Lewis-acid-promoted additions of carbonyl compounds to donor-acceptor substituted cyclopropanes: a new synthesis of 2,3-dihydrofurane derivatives

✍ Scribed by Hans-Ulrich Reissig

• Book ID: 104234137
• Publisher: Elsevier Science
• Year: 1981
• Tongue: French
• Weight: 194 KB
• Volume: 22
• Category: Article
• ISSN: 0040-4039
• DOI: 10.1016/s0040-4039(01)81805-0

✦ Synopsis

Methyl 2,3-dihydrofurane-3-carboxylates are synthesized from siloxycyclopropaneesters and ketonesin the presence of Tic14 with good yields. During the last decade cyclopropanes have attained remarkable importance for the construction of carbon skeletons '. The "oxycyclopropanes" (l_) -(3_) are very useful 2 intermediates in organic synthesis . To our knowledge, there is only one publication describing the use of the strain energy inherent in a compound of type (1) -(3) for the formation of a C-C bond; according to KUWAJIMA and NAKAMURA 3 l-ethoxy-l-trimethylsiloxycyclopropane (4) smoothly adds to aldehydes R-CHO under Tic14 activation affording the r-lactones (5). Therefore (4) can be regarded as homoenolate anion equivalent.