Studies in cuprate rearrangement and stannylcupration: Application to the stereo- and enantiospecific synthesis of a stannyldiene C10–C15 fragment of des-epoxy-rosaramycin

Enantioselective, Catalytic One‐Pot Synthesis of γ‐Butyrolactone‐Based Fragrances

“…: 0 : 2:0 : 98) was obtained as colourless oil and has a walnut odour. The analytical data are in accordance with literature , . R f ( n‐ pentane/acetone 80 : 20)=0.55.…”

“…GC: t R [min]=28.8 [(3 R , 4 S ), 99 % ee , dr : 0 : 2:0 : 98], 27.5 (3 S ,4 R ), 31.3 (3 S ,4 S ), 31.9 (3 R ,4 R ) (FS Lipodex G, 60 °C–5 min, 1 °C/min to 100 °C, 10 °C/min to 150 °C–1 min). Optical rotation: [ α ] 25 D =−148 (3 R ,4 S ) (c=1, CHCl 3 , >99 % ee , >99 % de ) [literature: [ α ] D =+66.7 (3 S ,4 R ) (neat)] …”

Synthesis of Two Bioactive Natural Products: FR252921 and Pseudotrienic Acid B

“…Purification of the residue by flash chromatography on silica gel (pentane/Et 2 O 100:0 → 50:50) furnished the vinyl iodide 51 (899 mg, 94 %) as a yellow oil. The physical and spectral properties of compound 51 were in accordance with those described in the literature 45 . R f ≈0.25 (PE/EtOAc 85:15); 1 H NMR (400 MHz, CDCl 3 ): δ =6.19 (tq, 1 H, J =7.5, 1.5 Hz), 3.65 (t, 2 H, J =6.4 Hz), 2.41 (br q, 3 H, J =1.3 Hz), 2.31 (q app , 2 H, J =6.6 Hz), 1.90 (br s, 1 H, OH); 13 C NMR (100 MHz, CDCl 3 ): δ =137.1 (d), 96.2 (s), 61.4 (t), 34.0 (t), 27.8 (q); HRMS (CI + , CH 4 ): m / z : calcd for C 5 H 9 OI: 211.9698; found: 211.9695 [ M +H] + .…”

Synthese von Apoptolidinon

“…Das Diol 9 wurde als Diacetat geschützt und unter Standardbedingungen in den Aldehyd 10 überführt. Die Umsetzung von 10 mit dem aus 11 9 zugänglichen Grignard‐Reagens lieferte die vollständige Südhälfte 12 18 ( ds =93:7, bestimmt durch HPLC; Chelatkontrolle10). Hervorzuheben ist die Bildung der Organomagnesiumverbindung in Gegenwart der Alkenylzinngruppierung.…”