34638-26-1

Upstream product

• 26054-46-6 cis-(±)-2-oxabicyclo[3.3.0]oct-6-en-3-one 
• 34638-25-0 (1R,5S)-2-oxabicyclo[3.3.0]oct-6-en-3-one 

Downstream Products

• 118535-94-7 C₃₁H₂₅Cl₃O₆ 
• 118535-95-8 C₂₄H₂₂Cl₂O₅ 
• 118215-76-2 (4aS,5R,6aS,6bR)-3,5-Bis-benzyloxy-4,4a,5,6,6a,6b-hexahydro-3H-cyclopenta[cd]pentalen-1-one 
• 118215-77-3 C₂₄H₂₆O₃ 
• 118215-72-8 C₂₃H₂₄O₂ 

Relevant academic research and scientific papers

Enantioselective synthesis of cyclopentyltetrahydrofuran (Cp-THF), an important high-affinity P2-ligand for HIV-1 protease inhibitors

A convenient optically active synthesis of (3aS,5R,6aR)-5-hydroxy-hexahydrocyclopenta[b]furan, a high-affinity nonpeptidyl ligand for HIV-1 protease inhibitor 2, is described. The synthesis utilizes commercially available (1R,5S)-(+)-2-oxabicyclo[3.3.0]oct-6-en-3-one as the starting material and oxymercuration or bromohydrin reaction as the key step. Enantiopure ligand was converted to protease inhibitor 2.

Studies on the stereoselectivity of osmylation of cis-bicyclooct-6-enes

Treatment of cis-2-oxabicyclooct-6-en-3-one 1 with osmium tetraoxide under a variety of conditions led predominantly to attack from the more hindered face of the alkene to give, after protection of the diol, the endo-acetonide 8 as the major product.It is apparent that the stereochemical outcome of this reaction is due to a directing effect from the lactone carbonyl at C-3 since osmylation of the analogous lactols 3, acetals 4 and cyclic ethers 5 gave attack mainly from the less hindered exo-face.The exo-acetonide 7 was prepared in a 3-stage procedure from cis-bicycloheptenone 6 in 54percent yield.In this case the stereoselectivity of the osmylation reaction was governed, as espected, by the conformation of the bicyclic skeleton, no directing effect from the ketone carbonyl was apparent.

SYNTHESIS AND CHIROPTICAL PROPERTIES OF C3-PERHYDROTRIQUINACENE DERIVATIVES

An efficient, enantioselective synthesis of C3-triketone 1, starting from optically pure lactone 2, which is commercially available in both enantiomeric forms, is described.The absolute configuration of a chiral perhydrotriquinacene derivative is therefore established for the first time by chemical correlation.The stereochemical assignments are also confirmed by the circular dichroism of both (+)-1, which shows a positive Cotton effect, and the tribenzoate (+)-12, which presents a positive exciton chirality.

A Three-step Procedure for the Conversion of γ-Lactones into δ-Lactones

γ-Lactones with a wide range of functional groups are transformed by a three-step procedure into the corresponding δ-lactones in an overall yield of up to 55percent.The novel methodology involves the reduction of a γ-lactone to a γ-lactol followed by a Horner olefination with an excess of lithiated diethyl α-cyano-α-dimethylaminomethylphosphonate to yield a mixture of E/Z-isomeric α-cyano enamines.Acidic hydrolysis of these intermediates affords the desired δ-lactones.By the same reaction sequence δ-lactones can be transformed into the corresponding ε-hydroxy carboxylic acids.