A New and Diastereoselective Synthesis of<i>Threo</i>-Aryl-2-Piperidylmethanol Derivatives

Delgado, Antonio; Hospital, Susana; Mauleón, David; Pérez, Francese

doi:10.1080/00397918808068270

Cited by 6 publications

(1 citation statement)

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“…As a consequence the oxazolidinone 17b was readily saponified upon treatment with base. 18 The otherwise much more tedious ring opening (vide infra) proceeded smoothly within one hour and generated the amino alcohol 18 which was subsequently N-Z-protected to the azabicyclo[3.2.0]heptane 13 (Scheme 8). The compound so obtained proved to be identical in all respects with the one previously prepared from ester 12a by Grignard addition (cf.…”

Section: Methodsmentioning

confidence: 99%

The Stereoselective Synthesis of 2-Substituted 3-Azabicyclo[3.2.0]heptanes by Intramolecular [2+2]-Photocycloaddition Reactions

Bach¹,

Krüger²,

Harms³

2000

Synthesis

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The stereoselective synthesis of the 3-azabicyclo[3.2.0]heptanes 6, 12, 13, 17, 22, 23 and 24 by an intramolecular [2+2]-photocycloaddition is described. The product yield was good to excellent in almost all cases studied (65-87%) except for a single example (21 → 24) in which a low yield was recorded (22%). The facial diastereoselectivity of the reaction is high if a-branched N,Ndiallylamines are employed as starting materials which either bear a comparably bulky a-substituent (25) or the a-substituent of which is connected to the nitrogen atom via an oxazolidinone ring (16, 19, 20, 21). These diallylamines were readily prepared from methionine and it was shown that their preparation proceeded free of racemization. The photocycloaddition could be conducted in two ways. The more general method is based on the Cu-catalyzed reaction which was carried out with Cu(OTf) 2 in diethyl ether and is applicable to essentially all substrates under scrutiny. The N-cinnamyl substituted substrates 5, 11, 16 and 25 which possess a comparably low lying T 1 state reacted well in a triplet-sensitized process employing acetophenone as the sensitizer and acetone as the solvent.

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Section: Methodsmentioning

confidence: 99%