Direct synthesis of δ-lactones from 2-(3-lithiopropyl)-1,3-dioxolane and carbonyl compounds

✍ Scribed by Diego J. Ramón; Miguel Yus

• Publisher: Elsevier Science
• Year: 1990
• Tongue: French
• Weight: 239 KB
• Volume: 31
• Category: Article
• ISSN: 0040-4039
• DOI: 10.1016/s0040-4039(00)97466-5

✦ Synopsis

The reaction of 2-(3-lithiopropyl)-1,3-dioxolane (2). prepared in situ by lithiation of the chloroacetal 1 with lithium naphthalenide at -7X"C, with aldehydes and ketones followed by hydrolysis with hydrochloric acid and final oxidation with PCC or Jones reagent yields the corresponding&lactones 5. Lactonic functionality is fairly common among natural products and in a variety of biologically active molecules, the corresponding Uactones occurring preferentially in products from animal origin.' Thus, many Blactones are significant as insect pheromones' and therefore a lot of synthetic effort has been done to prepare these type of molecules." However, general synthetic routes to6-&tones are relatively scarce' and most methods involve strongly basic conditions.'