Synthese isomerer ϵ‐hydroxycarbonsäure‐methylester

Abstract

Synthesis of Isomeric Methyl ϵ‐Hydroxycarboxylates The synthesis of the three isomeric methyl ϵ‐hydroxycarboxylates 3, 6 and 10a in good overall yields is described.

Silicon- and sulfur-mediated synthesis of benzoannulated cyclooctanols

“…6,11 After protection 12 of the alcohol as TBS-ether, ester 3 13 is reduced 14 to benzyl alcohol 4 15 by DIBAL in high yield (Scheme 3).…”

Axially Chiral Synthons for Dendrimer Synthesis

“…Reduction of carboxyl group of 3 with the diborane-THF complex using known procedure 46,47 yielded alcohols 6 R,S, R, and S in 97, 81, and 87%, respectively. Acetylation of both racemic and chiral alcohols 6 with acetyl chloride proceeded very smoothly giving R,S-, R-, and S-7 in 97, 94, and 99% yields, respectively.…”

Hemirubin: An Intramolecularly Hydrogen-Bonded Analogue for One-Half Bilirubin

“…A solid white material began to separate from the solution; when the NaOH addition was complete, the mixture was stirred for 1 h. After being cooled to 0 °C on an ice bath, the solid was collected by suction filtration and washed with water (3 × 100 mL). Air drying gave 14.0 g (85%) of crude product as white crystalline solid, which is sufficiently pure for use in the next step: mp 80−82 °C (lit . mp 83−84 °C); 1 H NMR ((CD 3 ) 2 SO, 300 MHz) δ 2.56 (t, J = 7.32 Hz, 2H, CH 2 C H 2 COO), 3.13 (t, J = 7.32 Hz, 2H, C H 2 CH 2 COO), 3.53 (s, 3H, OCH 3 ), 7.25−7.35 (m, 2H, 2Ar- H ), 7.40−7.45 (m, 2H, 2Ar- H ), 12.91 (brs, 1H, COO H ) ppm; 13 C NMR ((CD 3 ) 2 SO): δ 29.27 ( C H 2 CH 2 COO), 35.35 (CH 2 C H 2 COO), 51.45 (OCH 3 ), 94.14, 126.6, 130.6, 131.0, 132.0, 141.7, 168.8 (COOH), 172.9 (COOMe) ppm.…”