Highly selective chirally templated isomünchnone cycloadditions of achiral aldehydes: Synthesis of an enantiopure α,β-dihydroxyacid
摘要:
Additions of p-nitro- and p-methoxybenzaldehyde to isomunchnone derivatives of (5S)-phenyloxazin-3-one and -2,3-dione led to corresponding adducts (3,4,6) with excellent diastereofacial and exo-selectivity, Hydrolysis and subsequent cleavage of adduct 3 permitted recovery of the original template and furnished dihydroxyacid 9 that was transformed into the known ethyl ester 10. Comparison of its optical rotation with the literature value confirmed its high optical purity. (C) 1997 Elsevier Science Ltd.
Novel Chiral Templates for 1,3-Oxazolium-4-olate (Isomünchnone) Cycloadditions: (5 R)- and (5 S)-Phenyloxazin-2,3-dione
摘要:
Cycloadducts (4-10) were synthesised From isomunchnone derivatives of (5R)- and (SS)-phenyloxazin-2,3-dione by rhodium(II)-catalysed decomposition. High endo/exo-selectivities for additions to carbon-carbon dipolarophiles were observed. (C) 1997 Elsevier Science Ltd.
Novel Chiral Templates for 1,3-Oxazolium-4-olate (Isomünchnone) Cycloadditions: (5 R)- and (5 S)-Phenyloxazin-2,3-dione
作者:Richard Angell、Michael G.B. Drew、Marion Fengler-Veith、Harry Finch、Laurence M. Harwood*、Archie W. Jahans、Toby T. Tucker
DOI:10.1016/s0040-4039(97)00557-1
日期:1997.4
Cycloadducts (4-10) were synthesised From isomunchnone derivatives of (5R)- and (SS)-phenyloxazin-2,3-dione by rhodium(II)-catalysed decomposition. High endo/exo-selectivities for additions to carbon-carbon dipolarophiles were observed. (C) 1997 Elsevier Science Ltd.
Highly selective chirally templated isomünchnone cycloadditions of achiral aldehydes: Synthesis of an enantiopure α,β-dihydroxyacid
作者:Michael G.B Drew、Marion Fengler-Veith、Laurence M Harwood、Archie W Jahans
DOI:10.1016/s0040-4039(97)00919-2
日期:1997.6
Additions of p-nitro- and p-methoxybenzaldehyde to isomunchnone derivatives of (5S)-phenyloxazin-3-one and -2,3-dione led to corresponding adducts (3,4,6) with excellent diastereofacial and exo-selectivity, Hydrolysis and subsequent cleavage of adduct 3 permitted recovery of the original template and furnished dihydroxyacid 9 that was transformed into the known ethyl ester 10. Comparison of its optical rotation with the literature value confirmed its high optical purity. (C) 1997 Elsevier Science Ltd.