Enantio- und diastereoselektive Synthese von 2-substituierten 1-Bicyclo[3.1.0]hexanolen

Abstract

Nützliche Zwischenstufen für die organische Synthese sind die optisch aktiven, substituierten bicyclischen Cyclopropanole, die mit gängigen Methoden nur schwer zugänglich sind. Sie können nun aus Oppolzer‐N‐Acylcamphersultamen und [Ti(OiPr)2(η2‐Propen)] mit hoher Enantio‐ und Diastereoselektivität einfach hergestellt werden [Gl. (a)]. R=Alkyl, Alkenyl, Benzyl, Alkoxyalkyl, Alkylsiloxyalkyl.

1,n-Dicarbanionic Titanium Intermediates from Monocarbanionic Organometallics and Their Application in Organic Synthesis

“…Sato et al developed an interesting enantioselective synthesis of bicyclic cyclopropanols from N - acylcamphorsultame derivatives. Enantiomeric excesses in the products were up to >98% (Scheme and Table ) 35 …”

“…Sato et al developed an interesting enantioselective synthesis of bicyclic cyclopropanols from N- 11). 230 In view of their versatile new synthesis of dialkylcyclopropylamines from N,N-dialkylcarboxamides by way of titanacyclopropane intermediates generated from Grignard reagents and XTi(Oi-Pr) 3 (X ) Oi-Pr, Me), 207,211 de Meijere et al had also soon turned their attention to the additional synthetic potential of titanacyclopropane intermediates generated by ligand exchange. Their first target in mind was the 3-azabicyclo[3.1.0]hexylamine 67, an essential building block for the commercial antibiotic trovafloxacin.…”