2-en-(Z)-ylidene]-5H-furan-2-one 
• 1775-46-8 3,5-dibromolevulinic acid 

Downstream Products

• 1422559-76-9 (5R,7R,8S,9S)-9-bromo-8-hydroxy-7-phenyl-1,6-dioxaspiro[4.4]non-3-en-2-one 
• 918906-87-3 8-epi-crassalactone D 

Relevant academic research and scientific papers

Ring-Closing Metathesis Reactions of Acyloxysulfones: Synthesis of γ-Alkylidene Butenolides

An acyloxysulfone ring-closing metathesis/sulfone elimination sequence has been developed for the preparation of various γ-alkylidene butenolides. The elimination is proposed to proceed via an E1cb mechanism leading to (Z)-γ-alkylidene butenolides as the major products.

A Novel Access to γ-Alkylidenebutenolides: Sequential Stille Couplings of Dibromomethylenebutenolides

γ-(Dibromomethylene)butenolide (2) and β-bromo-γ- (bromomethylene)butenolide (Z-5), both of which obtained from dibromolevulinic acid (6) in a single step, underwent Pd-catalyzed couplings with phenyl- or styryltributylstannane giving mono-bromobutenolides with excellent stereo- and regiocontrol. A second Stille coupling or the reduction with Zn dust led to bromine-free γ-alkylidenebutenolides as single stereoisomers.

Synthesis and stereochemical assignments for goniobutenolides A and B

Goniobutenolides A and B and their C-7 epimers are stereoselectively synthesized using osmium-catalyzed asymmetric dihydroxylation (AD) as the key transformation. The relative and absolute stereochemistry of the natural goniobutenolides A and B are assigned with reference to the spectral data and optical rotations from the literature.