Chiral recognition of carboxylic acids by Tröger’s base derivatives

The readily accessible optically active methoxy Tröger’s base 3 and the corresponding α,α′-diphenyl carbinol derivative 5 are useful for the recognition and enantiomeric discrimination of representative chiral carboxylic acids.

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(5R,11R)-Methoxy Tröger’s baseC17H18N2O2Ee ⩾ 98%[α]D25=-242±5 (c 0.22, CHCl3)Source of chirality: resolutionAbsolute configuration: (5R,11R)

(5R,6S,11R)-2,8-Dimethoxy-6-yl-(diphenylmethanol)-6H,12H-5,11-methanodibenzo[b,f][1,5]diazocineC30H28N2O3Dr = 100%[α]D25=+27±1 (c 0.5, CHCl3)Source of chirality: diastereoselective synthesisAbsolute configuration: (5R,6S,11R)