Efficient and convergent stereocontrolled spiroannulation of ketones

✍ Scribed by István E. Markó; Jean-Christophe Vanherck; Ali Ates; Bernard Tinant; Jean-Paul Declercq

• Book ID: 104253391
• Publisher: Elsevier Science
• Year: 2003
• Tongue: French
• Weight: 182 KB
• Volume: 44
• Category: Article
• ISSN: 0040-4039
• DOI: 10.1016/s0040-4039(03)00573-2

✦ Synopsis

Upon treatment with tBuOK/H 2 O, a variety of v-halo-b-keto-ketals undergo smooth cyclisation, affording in excellent yields mono-protected [n,m] spiro bicyclic diketones. This transformation is highly stereoselective producing, in all cases, the diastereoisomerically pure spiro derivatives.