Abstract
Novel 1-aryl-9H-fluoren-9-ols 1 were conveniently synthesized by using the ester-mediated nucleophilic aromatic substitution on 2,6- dimethoxybenzoate 2 by aryl Grignard reagents as the key step. Racemic 1- phenylfluorenol 1a was converted to the diastereomeric esters 8 of (S)-2'- methoxy-1,1'-binaphthyl-2-carboxylic acid, which were readily separable by silica-gel column chromatography. Reduction of the optically pure diastereomer (+)-8 with LiAlH4 accompanied an appreciable racemization to give (+)-1a of 89% ee, which provides the first isolation of an optically active fluorenol of defined enantiomeric purity. Intrinsic chiral induction abilities of the 9-fluorenols 1 were examined in the atrolactic acid synthesis from phenylglyoxylates 9 and methylmagnesium iodide with diastereoselectivity of up to 85% de and the binaphthyl coupling of 1- methoxy-2-naphthoates 11 with 2-methoxy-1-naphthylmagnesium bromide with up to 73% de.
Original language | English |
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Pages (from-to) | 619-626 |
Number of pages | 8 |
Journal | Chirality |
Volume | 10 |
Issue number | 7 |
DOIs | |
Publication status | Published - 1998 Jan 1 |
Keywords
- Asymmetric synthesis
- Atrolactic acid derivatives
- Biaryl coupling reaction
- Diastereoselective reaction
- Grignard reaction
- Nucleophilic aromatic substitution
- Optical resolution
ASJC Scopus subject areas
- Analytical Chemistry
- Catalysis
- Pharmacology
- Drug Discovery
- Spectroscopy
- Organic Chemistry