Biologically active amino ethers

Alkylations of phenols with epichlorohydrin under PTC conditions and microwave irradiation were described twice in 1998. Subsequently, ring-opening reactions of the epoxide group were also performed using microwaves (Eqs. 20 and 21) [31, 32]. In the first catalytic synthesis of chiral glycerol sulfide ethers was described [31] in the second biologically active amino ethers were prepared [32],... 

A very recent study presented by Dujardin et al. describes the complementary use of chiral enol ethers as dienophiles in oxa Diels-Alder reactions. This approach has yielded promising results with regard to the synthesis of enantio-merically pure carbohydrates [481]. Further noteworthy studies directed to the preparation of biologically active amino sugars from enaminoketones have been carried out in our group [110]. 

Owing to the different biological activity of D- and L-enantiomers of seleno-amino acids, the chiral separation of optical isomers has been undertaken in sele-nized yeast and in yeast-based commercial supplements. Both, chiral stationary phase (crown ether) and chiral derivatization prior to reversed-phase HPLC were used [16, 77, 78],... 

MCM-41-(CH2)3-NH-(CH2)2-NH2 was utilized for the cyanosilylation of carbonyl compounds to afford cyanohydrin trimethylsilyl ethers 98 (Scheme 3.27)," which are industrially valuable intermediates in the synthesis of cyanohydrins, (3-amino alcohols, a-amino acids and other biologically active compounds. ... 

Chlorosulphonation of the 3-methyl ether of oestradiol 17-acetate, and subsequent treatment with various amines, has given rise to a series of 2-sulph-amoyl oestratrienes, and a number of /V-substituted sulphamoyl derivatives of 17a-ethynyl-oestradiol have also been made. Methane- and butane-sulphonamido-oestra-l,3,5(10)-trienes prepared from the 3-amino-analogue of oestrone have shown poor biological activity. 

The Fuchs group has also prepared [15] dihydrocephalostatin 1 . In this synthesis (Scheme 9), the angular methyl group of keto alcohol 20 (obtained from hecogenin acetate) was functionalized by Meystre s hypoiodite method and oxidized to yield 21. Further reactions via intermediates 22 and 23 afforded 24, which was coupled with a-amino oxime ether 25 (prepared from 18) to give dihydrocephalostatin 1 after deprotection. This dihydro derivative had biological activity comparable to cephalostatin 1. 

The intramolecular 1,3-dipolar cycloaddition of isomiinchnones with alkyl vinyl ethers has been shown to proceed with complete diastereoselectivity. The cyclodehydration of cyclic A-acyl-a-amino acids yields bicyclic mesoionic compounds which react with A-(phenylmethylene)benzenesulfonamides to produce a new class of spiro-cyclic -lactams possessing biological activity. 

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