227804-97-9Relevant academic research and scientific papers
Formaldehyde SAMP-hydrazone as a neutral formyl anion equivalent: Asymmetric synthesis of substituted β-formyl δ-lactones and furofuran lactones
Enders, Dieter,Vazquez, Juan,Raabe, Gerhard
, p. 893 - 901 (2000)
An efficient asymmetric synthesis of α-substituted β-formyl δ- lactones 5 (de ≥98%, ee = 80-95%) and 4-substituted furofuran lactones 6 (de ≥ 98%, ee = 80->98%) in acceptable overall yields is reported. Key steps of the new procedure are an asymmetric Michael addition of formaldehyde SAMP- hydrazone (1) to 5,6-dihydro-2H-pyran-2-one (2) under neutral conditions, followed by trans-selective α-alkylation and subsequent cleavage of the auxiliary by ozonolysis or a hydrolytic domino reaction protocol, respectively. The absolute configurations given for the title compounds are based on three X-ray structure analyses and NOE measurements.
