190782-47-9

Upstream product

• 17401-06-8 (2S,3S)-1,4-bis(benzyloxy)-2,3-butanediol 
• 18162-48-6 tert-butyldimethylsilyl chloride 

Downstream Products

• 174645-33-1 [(1S,2R)-3-Benzyloxy-1-benzyloxymethyl-2-(1-bromo-naphthalen-2-yloxy)-propoxy]-tert-butyl-dimethyl-silane 
• 220482-16-6 (-)-(2R,3S)-1,4-bis(benzyloxy)-2-(2-bromo-3-methoxy-5-methylphenyl)oxy-3-t-butyldimethylsilyloxybutane 
• 203189-64-4 6'-[(1R,2S)-4-benzyloxy-2-(tert-butyldimethylsilyloxy)-1-(benzyloxymethyl)propyloxy]-2,2',6-biphenyltriol 
• 262373-06-8 6'-((1R,2S)-3-Benzyloxy-1-benzyloxymethyl-2-hydroxy-propoxy)-biphenyl-2,6,2'-triol 
• 174645-28-4 C₃₈H₃₂Br₂O₄ 
• 174645-34-2 C₃₈H₃₂O₄ 

Relevant academic research and scientific papers

Atropo-diastereoselective coupling of aryllithiums and arynes — variations around the chiral auxiliary

The atropo-selective coupling of in situ generated arynes and aryllithiums bearing various chiral auxiliaries ortho to lithium (tert-butylsulfoxide, para-tolylsulfoxide, tartrate-derived chiral diethers and oxazolines) is described. Chiral oxazolines showed the best results in terms of yields of coupling products. Different reaction parameters like the nature of the aryne precursor, the oxazoline, the alkyllithium base or the solvent revealed to be crucial for obtaining good yields and for diastereoselection.

Formal synthesis of both atropomers of desertorin C and an example of chirality transfer from a biphenyl axis to a spiro centre and its reverse

In connection with the synthesis of 4,4′,7,7′-tetramethoxy-5,5′-dimethyl-6,8′-bicoumarin (desertorin C) (11) in enantiopure form, the diastereomeric ratios of the products of the reactions between 2-isopropyloxy-6-methoxy-4-methylphenylmagnesium bromide (24) and (4S)-4-isopropyl-2-(2,3,5-trimethoxyphenyl)-4,5-dihydrooxazole (23), between 2,4-dimethoxy-6-methylphenylmagnesium bromide (37) and (4S)-4-isopropyl-2-(2,3-dimethoxy-5-methylphenyl)-4,5-dihydrooxazole (36), and between 2,4-dimethoxy-6-(t-butyldimethylsilyloxy)methylphenyl-magnesium bromide (46) and the oxazole (36) were explored. The major product of the last mentioned reaction was converted into (S,4S)-4-isopropyl-2-(2′-hydroxymethyl-4′,6,6′-trimethoxy-4- methyl-1,1′-biphenyl-6-yl)-4,5-dihydroxazole (49), the axial configuration of which was confirmed by single crystal X-ray structural determination. The similar product (S,4S)-2-(2′,4′,6-trimethoxy-4,6′-dimethyl-1,1′- biphenyl-6-yl)-4,5-dihydrooxazole (43) was converted into (S)-1-(2,4′,6′-trimethoxy-4,6′-biphenyl-2-yl)ethanone (57) which furnished (S)-1-(2′,4′,6-trimethoxy-4,6′-dimethyl-1,1′-biphenyl-2- yl)acetamide (58) (43%) and (S)-2,7′-dimethoxy-3′,5′,6-trimethylspiro[cyclohexa-2,5-diene- 1,1′-(1H)isoindole]-4-one (61) (30%) on Schmidt rearrangement. The dienone (61) on reduction and methylation regenerated the ketone (57). The methodology of Lipschutz was adapted for the synthesis of both enantiomers of 1,1′-(2′,4-dihydroxy-6,6′-dimethoxy-2,4′- dimethylbiphenyl-3,3′-diyl)bisethanone (32) and (83) which constitutes a formal synthesis of both enantiomers of desertorin C. CSIRO 2000.

Asymmetric synthesis of axially chiral biaryls via desymmetrization of 2,2′,6,6′-tetrahydroxybiphenyl using 1,4-Di-O-benzyl-L-threitol as a chiral template

Sequential etherification of 2,2′,6,6′-tetrahydroxybiphenyl (1) with 1,4-di-O-benzyl-L-threitol under Mitsunobu conditions gives desymmetrized biphenyldiol 9 of S-axial chirality exclusively. Cyclization of 9 with l, u-dibromoalkanes followed by removal of the chiral auxiliary yields (S)-2,2′-biphenyldiols 14 with alkylenedioxy bridges at the 6 and 6′ positions. (S)-6,6′-Dialkyl- and -diphenyldiols 20 are obtained in an efficient manner via Pd(0)-catalyzed cross-coupling of bis(triflate) derivative 17 with organozinc reagents. Bis(triflate) 17 also serves as an intermediate for asymmetric synthesis of axially chiral biphenyldicarboxylic acid 23, terphenylcarboxylic acid 28, lactone 26, and lactam 30.

A formal synthesis of both atropenantiomers of desertorin C

Asymmetric synthesis of both enantiomers of 1,1'-(2',4-dihydroxy-6,6'-dimethoxy-2,4'-dimethylbiphenyl-3,3'-diyl) -bisethanone allows the formal synthesis of both enantiomers of 4,4',7,7'-tetramethoxy-5,5'-dimethyl-6,8'- bicoumarin (desertorin C).

The first asymmetric synthesis of the naturally occurring (+)-Kotanin and the assignment of its absolute configuration

The first asymmetric synthesis of the naturally occurring (+)-Kotanin is described. The key steps involve the intramolecular oxidative coupling of the cyanocuprate intermediate and the Fries rearrangement. The absolute configuration of (+)-Kotanin was assigned as aS by CD spectroscopic method.

Asymmetric desymmetrization of 2,2′,6,6′-tetrahydroxybiphenyl by using 1,4-Di-O-benzyl-D-threitol as a chiral template

A general method for the preparation of axially chiral (S)-6,6′-disubstituted 2,2′-biphenyldiols is developed by using a highly enantioselective desymmetrization of 2,2′,6,6′-tetrahydroxybiphenyl.

The first enantioselective synthesis of optically pure (R)- and (S)- 5,5''-dihydroxy-4',4''',7,7''-tetramethoxy-8,8''- biflavone and the reconfirmation of their absolute configuration

The first enantioselective synthesis of the optically pure (R)- and (S)-5,5''-dihydroxy-4',4''',7,7''-tetramethoxy-8,8''- biflavone is described. The key steps involve the intramolecular oxidative coupling of the cyanocuprate intermediate and Friedel-Crafts rearrangement. Their absolute configuration was reconfirmed by CD spectra.