Enantioselective Catalytic Addition of Functionalized Dialkylzinc Compounds to β-Stannylated Aldehydes: A Convenient Preparation of Chiral β- and γ-Functionalized Secondary Alcohols

✍ Scribed by Dr. Walter Brieden; Roswitha Ostwald; Prof. Dr. Paul Knochel

• Publisher: John Wiley and Sons
• Year: 1993
• Tongue: English
• Weight: 407 KB
• Volume: 32
• Category: Article
• ISSN: 0044-8249
• DOI: 10.1002/anie.199305821

✦ Synopsis

To nBuLi (2.9 g. 46 mmol), constantly stirred at -8O"C, precooled pentane was added dropwise until a homogeneous solution was obtained (ca. 20 mL). After one week at -90 "C colorless blocks crystallized with a melting point of -34(2) 'C. rBuLi: tBuLi (2.2 g, 34 mmol) was treated as described for nBuLi (ca. 18 mL pentane added). Crystallization over one week yielded colorless elongated blocks. (rBuLi. Et,O),: From various pentane/Et,O ratios the best results were obtained by first adding 5 mL pentane and then 12 mL E t 2 0 (each precooled to -60 "C) dropwise to solid tBuLi (2.2 g, 34 mmol) at -80 'C. At -90 'C colorless blocks with a melting point of -38(2) "C were formed from the pale yellow solution.