Baker's yeast reduction of arylalkyl and arylalkenil γ- and δ-keto acids

Palladium-Catalyzed Intramolecular Asymmetric Hydroamination, Hydroalkoxylation, and Hydrocarbonation of Alkynes

“…In a similar way, the absolute configuration of the hydroalkoxylation product 8a (80% ee) was determined by transforming it to the known compound 12 (eq 9). It is known in the literature that (+)-2-phenethyltetrahydrofuran [α] 23 D = +4.2 ( c 1.06, CHCl 3 ) has S -configuration . Since the optical rotation of 12 was [α] 25 D = +2.8 ( c 1.0, CHCl 3 ), it was unequivocally confirmed that the absolute configuration of 8a is S .…”

Enantioselective γ-borylation of unsaturated amides and stereoretentive Suzuki–Miyaura cross-coupling

“…NaOH affords the known chiral 5-substituted-γ-lactone 23 (95%). 35 As an alternative to palladium-catalyzed cross-coupling, the morpholine amide derivative 6c undergoes stereoretentive cross-coupling with 2-lithiothiofuran under the conditions developed by Aggarwal 2 e to give 24c (84%). Compound 6c also undergoes BCl 3 -assisted amination with benzyl azide under the conditions reported by Knochel 36 to form the γ-amino acid derivative 25c (65%).…”

Synthesis of cyclic ethers by cyclodehydration of 1, n -diols using heteropoly acids as catalysts

“…Many of the commonly used synthetic approaches for the formation of cyclic ethers, including cycloaddition and cyclization, involve chlorine chemistry or heavy metals at different levels [ 6 , 7 ]. Additionally, cyclization reactions are often conducted under acidic conditions [ 8 , 9 ]. Cyclodehydration of 1, n -diols to cyclic ethers is an industrially important reaction [ 4 ].…”